# fuel limit on CIS



## tyrone27 (Sep 7, 2001)

i know that with cis-e the HP limit is 170 because the injector can't flow enough. but can i use the cis-m injectors or volvo 240 turbo injectors with a fuel prerssure regulator. because the cis-m injectors support up to 240 hp and the volvo injectors supports up to 250 hp. 


[Modified by tyrone27, 5:58 PM 6-13-2002]


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## psi (Oct 18, 2001)

*Re: fuel limit on CIS (tyrone27)*

I believe the injectors are the same(Volvo/VW),so that won't do anything.To make this work you need the whole 240T fuel dist.There are some goons here that I talked into running this unit,and they all seem to have good results(although they are chicken to turn up the boost







).


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (psi)*

How high do I need to go?
I'm thinking about building a G60 bottom end and throwing it in my car. I would run at least 15 psi, I hope.
(I'm running ghetto-stacked head gaskets right now)
Right now I'm running without a knock sensor ignition (this will change very soon), and I get audible ping at around 12 psi and < 3500 RPM. It seems to clear up above that, but the boost drops a bit as well.
10 PSI is what I am running now, sort of.
-Steve (running a Volvo 240 setup)


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## tyrone27 (Sep 7, 2001)

*Re: fuel limit on CIS (Stephen Webb)*

well what is a cis system i can use that i can take it up to about 250 hp before I go stand alone. i'm basically trying to run on the stock motor with lowered compresion and then when i build my race motor go stand alone. i'm in to street racing so it would be good to crank up the boost. plus i meet a lot of hondas on the highway when i go to work.


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (tyrone27)*

The guys with Volvo 240T's usually start going lean under boost at about 220-240hp from what I've read. Look around on the net, there are some killer Volvo sites. Sweedishbricks and Turbobricks are two good places to start. 
If you retrofit your VW CIS with the full Volvo 240t CIS, you'll have a max output of about 220-240 fuel wise. Of course that doesn't take into account the timing aspects, or the low CR's of the Volvo motors.
You could probably get a few more without going lean under boost by running a pressure activated switch to run either the cold start injector or to ground the O2 sensor to get more fuel. You might be able to make that power without doing too much voodoo.
What are your plans on retarding the timing under boost?


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## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Stephen Webb)*

E-mail me with your adress,and I'll send you a knock harness and knock box.I want to see more boost!


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Stephen Webb)*

Steve, what motor are you running the stacked gaskets on? Any problems with leakage? Any idea about the drop in CR? Thanks







You might want to look into a Saab's APC system for knock retard of boost level. Pretty neat junkyard stuff








If you're running plain CIS-lambda I've heard you can also run an early Rabbit distributor with the dual ports on it. It will retard ignition timing under boost if you hook your manifold pressure to the advance port. Boost will bleed through the retard port.


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (tyrone27)*

quote:[HR][/HR]well what is a cis system i can use that i can take it up to about 250 hp before I go stand alone. i'm basically trying to run on the stock motor with lowered compresion and then when i build my race motor go stand alone. i'm in to street racing so it would be good to crank up the boost. plus i meet a lot of hondas on the highway when i go to work.[HR][/HR]​I suggest you build a 200 HP motor to start with. I think you might be surprised how fast that will make your car, and it's a reasonable target. 250 as a starting point out of a 1.8 is pretty aggressive, I think.
-Steve


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

Running it on a JH engine that was originally set up for NA power. 
I milled .060" off the head, and .040" off the block (and about .010" off the tippy tops of the pistons, as they were nearly hitting the head)
This setup yielded around 10:1 compression and ran very strong (with a big cam). When I switched to boost, I did the ghetto-stack for comp reduction. I figure I'm down to 9:1 or thereabouts.
-Steve


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Stephen Webb)*

Nice. I'm running a stock CR ABA bottom with a lightly milled head, for about 10:1 as well. I was hoping double gaskets would get me about 9:1. I really should find the number for the compressed thickness of the gasket and do the math for it, but that's time. 
Steve, how's the car running, and at what boost do you start to see problems?


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## tyrone27 (Sep 7, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

i was going to run a MSD boost master and retard the4 timing for every pound of boost I run. whats the max boost i can use for the CIS-E system. i'm trying to run about 10psi can i use shims or change the injectors or use a fuel rising fuel pressure regulator?


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (tyrone27)*

Are you going to run the whole MDS6 ignition too? I really don't want to do away with the stock Bosch stuff, but I've never seen just the BTM hooked up to a stock Bosch ignition. Can it be done? 
Max boost pressure will depend on how much fuel you can deliver, and how prone to knocking the motor is. 
You might want to look into other CIS-e cars with higher power outputs to find a retrofit fuel distributor like we're all trying to do. Perhaps an older Audi 5kt or 200t would work with a port blocked off.


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (need_a_VR6)*

For 250hp, look at a Mercedes V8 fuel dist. I saw one on Ebay go for $71 last week. 
Although I gotta say Steve is making alot of sense, try a 200hp motor first. It will beat 95% of everything that's on the roads today, be darned fast, and probably alot easier on diffs/gearboxes than 250. Walk before you run.....


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

quote:[HR][/HR]For 250hp, look at a Mercedes V8 fuel dist. I saw one on Ebay go for $71 last week. [HR][/HR]​Andrew, would it make more sense to run it with all 8 injectors, or just block 4 ports? Has anyone ever run one sucessfully with non factory blocked ports?


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## Vwsport.com (Mar 30, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

there is a MSD btm that is for stock ignitions, I am still trying to get my damn 16v running run on euro cis. I lean out at about 4k rpms, and only 4-5psi but I made 170 somthing wheel torque at 4krpms on 4 psi







too bad I did not make it to the fun spot. but the btm worked perfectly with the knock box. no pinging on pump gas (I know its low psi, but I need to get more fuel in) I now have a cool computer programable extra injector controller, so I am going to run 4 extra injectors, but I am still trying to find someone to fab up a basic fuel rail and tap / mount the 4 extra injectors on the runners. once all that is done, I expect some good numbers from the stock 2.0 16v. 
Dan


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## Vwsport.com (Mar 30, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

there is a MSD btm that is for stock ignitions, I am still trying to get my damn 16v running run on euro cis. I lean out at about 4k rpms, and only 4-5psi but I made 170 somthing wheel torque at 4krpms on 4 psi







too bad I did not make it to the fun spot. but the btm worked perfectly with the knock box. no pinging on pump gas (I know its low psi, but I need to get more fuel in) I now have a cool computer programable extra injector controller, so I am going to run 4 extra injectors, but I am still trying to find someone to fab up a basic fuel rail and tap / mount the 4 extra injectors on the runners. once all that is done, I expect some good numbers from the stock 2.0 16v. 
Dan


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (need_a_VR6)*

Hey Paul, 
Whew, finally made it back to Vortex. I was "locked out" for a week. 
Anyway, I don't know if you'd plug 4 ports or use 8 lines. I'm still trying to figure this out myself. I can concieve of ways to use all 8 lines, but not sure how to tune it or trigger the extra 4 lines. I'm thinking that if you have all 8 spraying all the time, you'd have to lean it so much when you're not in the boost that it might not do what you need when you do get into the boost. I was just reading earlier todday, someone mentioned a junkyard turbo rabbit doing the quarter in the 13s, less than $1500 invested in the whole project, and using a Mrecededs V8 fuel dist. I can't seem to find the post now. He was using all 8 lines, however, and some way to "bring in" the extra 4 when needed. 
For those of us that are fans of the old school and CIS in general, a boosted VW with twice the amount of stainless steel braided fuel lines under the hood would be very sweet indeed. Dunno why, but I get all warm inside picturing a low comp 4 cyl vw motor being fueled by a V8 fuel dist http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 


[Modified by Andrew Stauffer, 2:21 PM 6-14-2002]


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

quote:[HR][/HR]Nice. I'm running a stock CR ABA bottom with a lightly milled head, for about 10:1 as well. I was hoping double gaskets would get me about 9:1. I really should find the number for the compressed thickness of the gasket and do the math for it, but that's time. 
Steve, how's the car running, and at what boost do you start to see problems?[HR][/HR]​IIRC my head gasket thickness was 1.62mm compressed (eyeball average of about 10 measurements) It was not the metal three layer type, but the standard 8v 1.8 head gasket.
I start to get audible ping in the 11-13psi neighborhood below about 3500 RPM. By 4000 RPM the ping seems to be totally gone (unless I jack the boost even more)
-Steve



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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

quote:[HR][/HR]
Steve, how's the car running, and at what boost do you start to see problems?[HR][/HR]​car is running not boosted right now, BTW. But, when it was running last, holy friggin hell. Fun, fast, dangerous.
First gear traction is a no-go, and second gear only holds on nice roads.
-Steve


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

quote:[HR][/HR]Hey Paul, 
Anyway, I don't know if you'd plug 4 ports or use 8 lines. I'm still trying to figure this out myself. I can concieve of ways to use all 8 lines, but not sure how to tune it or trigger the extra 4 lines. I'm thinking that if you have all 8 spraying all the time, you'd have to lean it so much when you're not in [HR][/HR]​I don't know what would happen for sure, but I tend to think that it would work fine under no boost. 
The total amount of fuel being injected depends on the total amount of airflow. As long as the fuel gets distributed evenly between the cylinders, the correct amount would be delivered.
I see it like this: Take your V8 mercedes 4.0 liter engine at 500 RPM, flowing X amount of air, which requires Y amount of fuel (evenly distributed to each of the 8 cylidners). Now take your 2.0 liter 4 cylinder VW engine at 1000 RPM, flowing the same (X) amount of air, and requiring the same (Y) amount of fuel. The fuel distributor doesn't know how many cylinders are sucking away, all it knows is that a certain amount of air is flowing through it, which means a specified amount of fuel is required. 
So, as long as you can take the 8 outputs of the fuel distributor and divide them up evenly between 4 cylinders, it should be just fine.
Since 4 is half of 8, two injectors per port should perfectly distribute the fuel. (using a 6 cylinder fuel distributor ona 4 cylinder car in the same way would be harder because it's hard to evenly split the flow of two injectors into 4 cyinders)
The only rich problem you might have is if you are running near the minimum operating limit of the FD (at idle, say) but this seems unlikely. V8s tend to idle pretty low (500 RPM or so isn't unheard of) and our VWs are fine idling at 1000 RPM. So I doubt it would be a problem.
With electronic injectors (with minimum open times, etc) you might run rich, but with continuous injectors, I don't think it's a problem.
That's my $0.02
Does it sound reasonable?
-Steve


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Stephen Webb)*

It does sound reasonable, Steve. What's your thoughts on it's abilities to fuel under boost? If we follow your logic(and again, it sounds right), we may not see much benny under boost. I guess it depends on the flow bowl shape and control plunger slits to determine how much fuel under what condition.......
I've gotta get a few diff CIS fuel dist and start answering some of these questions. I've had them in my head for years


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Andrew Stauffer)*

This is a post Art Clemens made in the 16v forum.....
"I saw a cat down in Bradenton FL with this junkyard dog turbo Westmoreland Rabbit. It had an intercooler from some small diesel delivery type truck. Fuel distributor was from a V8 Benz CIS with 4 additional injectors mounted in the runners of the intake. He reluctantly acknowledged he had a spring mounted somehow to the airflow sensor to prevent overfueling at low end/no boost. It was all cobbled together and looked a little rough but it sure worked. HE had it running just a week and came in and laid down a 13 sec pass as I recall and then drove it home along with his buddy in a similar 8V turbo rocco. Dude said he had $1500 in the entire car. "
The point of me bring this over, besides the fact that I find it very intriguing, is to call attention to the spring trick described. I"m sort of puzzled(as usual) about how that would work, as if the spring prevented excessive lift of the flow plate at low rpms it would *really* hurt the higher rpms where the motor is under boost. 
Anyway, it isn't unprecedented...........


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Andrew Stauffer)*

oops...double post....


[Modified by Andrew Stauffer, 5:13 AM 6-17-2002]


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## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

The amount of fuel delivery for a CIS motor does not(Yes NOT!)have anything to do with the flow of the injector.All the injector does is atomize the fuel.
The amount of fuel is decided by the fuel dist(meter head on AFM).
4 ports=fuel for 4cyls,6ports=fuel for 6cyl,ect.
You figure it out,but the amount of fuel delivery is there for some really potent cars.Now get off you computer and build something!


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (psi)*

I think we're all in agreement on that issue, Chuck, no one was debating CIS injector flow rates at this point in time. Maybe earlier in the thread? 
The question in my mind has to do with the fuel passages through the fuel dist. If you have a 6 (or 8, or 5) port fuel dist and plugged some of the ports(ala volvo 240T) do you get more fuel returned to the tank and usual flow of fuel out the injectiors, or do you get 6 injectors worth of fuel out of 4 injectors? 
I guess I could model this with the extra VW CIS fuel dist that I have, just measure fuel delivery for all 4 lines, then plug 2 and measure again. Hmmmm.......


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## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

If you plug fuel lines it will not allow more fuel to go into the other open ports. All the ports are divided and are metered individually. The 8 ports being spliced into 4 injectors are the way to go. As a MB master tech for too many years I know the older 380 SL and S classes do idle at 500 rpm [So low they create customers bitching that the idles is rough]. They did raise it in 84-85 but the fuel dist is the same. I thought doing it with my project but with emission testing and what not it is easier to make a Volvo system appear to pass [looks do count when they look under the hood]. With fuel gauges there are many was to lean or richen a CIS system [as long as you want the whole fuel table to go up or down]. Because the air flow meter does flow down there is that concern too [too much butching for me].


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## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Andrew,
Even each port on the MB V8 flowed the same as the one on the Rabbit you'd still be up at around 1.5 litres per minute. Good for something like 300hp naturally aspirated. If it flowed more it would be all bonus... as for the overflowing issue I think you could take care of that with an EIC and a big injector mounted inline with the warm up regulator but downstream of it (return side). You'd need to pulse the injector to find 49-55psi which would be your base running setting, then if it was overfueling just pulse it less to restrict the flow (upping control pressure) to keep the plunger down.
The MB units are also downdraft so you'd have to replumb for that like I did with the 924t unit.
As for fuel unions to tie 2 into 1 - Porsche made unions for this purpose for the Porsche 924 GTS (which used the MB V8 fuel distributor). Ok now I'm sharing my research... the fuel block part # for that block at porsche is 931 110 041 01. I'm not sure if the line and the block all tie together though. Not even sure if you can order that part this side of the atlantic...I believe there are also some Volvo parts made for this purpose - but racing parts only...
Hope this helps,
Peter Tong


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## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Peter Tong)*

Yea thats how I saw it done(been a while).
I gotta stop posting after closing the bar














.


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Butcher)*

quote:[HR][/HR]If you plug fuel lines it will not allow more fuel to go into the other open ports. All the ports are divided and are metered individually. The 8 ports being spliced into 4 injectors are the way to go. [HR][/HR]​If this is true, then the using all 8 fuel outlets and using unions of some sort. My question is, is there a good way to *really* test this to make sure?
On CIS isn't there just the one control plunger that controls all the injectors (and their flow rate) from the center of the control unit? If so, wouldn't blocking a port just eliminate the pressure drop across that fuel dist port, and that would make a change to how the plunger was acting at the time? I think we should really think about this, and then devise a test to make SURE it was right!
The only reason I'm doubting is the Volvo 240 CIS and Audi 5kT CIS are just 6cyl bodies with ports blocked from the factory. Why not just use 4cyl distributors if blocking the ports "does nothing." 
The limit of the Volvo CIS on a VW hasn't really been pushed. It would be nice, though, to have a fairly easy option to switch too when you're finding your CIS turbo car going lean because of the limit of the fuel metering device!
That all being said, anyone know what a stock fuel pump is good to?
Anyways that's my $.02


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (need_a_VR6)*

Stock fuel pumps (for CIS) are tremendously capable due to the higher pressures they run. IIRC, they will support 300 hp. Some EFI guys end up running CIS pumps when the OEM unit is no longer sufficient. 
"On CIS isn't there just the one control plunger that controls all the injectors (and their flow rate) from the center of the control unit? If so, wouldn't blocking a port just eliminate the pressure drop across that fuel dist port, and that would make a change to how the plunger was acting at the time? I think we should really think about this, and then devise a test to make SURE it was right!" 
Good call. I'm with you on the one control plunger fueling all the injectors, but what of the fuel return line? If the fuel wasn't able to flow out of a blocked port in the fuel dist, I'm not sure it would effect the control plunger, but may just force more fuel to be returned to the tank. Not saying this is what happens, but that's the question reading your post brings to mind...... 



[Modified by Andrew Stauffer, 5:15 AM 6-17-2002]


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

quote:[HR][/HR]Stock fuel pumps (for CIS) are tremendously capable due to the higher pressures they run. IIRC, they will support 300 hp. Some EFI guys end up running CIS pumps when the OEM unit is no longer sufficient. 
Good call. I'm with you on the one control plunger fueling all the injectors, but what of the fuel return line? If the fuel wasn't able to flow out of a blocked port in the fuel dist, I'm not sure it would effect the control plunger, but may just force more fuel to be returned to the tank. Not saying this is what happens, but that's the question reading your post brings to mind...... [HR][/HR]​Thanks for the word on pumps, I guess I won't worry about it until it dies (it is a Rabbit and the fuel pump will die!). 
I guess I'll have to look at the Bosch book tonight and see where that fuel would go. Hopefully it won't go back to the tank!


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (need_a_VR6)*

Well, what ever fuel isn't injected does get returned to the tank under most circumstances. Maybe under all circumstances. 
So if you have plugged ports in the fuel dist, from what's been said in the posts above, it's going back to the thank. 
What remains a mystery to us, then, is the Volvo 240T fuel dist. Why a 6 port fuel dist with 2 plugged ports? Perhaps it was easier/cheaper from a materials and manufacturing perspective for Volvo to buy/spec one fuel dist that was then just modified by plugging the two ports. Or maybe not. 
If the ports on the Volvo 240T fuel dist were somehow interconnected to equalize pressure between all the open ports, then the 2 plugged ports could concievably contribute extra fueling. This, however, goes against what is being said by Butcher. Perhaps the 240T fd is an exception to the rule. Or perhaps I"m just over thinking it. I'm curious to know just what gives the Volvo 240 T fuel dist it's generous capabilities.....


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## jynssi (Jan 3, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

Sorry for being lazy and not reading all the posts...
So I don't know if this was mentioned, but in theory You could route all 6 ports into a single fuel rail, and then just attach four injector to it; -just like one does with EFI.
6-port dists have bigger capacities/port, than the 4-port ones. Often 6-port dists do have 2 dummy ports, either not even drilled open or just plugged,but without necessary internal parts to operate as the four ones in duty.
Some capacities can be found from:
some volvo guys page


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (jynssi)*

I don't believe that was measured, but it's a very cool idea! I was thinking of something along the same lines to utilize the MB V8 fuel dist, although I hadn't take the concept as far as a fuel rail. I was just thinking of brass unions, but your idea sounds alot cleaner.


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

Without reading the rest of the responses, here is what I think would happen under boost, and the benefits...
(as you mention, the shape of the cone and the slits and all that jazz will matter too!)
You still need a control pressure regulator, or "full throttle"(boost triggered) enrichment scheme, or some way to enrich uner boost. The big win for the V8 fuel dsitributor (in my eyes) is the increasede capacity of the unit. I don't know how much Mercedes squeezed out of those bad boys, but I have to believe they are good for more than the 170 that our FDs are good for. (I'd guess 340 just because).
So if you are going through the trouble to put an 8 cylinder FD in your car, you had BETTER be cranking up the boost! If the Volvo unit really is good for 240 (or even 220) I'd suspect you need 15 psi or so to hit the limit. 
Again, just my thoughts (I've never messed around with a big FD like that)
-Steve


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

quote:[HR][/HR] He reluctantly acknowledged he had a spring mounted somehow to the airflow sensor to prevent overfueling at low end/no boost. 
...
as if the spring prevented excessive lift of the flow plate at low rpms it would *really* hurt the higher rpms where the motor is under boost. 
[HR][/HR]​I agree that the spring deal sounds suspect. 
Maybe the guy who he was talking to wasn't the one who built the car, and when pressured for answers just made something up. Maybe he didn't understand the question...
I don't know. It sure doesn't sound right to me.
-Steve


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Stephen Webb)*

Yeah, there's alot of speculation going on there, although Art(that offered up the story) is a pretty knowledgeable fellow. He didn't elaborate at all. I should probably ask him about it. 
At any rate, rather than rigging a spring to keep fueling appropriate at low rpms, I was looking at an extra fuel dist/flow bowl that i have in the shop and thought that altering the counterbalance weight might achieve the desired results. Weight the plate end or lighten the counter balance to make it slightly harder to lift (or in the case of the MB V8, harder to lower) initially, but once there's significant airflow, it's up up and away. 
Of course, we'd be messing with something that alot of engineers have been paid alot of salary to make right, but hey, sounds great...........


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## Vwsport.com (Mar 30, 2001)

well I did some more playing today without much luck. the car still leans out around 4.5k rpms. I am running a stock 2.0 16v w/ euro cis and a t3 super 60. when it starts to lean out I glanced at the boost gauge and saw a whole 3psi. its perfect at 4k feels real good then i watch on the air fuel meter it go from rich to lean pretty quick. I put the warm up regulator by the fresh air intake for the car so that it does not warm up, that helped just a bit, I put two washers on the valve (shimed it) (if I tired 3 the car ran like crap) it didn't seem to do much. the fuel psi shows about 70psi most of the time, the fuel filter has been chaged and the pumps are good. is 70psi normal? I thought it was a bit higher? I played with those 4 screws by each injector (what the hell are they for? they do make a difference) you have to take the covers off b6 you get to the adjustment screw. I put them back to normal as it did not do too much. any ideas to try and get more out of this thing? I have a cool eic waiting to go in, but my friend it taking forever to make a fuel rail for 4 extra injectors. I know that will solve my problem, but I just wanted to play with cis a bit more. anyhow sorry for the long ass post.
Dan


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Vwsport.com)*

Andrew, you're completly right about not wanting to "re-engineer" some of this stuff, as I know modifing the arm is probably over most of our heads (especially mine)!
VWsport, there might be more things you can do for more fueling, but all the "tricks" I know are for CIS-lambda. There is a test in the Bentley (or Bosch book) that made me think of this: wire a pressure switch in line with the O2 wire. It would have to be a normally closed switch between the o2 and computer. Then when the ps opens, ground the pin to the ECU. This will kick the duty cycle of the valve waaay high and provide some extra fuel. Now on your car without the lambda probe, you might be able to get away with wiring the switch to ground a pin straight on the ECU!
Another idea that Peter alluded to is running a second freq valve either in series with the fuel return line or parallel with the normal freq valve. Use an EIC to control the freq valve (it's just a low impedance injector) and have the valve open up just before you start to lean out (if it's in parallel that is, it would have to lower it's cycle if it's in series with the fuel return). Problem is price as even the SDS EIC is about $320.
The ONLY problem with CIS is, once you're done with buying all the parts to make it work to a good amount of power, you could have bought an SDS standalone system. Programability as well as losing the restrictive air flow sensor.
That doesn't mean I'm giving up CIS though


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## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Vwsport.com)*

Dan, 
a)Which warm up regulator are you using? Is it a boost friendly version(volvo 240t, Audi 5k T, Porsche 924 T, etc?)
b) Did you readjust the af mixture after you shimmed the fuel distributor?
70psi is at the lower end of the range called for by Bentley- IIRC, 68-78 is the range. That would be worth double checking before you believe me, however.


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## Autocratic_1st_Gen (May 29, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

What about adding 4 injector bungs and using the V8 dist? By removing shims it would be easy to tune it for appropriate fueling at idle and with a boost tolerant warmup regulator it would be easy to enrich it under boost.
or run cold start injectors for the 4 extra and use a preassure switch so they only turn on under boost.
-Dustin


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## jynssi (Jan 3, 2002)

*Re: fuel limit on CIS (Autocratic_1st_Gen)*

In peugeot 205 t16 Gr.B there were two ports routed into a single injector. That way the capacity of all 8 ports were usable with 4 injectors. Like PSI said, all injectors do in cis is to atomize the fuel.
´furthermore this was done to prevent extra hoses, nozzles and openings from the system and to prevent poor fuel atomizing when idling.
Latter is similar problem with v8 dist on a 4-cyl engine than it is with large efi injectors. Engine consumes so small amount of fuel/injector, that the atomizing gets disturbed.


----------



## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (Autocratic_1st_Gen)*

I think most of you guys are missing the point about the MB fuel dist running too rich and what not. A fuel dist. does not care how big the engine is. The amount of sensor plate movement [air] will always distribute fuel to the proper ratio[as good as CIS can]. You must use all the injector ports or you will start cutting out the amount of fuel that you are distributing [in a V8 you will loose 1/8 the amount of fuel for each port plugged but the sensor plate does not know that]. It should never run too rich or too lean as long as you are using all the ports. That is why Porsche grouped the injectors in pair. They could of used all injectors but that would most likely complicate things and add more stuff to go bad. There are not many 4 cyl. engines that need to distribute as much fuel as some of the turbos can deliver. Since each port is a separate system [controled by one plunger] then each will deliver fuel individually. System pressure is most likely at 5 bar [or there abouts] and by plugging off one port will not add extra fuel to the other. Just like unplugging an electric injector will not add fuel to the other injectors. They are separate. If you remove the plunger and look very close you will see each port will have a slot that the fuel must go thru before the injector. The more that is uncovered the more fuel is delivered. Why Volvo used a dist with 6 ports is most likely due to costs [instead of being the only one that will use a large 4 cyl dist]. Remember this is a Bosch system that Volvo used. Bosch probably thought is was not worth the extra costs for only one manufacture [just my opinion]. CIS is a wonderful reliable system in the beginning of fuel injection. But the fuel is matched to the amount of the sensor plate. Changing one to another will screw up things. I know VW you can mix and match but that is because VW wanted to keep things easy.


----------



## antichristonwheels (Jun 14, 2001)

*Re: fuel limit on CIS (Stephen Webb)*

I spoke to the owner of the MB fueled turbo Rabbit. He was a Russian or Uke guy from the Tampa area Ivan was his name. Maybe someone can put out some feelers and find him. This was the race day of the 1552 show. I think he was being straight up about the spring but was surprised anyone asked. Somehow I doubt the first spring was perfect and he had to do some "spring tuning" Maybe its only purpose was to control fuel delivery under boost. Wish I know more. I was impressed with what he accomplished and it was funny to watch him come from behind and take out a V8 firebird on his 1st pass.


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (art.clemens)*

Here's a new twist on the limits of CIS for fueling a turbo set up......as per eBay...
Item # 1837998833
Item # 1837997562
Now....both of these warm up regulators are intended for Porsche 930 turbo cars. And one of them has been modified to be "adjustable" . Check out the pics for for more details. 
My question then is what the modified version accomplishes and how does it do so. Is it the overall fuel table that is adjustable with this unit? Or is the the boost enrichment that is adjustable? If it's the latter, these could be very key parts to a VW cis turbo set up. However, I suspect that it's the entire fuel table that is adjustable, same as shimming the control pressure regulator, and not specifically the boosted fueling.


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Andrew, it would be hard to tell what the adjustable one does without tearing it apart to see the guts. Pain in the butt that is. It does have a Bosch PN on it, so maybe it was used in other non-motorsport apps as well. Interesting to say the least.
Back to the idea to use an EIC to contol a parallel freq valve.. the SDS EIC can be configured to run the stock freq valve with only two resistors and the mod can be done at SDS for $15 before shipment of the unit. I just might do my fueling this way, could be more productive as the EIC can sense boost and load


----------



## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

A friend of mine used to work on a 930 for a customer and he installed one of these adjustable control pressure regulators. I will get the details on the unit this weekend, but as I recall it could be used to adjust overall control pressure at least. Maybe there was a separate setting for on-boost control pressure -- maybe the unit wasn't boost sensitive at all, I don't know. - I just remember the car idling, and my buddy was like "can't you smell how rich it is running? We put this adjustable CPR on there. Turbo Porsche's like to run really fat...blah blah blah"
I just bought some brass injectors (from some mercedes or porsche, I think...?) They are supposed to atomize the fuel better, and give more power, blah blah. Does anyone know anything about them?
-Steve


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Stephen Webb)*

Steve, 
Please do find out whatever you can about that adj 930 WUR, I'd love to know. The pic of them on eBay shows another port that leads me to believe it's boost sensitive, but what do I know about Porsche 930 stuff.......darned little........
Those injectors sound somewhat like the Volvo "gold" injectors that I've caught reference to now and again. That's little more than speculation(actually, that's NOTHING more than speculation), but it doens't seem a stretch to imagine that people would see brass as "gold"....


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Doh, and I thought they would really be gold!








Some info on that WUR would be nice!


----------



## Autocratic_1st_Gen (May 29, 2002)

*Re: fuel limit on CIS (need_a_VR6)*

I was thinking and I bet that just swapping on theV8 distributor with a boost dependant warm up reg will work. It may not be sensative enough off idle (it will run like it is carbed) but should deliver plenty of fuel. using T's with 4 injectors would probably work out to atomize best at idle, and it seems that they will flow plenty from what I have read. The warm up regulator will add fuel under boost to limit detonation too.


----------



## Vwsport.com (Mar 30, 2001)

*Re: fuel limit on CIS (Autocratic_1st_Gen)*

whatcha guys think of theses?? 
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll? ViewItem&item=1837825365&ssPageName=ADME:BN:US:1
these those gold injectors people talk about? I know the motrontic injectors flow more than the cie, I wonder what these flow. but from the looks of it the injectors are not the problem, the dizzie is.
Dan


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Vwsport.com)*

Draggin' this thread back up from the depths as I've found some new info at http://www.turbobrick.org. 
There, under "mods", is a page titled "A Low Cost Approach to Building a Hi Po B21FT".
That's the 2.1 liter Volvo 240 turbo motor as seen in the this country from 81-85(I think?)
They are making 250-280 hp on CIS at 20.5psi. They are fueling this by using(drum roll please.......) a Mercedes 450 8 pot fuel distributor(could use Porsche 928 as well) and "Gold" injectors. 
Gold injectors, they suggest, can be purchased through Stefannsson Automotive(SAM), part # 950822322. This is probably in Sweden or ?, but it's the most solid reference I've seen yet to the "gold" injectors...........fwiw.......


----------



## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

Thats where I read all that crap


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (psi)*

It's a fun article, although by the time you've build that CIS set up, I wonder how close you'd be to entry level programmable money. The Holley set up is ~$800, no? 
Never the less, if you like oldschool and CIS, that could be ALOT of fun. And it would be fun to say you've got Mercedes or Porsche fuel injection in your Rabbit


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Andrew, I remember reading that article as well! I just couldn't find it again when I wanted to reference it.
Anyways, I think you're right about standalone, it's looking nicer and nicer. SDS is only $1100-1300 with all the sensor and whatnot, and that includes the ignition control. What fun is "tuning" though if you can actually get things right the first time out


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (need_a_VR6)*

A few more interesting Volvo trivia bits. Again, if anyone wonders why the heck I'm posting Volvo stuff on a VW site, it's because the first three letters of each manufacturers name are the same








.........er, more accurately, it's to demonstrate what has been done with CIS on 4 cyl, 8v motors about 15 years ago. 
The power: 
up to 257 kW or 345 hp (with water injection) 
The injection:
Bosch K-Jetronic CIS (mechanical) injection with 8 chamber aluminium fuel head 
Injectors: Group A (Bosch 'Gold' injectors, (mechanical), 530 ml/min on 1, 2 and 4th cylinder, 580 ml/min on the 3 cylinder), (magnetic valves on 2 & 3rd injector to serve the antispin system - action - cuts fuel when spining) 
Air sensor plate changeable cones - to run with optimized control pressure at all revs, at different tracks 
Water Injection - modified Bosch Jetronic fuel injection (with airmass meter or map sensor, high pressure pump and four "yellow" Bosch injectors) 
Curious that the #3 cylinder gets more fuel, anyone know why that was necessary? 



[Modified by Andrew Stauffer, 2:09 PM 7-8-2002]


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Andrew,
Any idea of what a 240 intake manny looks like? One cyl probably ran lean and suffered knock because of it. If you're really that hardcore you can trace it back with EGTs. Wierd though.


----------



## Ryan 88 GLi (Jul 6, 2002)

*Re: fuel limit on CIS (need_a_VR6)*

-phew-, just got through this whole post. im planning on doing a cis turbo project next summer, and this was some good reading on it.
somewhat related question - what does autotech's "power module" for the CIS motors do exactly? It says that it is throttle position and rpm dependent, and will richen your fuel mixture as needed. whats the story?
personally, i am liking the sound of running the MB 8-cyl distro, maybe with 4 injectors, 2 lines to each injector? eh?


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Ryan 88 GLi)*

I guess you didn't read the three page thread before this one then, there's some good stuff in there too! 
I think the power module is only for CIS-e cars, but correct me if I'm wrong. 
The V8 dizzy sounds like a good idea, but no one has a part number for the unions needed to tie the lines together at the distributor.


----------



## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

Peter Tong has given out the number several times and I can get employee cost on Porsche parts [%10 above cost]. I would be willing to sell some one the unions [if there still available] at that cost if someone was going to try to use it. There is no doubt in my mind that is you can 'butcher' a Benz fuel dist. to your VW then you should be able to butch up some kind of union [butch in a good way]. That to me is all to simple.


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Butcher)*

Agreed, the the unions wouldn't be too tough. Certainly not the "hard part" of this equation. It could be as simple as a small block of brass that you drill a few holes in and tap them appropriately. 
Butcher, I'd be interested in the cost of those unions, I'm skeptical of current availability, but would like to explore the options. And out of curiousity, what does a new 928 fuel dist cost? Perhaps I should email you privately on these questions. 
While I'm sure this 8pot set up could be made to work and fuel a high boost motor(if it works for a Volvo 2.1 liter 8v, why wouldn't it work for a VW 8v?) there are a few downsides to keep in mind. The article that outlined the volvo motor suggested that plug fouling and 16mph with a light foot were common. I'd be willing to live with that myself, but my A1 isn't a daily driver. Oveall, this might be the way to boost a 16v motor and not run out of fuel due to CIS limitations without patching in AICs or Hobbs switches, etc. Not that those are bad in anyway, but my focus is doing it all with CIS. 
And fwiw, I emailed the shop in Sweden that used to sell the "gold" injectors. Let's see if they come back with anything. It's been 15 years since those cars were being built like that so availability is probably non existant, but somewere, out there, sitting in a box on the back of a shelf, under half an inch of dust...........


[Modified by Andrew Stauffer, 6:27 AM 7-9-2002]


----------



## Ryan 88 GLi (Jul 6, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

OK, I'm (obviously) no expert on CIS (at least not yet, ive only had my A2 for under two months), but I'm just going to pose an idea - why not use a v8 distro, such as MB in tangent with an Audi 5k warmup regulator, buy or fabricate a fuel rail, and run 4+ lines into the fuel rail? and the warmup regualtor would keep the mixture from being rich rich rich throughout the whole rpm spectrum.(?) Or, run all 8 lines into the rail, and put some sort of electrically controlled valves in 4 of the lines, put 4 switches in the dash, and have 5 different fuel levels you could run at for different levels of boost, (???) like, you could have 4-5 lines on for normal daily driving when you might not get above 4k rpm anyway, then hit a switch or two when the guy in the 5.0 is revving on you or youre at the drag strip. It's one of those things that is a good idea in theory, but i need someone to tell me if its possible.


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Ryan 88 GLi)*

The crew in Sweden doesn't stock the gold injectors anymore. I've asked if they know of a source, let's see what they comeback with.


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Did they say anything to the effect of, "who the heck still uses CIS?!?"


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (need_a_VR6)*

Heh, heh, they were more gracious than that, although I half expected someone on Vortex to offer that rhetoric.


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Andy, I do know they still sell the B21ET fuel distributor...
btw, the Cabby is runs pretty good on the Volvo 240t CIS-Lambda. I haven't even come close to flooring it and it really scoots at part throttle and 5 psi. Boost comes on as a function of throttle angle. This is with the stock Eurospec ABA pistons and the older style Eurospec head - something like 10.3:1 CR. I'm saving the $$$ to have the 9:1 JE's put in sometime later this month. The A2 manifold I'm running is also not ported to match the Eurospec head either (can you say huge mismatch?)...got to take care of that as well...
I noticed a small gain as well going with the new TT stainless 2.25" cat back with resonator. Its not a quiet exhaust by any means but it does idle reasonably quietly. Sounds nice when I'm on it...
regards,
Peter Tong


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Peter Tong)*

Good to hear, Peter. I'd guess that CIS is really only considered old school in emissions regulated parts of the world or the "developed countries" where marketing, emissions and innovation for the sake of innovation runs rampant. Parts of the rest of the world are probably pretty happy with CIS. Just a thought. I mean, they still make bugs in Mexico, right? Rabbits(er, golfs) in South Africa? Somewhere, out there, I'm sure there's still a good market for new CIS components. 

Are your pistons different than the stock OBD 1 ABA pistons? I have a Eurospec head from the early 90s, shaved .040" on a 95 ABA block, stock pistons, always wondered what the compression *actually* is. I know there are alot of cr calculators out there, but I still wouldn't be satisfied until I measured MY motor and MY head, etc to get actual #. Not gonna tear it down for the benefit of knowing, though. 
Anyway, back to CIS, how's the programmable aspect of your trick CIS set up working out? As intended? I'm certainly anxious to hear more when you're ready to pass comment on it................


----------



## Ryan 88 GLi (Jul 6, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

any comments on the audi 5k WUR + a v-8 distro with switches idea that i offered above? it seems to have gotten lost


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

Andy, I don't know what the actual CR is since it really isn't a stock ABA block - but rather the Eurospec Racing ABA. Its different from the ABA in that it doesn't have the hole for the crank angle sensor drilled through. I also wonder if the pistons are different. I believe that Eurospec rates the CR as either 10.3:1 or 10.5:1... my Eurospec head was also purchased around '95 or so...
I have a few things I need to fix - one of the brake line unions out back by the proportioning valves is leaking - need to tighten it down. I also purchased a 70mm 16v airbox which needs to go in - currently intake air is coming right from behind the rad - i need to plumb that to a cold air source first. Right now its getting hot air - not good. Its currently on stock timing...seems to run pretty good as is. I'll try to hook the laptop up as soon as the brakes are taken care of...and try various settings that map the CIS enrichment.
regards,
Peter T



[Modified by Peter Tong, 5:54 AM 7-10-2002]


----------



## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (Ryan 88 GLi)*

I think with a 380 SL or SEL [benz] fuel dist that should be small enough to meter the fuel at idle and large enough to allow the amount of fuel for the horse power anyone could use. 8 ports going to 4 valves is all you would need. Any additions switches and what not are more things to go wrong. Since the fuel dist evenly dist the proper amount of fuel to air in any given circumstance there is no real need to do too much butchering. The idle would be the worst part since that is the time that there is so little fuel being delivered that the CIS would have the toughest time. Since the early 380 motors idled at 500 rpm [and idled ok] then that should be fine with out 1.8-2.0 motors at 1000 rpm. I am not a math wizard and I just come from the school of hard knocks [and a few comebacks] but it sounds like it would work just fine. The warm up regulator from the audi might be ok but fuel delivery would not be the concern with this set up. I have never used this either just though about it in my mind.


----------



## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Peter Tong)*

My wife has an 88 cabriolet(cis)and I just made a manifold and downpipe for it.


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (psi)*

Just a little pic I accidentally posted in here, but it's interesting to say the least, courtesy of Mike Lane, through Andrew S.








I would be working on the fuel mods too, but I'm down with a broken rear brake line. Bugger.








(edit note: I was supposed to post that pic in another thread in the 8v forum for something else. I'm a moron and posted it in here by accident. Anyways, I'll leave it here because it's CIS oriented. Cute pic too







)


[Modified by need_a_VR6, 9:46 AM 7-10-2002]


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (psi)*

quote:[HR][/HR]I believe the injectors are the same(Volvo/VW),so that won't do anything.To make this work you need the whole 240T fuel dist.There are some goons here that I talked into running this unit,and they all seem to have good results(although they are chicken to turn up the boost







).[HR][/HR]​Chuck, I'm not too chicken to turn up the boost - I'm just chicken to do it with the stock 10:1 ABA pistons







Once the JE's are in I'll bring her over to the dyno and see where the 240t starts to go lean! As it is - I barely break open my secondary on the TB and I'm at 5psi - the rpms don't seem to matter. Can't wait till I can actually floor it. 
regards,
Peter T.



[Modified by Peter Tong, 3:18 PM 7-11-2002]


----------



## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Peter Tong)*

Hurry up!


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (psi)*

Hey Chuck and Steve, 
Were'nt we debating whether or not you could bypass the dpr on a CIS e fuel dist not so long ago? Heh, might even be in this thread.......
What where the conclusions to that conversation? There's a MercBenz 8pot dist on eBay right now, but it looks like CIS-e to my eye, curious if that's a useable part for my Frankenstien ideas.......


----------



## hasapiko (May 30, 2002)

*Re: fuel limit on CIS (psi)*

quote:[HR][/HR]The amount of fuel delivery for a CIS motor does not(Yes NOT!)have anything to do with the flow of the injector.All the injector does is atomize the fuel.
The amount of fuel is decided by the fuel dist(meter head on AFM).
4 ports=fuel for 4cyls,6ports=fuel for 6cyl,ect.
You figure it out,but the amount of fuel delivery is there for some really potent cars.Now get off you computer and build something![HR][/HR]​Am I missing something here? If I read my Bentley right, the injector will pass 120 ml/min at WOT. This works out to ~2.0 gal/hr, or 8 gal/hr for all 4 injectors. That is the fuel requirement for ~100 BHP, so the injector needs to flow ~ double that at 12 psi boost. So either the system IS limited by the injectors, or (so you're telling us) there is a major additional pressure drop in the system somewhere between the pump and the injectors even at WOT. Can you please explain where that pressure drop is? If it exists, wouldn't it be simpler to eliminate it rather than go to the trouble of replacing the whole system?


----------



## hasapiko (May 30, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

quote:[HR][/HR]This is a post Art Clemens made in the 16v forum.....
"I saw a cat down in Bradenton FL with this junkyard dog turbo Westmoreland Rabbit...
The point of me bring this over, besides the fact that I find it very intriguing, is to call attention to the spring trick described. I"m sort of puzzled(as usual) about how that would work, as if the spring prevented excessive lift of the flow plate at low rpms it would *really* hurt the higher rpms where the motor is under boost. 
Anyway, it isn't unprecedented...........[HR][/HR]​I also think this intriguing. This idea in principal should really work. The problem is that with the compressor supplying like twice the stock airflow the plate would normally be pegged well before full power is made. Restraining it with a spring calibrated so that the plate just opens fully at max output would then theoretically give you a plate displacement proportional to airflow all the way from idle to full power. Of course the amount of fuel flow per unit plate movement would have to be recalibrated...


----------



## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (hasapiko)*

At some point of time the injector could be the limiting factor but not with what anyone has here. If you put all the injector lines from a V8 fuel dist to one injector then the injector would most likely be the limiting item. But if your not going to pair up injector ports then don't worry about the injector. Most people seem to get confused about higher flow injectors and that is not the case with the CIS system since the injectors do not regulate fuel. 
The fuel dist. and airflow housings are paired up together and work in harmony to distribute the right amount of fuel to air. Any tampering with springs and what not as far as I am concerned is shear butchery and may be able to be done but not very consistant and I would not spend any additional time with that theory [excessive butching is not good].


----------



## sirhc (Sep 23, 1999)

*Re: fuel limit on CIS (Butcher)*

I like the spring idea. I plan on getting my car running on euro CIS w/ the audi boost sensitive wur, and we'll see how far that takes me. I'm thinking a v8 dizzy with lines paired down to the 4 injectors. Normally, this would be way to much fuel, so a small spring would aid in limiting the flow. Once you were at wot, the airflow would force the plate full open, giving you loads of fuel. 
As it was stated earlier, probably not the most accurate way to deliver fuel, but it would be cheap and easy if you could get it configured right.


----------



## Ryan 88 GLi (Jul 6, 2002)

*Re: fuel limit on CIS (sirhc)*

i think all of you "spring guys" could save yourselves lots of trouble with these springs by just rigging up something like 2 Hobbs switches on 2 extra fuel lines from a 6-pot CIS fuel distro (like from a porsche), with the swiches set to activate at 2 different boost levels (like at 6 psi and 10 psi or whenever you start going lean) just squirting fuel into the IC tube (to the TB). that way you dont have to worry about adding a WUR or any of that. this would be a little more money, but a lot less hassle and a lot more reliable. 
edit:: Also - your fuel could be regulated as per boost instead of as per RPM, which is what you want in a turbo system anyway, i would guess!


[Modified by Ryan 88 GLi, 6:23 AM 7-15-2002]


----------



## sirhc (Sep 23, 1999)

*Re: fuel limit on CIS (Ryan 88 GLi)*

That would work well too...


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Ryan 88 GLi)*

I'm sure that would work, and might work well, BUT I really don't like the thought of switches turning my fuel supply on and off. It's a little too discrete in nature to give proper performance all the time, which MIGHT be possible with a modded CIS setup. 
Chris, that thing running yet? Sheesh.. I still need a few parts and could use some inspiration!
Peter, just turn up the boost, a few shattered pistons never hurt anyone


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (need_a_VR6)*

quote:[HR][/HR]
Peter, just turn up the boost, a few shattered pistons never hurt anyone







[HR][/HR]​The local Bosch fac. that is installing the JE's won't use the Total Seals - as such need to go back to JRC to get the appropriate JE rings. I think I'll finally get the laptop hooked up tonight and see how things go adjustment wise...
Peter


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (psi)*

Alrighty then......we've had alot of good conversation concerning CIS in this thread. But, I don't think we've actually adressed the issue of the limits of CIS. 
So I'll ask which CIS fueled cars have made the most hp? I suspect it will be a Porsche turbo or 928, but I'm not that familiar with their performance #s. Anyone know? 
I've been studying Volvo's alot lately as my boost project uses ALOT of Volvo parts. Volvo had a 2.1 liter 8v motor in "Group A" trim(not really sure what that means, but it's a hot motor) that put out 225hp at 5700rpms and 250 ft lbs at 3300 rpms at 15psi. It ran K basic, although I don't know if it was a 4 pot or 8 pot set up. And of course, there's the write up that I mentioned earlier where they ran 20 psi and got 250-280hp with an 8 pot fuel dist, K basic being the prefered set up. 
What other hi po turbo cars came with CIS? What were their hp and tq #s? Where the Audi Group B rallye cars CIS injected?


----------



## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

924 turbo carrera turned in some pretty good #s.


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

1992 911 3.6 turbo put out 360+ hp using CIS...
regards,
Peter Tong


----------



## hasapiko (May 30, 2002)

*Re: fuel limit on CIS (Peter Tong)*

quote:[HR][/HR]1992 911 3.6 turbo put out 360+ hp using CIS...
The good folks at Fast Enough Performance keep fighting me on this one. When I asked them about using CIS-E with a turbo (i.e., the existing system on my 87 Golf GT) they said CIS - yes; CIS-E - no!. The reason: CIS is boost sensitive, CIS-E is not. And the proof: Audi used CIS thruout the late eighties -early nineties on their turbo cars, NOT CIS-E, tho it was available. And apparently the same is true with Porche. I guess with CIS you just get bigger injectors and off you go (sorta).
By the way, they say use the G60 injection system and be done with it, ie, it's not worth the development pain of modifying the CIS-E. I still like the idea of spring loading the flowplate but realistically I will pay the $600 and convert. 
regards,
Peter Tong[HR][/HR]​


----------



## Rabbit6 (Dec 16, 2000)

*Re: fuel limit on CIS (tyrone27)*

How about a twin CIS system. One cis unit does two cylinders. You'd need a custom intake manifold, perhaps bolted to an ABA crossflow head, that would install two injectors per cylinder, and one throttle body for two cylinders... even with stocker rabbit injection w/ audi 5000T control pressure regulators, you'd have an instant (2x170) 340 hp. PRESTO!
Just an idea...


----------



## Racer_X (Jul 14, 2002)

*Re: fuel limit on CIS (Rabbit6)*

quote:[HR][/HR]How about a twin CIS system. One cis unit does two cylinders. You'd need a custom intake manifold, perhaps bolted to an ABA crossflow head, that would install two injectors per cylinder, and one throttle body for two cylinders... even with stocker rabbit injection w/ audi 5000T control pressure regulators, you'd have an instant (2x170) 340 hp. PRESTO!
Just an idea...







[HR][/HR]​If you were good with welding on the intake castings, you could use an A2 manifold (TB on right side) for cylinders #1 and 2 and an A1 manifold (TB on left side) for #3 and 4.
I've heard of people using two rabbit airboxes, fuel distributors and systems on a V8 engine. I seem to remember somebody at least talking about doing that to an old Studebaker 289 V8. I think I've heard of it being done to other V8s, too.


----------



## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

What engine had the most hp? I do not know but MB had a 6.9 liter engine that had a lot of power [torque]. With US emissions it might have been choked down a bit but with a EURO machine I do not know how much power. I think AMG did some serious power with the 6.9 Machines. AMG also did a 4 valve V8 engine that had close to 400 hp with CIS [with a 117 engine].


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (Butcher)*

Butcher, the 6.9 made 250hp, 360 ft.lbs of torque at rather low rpm. Alot less hp than the 911 turbo 3.6...which made 360hp on paper, but some say lots more in reality...


[Modified by Peter Tong, 6:54 PM 7-21-2002]


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Peter Tong)*

So it would appear that the limits to CIS are few in an absolute sense, although the high end practicality or applications may be few?


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Peter Tong)*

So it would appear that the limits to CIS are few in an absolute sense, although the high end practicality or applications may be few? Were coarse generalizations to be drawn, the limits of CIS may(*may*) be drawn at 200hp/tq?


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Peter Tong)*

So it would appear that the limits to CIS are few in an absolute sense, however the limits of CIS may(*may*) be drawn at 200hp/tq? 
This, then, would be the generalized limits set by Justin( aka Red Rotors) at the Hardcore page and explain why there are no CIS cars there. 


[Modified by Andrew Stauffer, 6:13 AM 7-28-2002]


----------



## tyrone27 (Sep 7, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

what are you'll 8v CIS turbo cars running in boost


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (tyrone27)*

The Autorotor is pumping 5-6 psi right now on stock ABA pistons. Final boost (after the JE's go in) will be whatever gets me to just over 200hp... I'd like some semblance of reliability. 
Peter Tong


----------



## Racer_X (Jul 14, 2002)

*Re: fuel limit on CIS (art.clemens)*

quote:[HR][/HR]I spoke to the owner of the MB fueled turbo Rabbit. He was a Russian or Uke guy from the Tampa area Ivan was his name. Maybe someone can put out some feelers and find him. This was the race day of the 1552 show. I think he was being straight up about the spring but was surprised anyone asked. Somehow I doubt the first spring was perfect and he had to do some "spring tuning" Maybe its only purpose was to control fuel delivery under boost. Wish I know more. I was impressed with what he accomplished and it was funny to watch him come from behind and take out a V8 firebird on his 1st pass. [HR][/HR]​Art,
Did you see his car? under the hood?
I just picked up a MB mixture control unit (fuel distributor plus air flap and housing) from a 1979 6.9. (Actually, I have two, and once I clean both of them up and test them, if they both work, one might be for sale here.)
It looks like there's two possible ways to use this thing. The first would be to use the whole thing. Some issues there would be first that if flows down instead of up like ours. Also, it's quite a bit bigger, so it might not fit without moving the battery. I'm looking for an excuse to put the battery behind the passenger seat anyway, so that might not be an issue for me, but for some folks that could be a problem. I'm considering this option, and just sticking a big cone filter on top of it to filter the intake air and walling off a small cold air intake box behind the left hand headlight. When I really want to go, I can take the headlight out for more air flow.
The second possibility would be to bolt the 8 cylinder fuel distributor block onto the top of the VW air flap and housing. It looks like this is possible, but I haven't disassembeled everything yet and measured to be sure. If you do that, the biggest issue would be that the MB air flap has easily twice as much area as ours. If he did that, he might have used the spring to reduce deflection by the correct amount so that it wasn't overfueling because his flap was deflecting so far. The same thing might be accomplished by weighting the air flap, too. Of course, a spring isn't affected by cornering forces, so that might be a better solution.



[Modified by Racer_X, 4:31 PM 7-28-2002]


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Racer_X)*

As this has turned into quite an interesting and informative thread on the ability and tuning of CIS, here's another tidbit.......... 
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1847730214

I'll cut and paste to save you the financial jeoprady of going to eBay:
"This is a system that I designed for my SCCA VW Scirocco racecars so that I could tune the air/fuel mixture from the driver compartment while on the track. It allows you to maximize horsepower from your stock VW CIS or CIS-E fuel injection. It has undergone extensive testing on my car and several other SCCA VW race cars. There are many SCCA VW racers using my kit right now. It is a parts list and set of installation instructions to install an adjustable fuel control pressure system for CIS VW's. It works on all A1 Rabbit / Scirocco cars w/ CIS and A2 Golf / Jetta w/ CIS-E. 
It adjusts the control pressure using a stock, unmodified fuel pressure regulator (warm up regulator). You will need an EGT (exhaust gas temperature) gauge to monitor/adjust the mixture. With this setup, you can adjust your EGT from 1300-1500F from inside the car while racing. No modifications are necessary to the CIS system. Can be installed in one evening. 
SCCA legal! I have satisfied customers using this system right now. 
It includes a parts list and installation instructions, with phone numbers of vendors and part numbers required. The whole parts kit can be purchased from the vendors for less than $50 (not including the EGT gauge). You will need to contact the vendors listed to purchase the parts. 
***This auction is just for the parts list and installation instructions. NO ACTUAL PARTS are included!*** 
This can be sent via an e-mail attachment (free shipping!) or via U.S. Mail ($0.50 for postage and envelope"
I dunno anything about this just yet, sounds pretty similar to the adj Porsche CPRs we talked about earlier. Costs $20 to buy the plans/parts list outright, I'll probably get it out of curiousity........ 

[Modified by Andrew Stauffer, 4:14 AM 8-2-2002]


[Modified by Andrew Stauffer, 6:05 AM 8-2-2002]


----------



## TURBOCADDY (Jan 17, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

anyone want to play with a audo 5000 turbo fuel distributor i have a extra in my garage needs to be in a turbo rabbit somewhere 
thanks jake


----------



## Racer_X (Jul 14, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

I've seen a mod like the one you linked to. I'm not sure if it's the exact mod he's selling.
The ones I've seen have pulled the warm up regulator off of the engine block and put a screw on the back. Turning the screw will adjust the control pressure delivered by the regulator. I've only seen it installed under the hood. I'd be really nervous about locating the regulator and fuel lines inside where the driver can adjust it. Maybe he's using some kind of cable arrangement for adjustment and keeping the regulator itself under the hood.
In my experience, (and over 80 hours of testing on the track), this arrangment won't produce better lap times than a stock 1983/1984 CIS-lambda system (with the full throttle enrichment). If you have the older CIS-lambda system without the full throttle enrichment, you can upgrade to the system from the later models with the full throttle enrichment, or you can install a full throttle switch and hook it to the oxygen sensor to accomplish full throttle enrichment.


----------



## Rabbit6 (Dec 16, 2000)

*Re: fuel limit on CIS (Racer_X)*

Isn't the full throttle enrichment function on lambda CIS a switch to open loop operation? Cutting out the O2 sensor function, and essentially reverting back to basic CIS operation at whatever fuel ratio the unit is set to? (going from best emmisions active O2 closed loop to basic setting)


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Rabbit6)*

Rabbit6, yes, that's exactly how it works. The problem is when the basic fuel setting at the distributor is not rich enough, or can't be made rich enough all the time to ensure proper running under boost. At some point the stock fuel system will start to go lean, though I'm unsure exactly where that point is.


----------



## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (hasapiko)*

quote:[HR][/HR]
Am I missing something here? If I read my Bentley right, the injector will pass 120 ml/min at WOT. [HR][/HR]​I think I have read that part of the manual. It's probably accurate for what fuel system will deliver at WOT, about 100 HP worth of fuel. That makes sense as the engine is rated at about 100 HP. 
What the manual doesn't tell you is how much fuel the FD can deliver when the flap is raised all the way. At "WOT" the fuel flap isn't near the top of it's travel.
-Steve


----------



## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Rabbit6)*

quote:[HR][/HR]Isn't the full throttle enrichment function on lambda CIS a switch to open loop operation? Cutting out the O2 sensor function, and essentially reverting back to basic CIS operation at whatever fuel ratio the unit is set to? (going from best emmisions active O2 closed loop to basic setting)







[HR][/HR]​It doesn't necessarily go to the "basic setting" as with plain old CIS because it still uses the frequency valve. I think different years were different, but on my '89 cabriolet it runs the frequency valve at 70% during full throttle, I think. It is open loop operation, but it should be running richer than the basic setting.
It will start to run lean as the FD flow plate runs out of travel.
(the HP numbers people tend to throw around are 170 HP from the stock unit, and 220+ from the 6 cylinder casting / 4 cylinder Volvo turbo unit)
-Steve


----------



## Racer_X (Jul 14, 2002)

*Re: fuel limit on CIS (Rabbit6)*

quote:[HR][/HR]Isn't the full throttle enrichment function on lambda CIS a switch to open loop operation?[HR][/HR]​Yes, it cuts the controller over to open loop with an 80% duty cycle on the frequency valve.
quote:[HR][/HR] Cutting out the O2 sensor function, and essentially reverting back to basic CIS operation at whatever fuel ratio the unit is set to? (going from best emmisions active O2 closed loop to basic setting)







[HR][/HR]​Actually, your confusion is understandable.
It's possible to disconnect the frequency valve and run it as a basic CIS system, setting the mixture manually and letting it go at that. The problem with that is that it will be basically the same mixture at all RPM's at all loads.
When you have the full CIS-Lambda setup, you actually set the base mixture to be lean. The lambda controller then uses the frequency valve to enrich the mixture up to optimal. The lambda controller with full throttle enrichment will run the frequency valve at full rich when the full throttle switch is closed and the engine speed is over 4000 RPM's. So, you can run a richer mixture under those conditions with CIS-Lambda, and you won't have the rich idle and rich running off throttle that might foul plugs and cause other serious problems.
Normally, you set the base mixture so that the frequency valve is operating at 50% under most normal, light load conditions. If you're running boost, or need more enrichment for some other reason, you can actually set the base mixture richer, shooting for 30% or so duty cycle on the frequency valve at idle and under light loads. This will give the lambda controller more room to enrich the mixture, and it will increase the amount of "boost enrichment" you get from the full throttle enrichment circuit. Another option for forced induction engines is to put a pressure sensitive switch in the intake and use it to short out the thermo switch. That will also put the controller into open loop mode and run the frequency valve at 80%. On the older units, you can hook up a full throttle switch this way and get similar results to the later system with the full throttle switch.
Finally, I know that the "frequency valve" is a single injector from a pulsed system. Does anybody know the specs on this particular injector? Has anybody tried a higher capacity injector, or running two injectors in parallel on the frequency valve wiring? Obviously, this would have to be done very carefully, paying attention to the impedance rating of the stock injector and matching the pair of injectors to that as closely as possible.


----------



## tyrone27 (Sep 7, 2001)

*Re: fuel limit on CIS (Racer_X)*

What CIS injectors are the best to use?


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Racer_X)*

quote:[HR][/HR]Finally, I know that the "frequency valve" is a single injector from a pulsed system. Does anybody know the specs on this particular injector? Has anybody tried a higher capacity injector, or running two injectors in parallel on the frequency valve wiring? Obviously, this would have to be done very carefully, paying attention to the impedance rating of the stock injector and matching the pair of injectors to that as closely as possible.[HR][/HR]​From what I remember, it's just a low impedance Bosch injector. Peter is setting his system up with dual freq valves in parallel. One is controlled by the stock computer, the other is controlled by an EIC. I was thinking of doing the same when the time comes. You just have to make sure your EIC can handle that injector specifically. Usually it'll just take a resistor pack inline to make sure it'll operate fine.
There was a good discussion over in the Mk1 forum about CIS injectors a week or so ago. The consensus was to use MB 190E injectors as replacements when necessary. Similar, slightly higher, flow rate and an exact drop in.


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (need_a_VR6)*

hi folks,
I have a wide band a/f meter on order - should come in next week. Looking forward to seeing if the 240t unit goes lean up top...I'll post results....
regards,
Peter T.


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Peter Tong)*

What unit did you get Peter? Can you share the price? I know they're typically NOT CHEAP to say the least. 
How much boost are you running these days? Supposedly the Volvo CIS is good for up to 12psi on a 2.1 8v, I wonder how that will translate to a VW 2liter 8v. I'd think it would be pretty similar, but who knows....


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (Andrew Stauffer)*

quote:[HR][/HR]What unit did you get Peter? Can you share the price? I know they're typically NOT CHEAP to say the least. 
How much boost are you running these days? Supposedly the Volvo CIS is good for up to 12psi on a 2.1 8v, I wonder how that will translate to a VW 2liter 8v. I'd think it would be pretty similar, but who knows.... [HR][/HR]​I went with a lambdaboy unit (www.lambdaboy.com). It uses an NTK Honda VX sensor as opposed to a Bosch LSM-11 sensor. Its $485... I normally see 5 psi (6 if its cold outside) and that is just fine, but that is without flooring it. I've refrained from putting the pedal to the floor due to the stock pistons. A friend of mine did so and the gauge showed 10psi, but the motor didn't like that too much - the knock sensor was pulling timing out like crazy... thats about what I calculated based on pulley size... this is a relatively large pulley. Anyways, the wide bands are $$$ but in my mind the only way to get the thing properly road tuned is to have this tool... no point have VSAM-PRO to adjust things unless I can get the a/f ratios correct...
Cooling system seems to be working pretty well with a 20-40F drop through the smaller radiator alone. I noticed coolant temps drop noticeably (as did ping) when I finally plumbed up two of the 16v Scirocco belows to the airbox to get cool air...
regards,
Peter T.


----------



## psi (Oct 18, 2001)

*Re: fuel limit on CIS (Peter Tong)*

Good to see some of you people using the CIS system http://****************.com/smile/emthup.gif Keep up the good work guys http://****************.com/smile/emthup.gif


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Peter Tong)*

quote:[HR][/HR]I noticed coolant temps drop noticeably (as did ping) when I finally plumbed up two of the 16v Scirocco belows to the airbox to get cool air...
[HR][/HR]​Note to self, get another one of those







I lost my last one because it wasn't hooked up securely enough. The next one I'm screwing in


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (need_a_VR6)*

Hi CIS folks,
Got the wide band A/F meter today. Should be interesting to see where the 240 tubo injection starts to go lean...long term plan is to mount the wide band sensor in place of the existing stock heated sensor, and drill a hole in the downpipe collector for the stock sensor... The a/f control box has a simulated EGO output that I should be able to connect to the CIS lambda box in the meantime.
For the air intake - I have two Scirocco 16v bellows plumbed together to make a long induction pipe down into the drivers side wheel well. The plan is to get some mesh screen and mount the intake end down there. I don't want high pressure - just cold temps and ambient pressure.
Peter T.


----------



## kimosullivan (Aug 12, 2002)

*Re: fuel limit on CIS (Andrew Stauffer)*

Which CIS car made the most HP? I'm not sure, only VW calls it CIS. As far a Bosch K-Jetronic based systems go: Lamborghini used two 6 cyl units on their V-12 engines, I'd estimate 400 hp at least. Mercedes-Benz used K-Jet on their formula racing V-8 engines. 1000+ hp at 15k rpm and 5 bar?
Here's my question. Which comes first: mixture control unit or turbocharger? I'm trying to convert a 1970 VW aircooled to turbo FI, and K-Jetronic seems to be the least invasive (no map, flywheel, throttle, coolant, etc sensors or electronics). If the air-flow sensor is upstream of the compressor, do I need to use a turbo system control pressure regulator? The way I see it, the air flap always sees ambient air flowing thru it on the way to the turbo, so I shouldn't need to mess with the control pressure due to different pressure flow thru the sensor. Any comments? The only complication I can for see is the blow-off-valve needs to be routed back into the intake since that air has already been metered.
BTW, does any one have a system control pressure regulator for sale cheap?


----------



## JettaRed (Aug 14, 2000)

*Re: fuel limit on CIS (tyrone27)*

Tyrone,
You should talk to Steve Nomm, the shop foreman at Russel Automotive in Catonsville (on Route 40). His Scirocco puts 392 hp to the wheels.
(I haven't read this whole thread, so I don't know where it went. But I saw you were in Balti and thought you'd be close enough to talk to Steve. He's pretty busy during the day, so it may be hard to reach him.)


[Modified by JettaRed, 5:44 AM 8-13-2002]


----------



## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (kimosullivan)*

You are right on the fuel system has already metered the air and the fuel mixture would be the same if it is under boost or not. The reason to add more fuel under boost is to help control detonation. The additional fuel helps cool the air more and helps slow the speed of combustion. If you want to run at a leaner mixture then go ahead, but if things start to heat up because you are on the ragged edge see Fast Bunny for pistons.


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (kimosullivan)*

quote:[HR][/HR]Here's my question. Which comes first: mixture control unit or turbocharger? [HR][/HR]​Good question, I *think* it wouldn't matter as the mix unit doesn't care about pressure, just flow. Just like a MAF doesn't care if it sees -22mmhg or 5psi as long as it's within range. 
I think Peter was forcing air into his Autorotor setup for at least a little while, so he might be good to get some more info from.
One thing with Kjet though, the filter is part of the airbox/fuel distro assy. You would have to run a filter before the turbo then make sure the "airbox" is FULLY sealed as it'll be seeing boost now.


----------



## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (need_a_VR6)*

Paul, the air inlet side of the CIS flowmeter needs to see ambient atmospheric pressure. What that effectively means is that you have to suck through the meter always...
best regards,
Peter T


----------



## TURBOCADDY (Jan 17, 2002)

*Re: fuel limit on CIS (Peter Tong)*

I have been talking with some people around here and found out the cascade motorsport rally rabbit was running a stock bottom end g60 callaway turbo kit with cis and aquamist water injection at 25 psi making over 300 hp. The water injection allowed them to crank up the boost fight detionation and cool intake temps making more power
maybe the ultimate solution to cis and boost fueling problems


----------



## kimosullivan (Aug 12, 2002)

*Re: fuel limit on CIS (Butcher)*

I have to vent first. NEVER TAKE YOUR CAR TO MIDAS. THEY ROYALLY SUCK! I just got done replacing a wheel cylinder they installed after the bleeder valve threads striped out of it. Also, they didn't torque the axle nuts enough and used the wrong size cotter pin when they put it back together the first time. Could have had a wheel fall off, but the wheel bearing noises clued us in.
Now back to our topic. Ok, now I understand why most people here want to run rich under boost. I'm working on the non-electronic version, so your mileage may vary.







If the turbo warm up regulator isn't juicing it enough for you how about adding a fuel circuit to bypass it when under boost resulting in reduced control pressure and more fuel flow? This would allow the barrel in the distributor to rise more since the control pressure is less. It's kinda ghetto, but might be possible. Seems to me the professional way would be to get an air-flow sensor that is steeper at the big end of the cone. This would allow the barrel to rise more since the air is pushing harder to get thru the skinnier opening.
As far as detonation control goes, I'm thinking about trying to swipe the Motronic ignition system from an A3. I was talking to a guy at the drag races last Sunday with an A3 Golf. He's got an aftermarket injection computer, but left the Bosch ignition intact. The pro racers that he has talked to said there is no aftermarket ignition better. I've looked around, and I haven't seen any knock detection aftermarket systems.


----------



## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (kimosullivan)*

Peter, thanks for the clarification. http://****************.com/smile/emthup.gif (but is there a *reason* it has to be that way?)
quote:[HR][/HR]If the turbo warm up regulator isn't juicing it enough for you how about adding a fuel circuit to bypass it when under boost resulting in reduced control pressure and more fuel flow? This would allow the barrel in the distributor to rise more since the control pressure is less. It's kinda ghetto, but might be possible. [HR][/HR]​There also might be a pin (*I* haven't found it) on the ECU that you can ground out to get the frequency valve to open more. Does the same thing. 
quote:[HR][/HR]Seems to me the professional way would be to get an air-flow sensor that is steeper at the big end of the cone. This would allow the barrel to rise more since the air is pushing harder to get thru the skinnier opening.[HR][/HR]​I have yet to find a 4cyl fuel dizzy that's THAT much different from the Rabbit ones, other than the 240t dizzy. 
quote:[HR][/HR]As far as detonation control goes, I'm thinking about trying to swipe the Motronic ignition system from an A3. I was talking to a guy at the drag races last Sunday with an A3 Golf. He's got an aftermarket injection computer, but left the Bosch ignition intact. The pro racers that he has talked to said there is no aftermarket ignition better. I've looked around, and I haven't seen any knock detection aftermarket systems.[HR][/HR]​http://www.jandssafeguard.com/ there's one, but the Bosch stuff is supposedly pretty darned good.


[Modified by need_a_VR6, 8:08 AM 8-14-2002]


----------



## gearhead455 (Oct 30, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

quote:[HR][/HR]There also might be a pin (*I* haven't found it) on the ECU that you can ground out to get the frequency valve to open more. Does the same thing. 
[HR][/HR]​I have grounded out the frequency valve 100% ON with a relay driven by the WOT switch... You can damn near flood the engine out with fuel at WOT if you wish.








If fuel is what you want, fuel you will get!










[Modified by gearhead455, 5:39 PM 8-14-2002]


----------



## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

This applies to the K-jet box with part number:
0 280 800 060 (BOSCH)
035 906 263F (VW)
I would go by the Bosch PN as the VW one may change even if the box doesn't. 
I opened up my box and identified pins which could potentially trigger other PWM modes.
I picked the pins by locating the IC that connects to the O2 sensor pin and the FT switch pin, and then traced all of the other pins from that IC. 
Again, these are just guesses, and aren't tested. If anyone wants to test it, look for pins in your harness - if there is a pin already there, then it's probably used for something else.
Anyway, here they are:
----------------
CIS possible open loop pin connections 89 cabriolet
0280 800 060 (BOSCH)
035 906 263F (VW)

pin 7
pin 11
Pin 6 (?? need to add resistor R531 and cap c507 inside control unit)
pin 14
pin 9
pin 2

------------

I have also made a circuit which lets you adjust the duty cycle (from about 30%-90%) for "full throttle" open loop mode. I've probably got $20 in parts (Radio Shack prices) in it. So far it seems to work pretty well. If anyone is interested in it, I can give more info.
-Steve


----------



## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Stephen Webb)*

quote:[HR][/HR]
----------------
pin 7
pin 11
Pin 6 (?? need to add resistor R531 and cap c507 inside control unit)
pin 14
pin 9
pin 2
------------
[HR][/HR]​I should add that this list is a "raw" list of the pins. Some of them are already used, and have definite function.
Pin 7 is the full throttle / cold acceleration enrichment switch
Pin 2 is the O2 sensor signal input.
That leaves 
11, 14, and 9 to play with. (and 6 if you are adventurous)
My personal guess is that pins 11 and 9 are the ones to mess with.


----------



## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Stephen Webb)*

quote:[HR][/HR]
My personal guess is that pins 11 and 9 are the ones to mess with.
[HR][/HR]​I did a bit more research.
People may recall the "Terminal 11 trick" that the Volvo 240 turbo guys use to get a higher (90%?) duty cycle. I'm not sure who figured that out or how, but most people seem to agree that it works (I've never tried it myself--I don't have a turbo Volvo 240).
I happen to have the wiring diagram for a Volvo 240 turbo, and I compared it with the wiring diagram for my 89 cabriolet.
NOTE: The Bentley manual (Cab, Scirocco incl 16v. 85-93, copyright 1992) is WRONG on the pin numbers for a few of the pins in the "89 cabriolet electronic engine controls" diagram. 
In particular: 
Pin 33 is actually pin 31
Pin 21 is actually pin 15
Pin 17 is labelled as being BR/W and it should be BL/W
These are just my observations with my car, and I could have made a mistake. Double check yours.
----------
OK, on with the goods.
People have speculated that there is a "terminal 11" trick available for VWs, too, but we just weren't sure which pin we actually should ground. (is it 11, the same as on the Volvos, or some other pin alltoghether?)
I compared the schematics from a Volvo turbo to my '89 cabriolet, and they agree pin for pin on every account. 
Pin 2 is the O2 sensor input, pin 7 is the FT (or hobbs in the case of the volvo), pin 15 is the frequency valve, etc, etc.
There are no guarantees, to be sure, but the fact that EVERY pin matches, and that I identified pin 11 as a potential pin to try, I think the odds that you can ground pin 11 and get 90% (or whatever it is) duty cycle are pretty high. (Make sure you hae the right computer!)
I'm not sure what pin 9 does. It's got a pretty big resistor inline with it (200k), so it probably wouldn't hurt to play with it, but it doesn't look like pin 7 and pin 11 do, so I don't know what it might do. 
Pin 14 is still a possibility, too.
-Steve


[Modified by Stephen Webb, 12:44 PM 8-14-2002]


----------



## Andrew Stauffer (Oct 2, 2000)

*Re: fuel limit on CIS (Stephen Webb)*

Very nice work there, Steve. 
So, if we replace the full throttle switch that gives pin 7 it's signal*(ala VW) with a Hobbs switch, ala Volvo, we have boost enrichment instead of full throttle enrichment, albeit a conservative level of enrichment. Taking this a step further, we could than add another hobbs switch, set to trigger at higher boost than the pin 7 hobbs switch mentioned in the previous sentence. If this 2nd hobbs switch would then trigger pin 11 we would get the fatter enrichement at a higher boost level. IE, sequential 2 step boost enrichment out of our common VW CIS lambda fuel injection. Very cool. 
My question now: Is the VW set up, combined with the pin 11 trick, good for 200hp? Or would we still need to bring the volvo 240T fuel dist and flow bowl over? 
To ask it another way, what's the hp limit of VW CIS lambda utilizing the pin 11 trick? I'm not sure anyone here knows the answer at this point in time, but it may, *may* raise the bar.


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Andrew Stauffer)*

quote:[HR][/HR]So, if we replace the full throttle switch that gives pin 7 it's signal*(ala VW) with a Hobbs switch, ala Volvo, we have boost enrichment instead of full throttle enrichment, albeit a conservative level of enrichment. Taking this a step further, we could than add another hobbs switch, set to trigger at higher boost than the pin 7 hobbs switch mentioned in the previous sentence. If this 2nd hobbs switch would then trigger pin 11 we would get the fatter enrichement at a higher boost level. IE, sequential 2 step boost enrichment out of our common VW CIS lambda fuel injection. Very cool. 
[HR][/HR]​This is assuming that pin 11 *really* does the same thing on a VW box as it does on the Volvo box. And it also assumes that pin 11 has "higher priority" than pin 7 (which it probably does...)
quote:[HR][/HR]
My question now: Is the VW set up, combined with the pin 11 trick, good for 200hp? Or would we still need to bring the volvo 240T fuel dist and flow bowl over? 
To ask it another way, what's the hp limit of VW CIS lambda utilizing the pin 11 trick? I'm not sure anyone here knows the answer at this point in time, but it may, *may* raise the bar. [HR][/HR]​Yes, that is a good question. I don't know -- maybe someone can performa test to figure it out.
It may increase the total fuel flow (maybe even to 200 HP worth), but it may not be calibrated properly. In other words you might get 200 hp worth of fuel for 170 hp worth of airflow. Someone (about 5 posts up) said that they grounded the frequency valve (essentially 100% duty cycle) and got way too much extra fuel. I think the real way to deal with it is with controllable duty cycle. If 90% is too much, and 60% is too little, it's going to take some work to get it to run right. 
Some of the volvo folks complain that 90% duty cycle is just too much, and their car runs so rich it stumbles.


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## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (need_a_VR6)*

quote:[HR][/HR]Peter, thanks for the clarification. http://****************.com/smile/emthup.gif (but is there a *reason* it has to be that way?)
[HR][/HR]​Paul, the CIS flowmeter is setup much like a rotameter but with a counterbalance to take gravity out (and the sensor plate is the float) and act as a damper. The warm control pressure substitutes for gravity in the rotameter and forces the sensor plate to resist air flow such that the proper a/f ratio is maintained. Piston depression causes the flow (obviously). Since Bosch knew the pressure on the intake side of the flowmeter would be ambient and at a certain density, Bosch set the proper counterforce to resist it. If you change the density (as you mentioned) then you have to change the counterforce (control pressure) to compensate. 
If you put the flowmeter upstream of the throttle but downstream the turbo/compressor/blower you'd need to be varying the counterforce in relation to the pressure changes to ensure a linear relationship - CIS doesn't do that - therefore it wouldn't work... air density does vary due to altitude - hence the altitude compensating warm up regulators...
Just my $.02 worth...
Peter T.



[Modified by Peter Tong, 7:40 PM 8-14-2002]


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Peter Tong)*

Peter, thanks again.. got it now








So, who wants to ground Pin11?


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## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

Just to let you know that MB also has the same pin outs for the CIS ECU. Shorting out #7 will also set the frequency valve to 60%. Sorry to say MB does not use #11 at all. Since the CIS ECU is not a very complicated control unit [to todays standards] maybe we should attempt to use the Volvo ECU since all the pins are the same. MB shorts out #7 in the cold running mode so the Lambda stays at a fixed signal and the rest of the fuel adjustment is done with the warm up reg. I am certain [but not positive] that everyone else does too. Might be a little easier than just shorting out an ECU that may burn it up.


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Butcher)*

quote:[HR][/HR]Just to let you know that MB also has the same pin outs for the CIS ECU. Shorting out #7 will also set the frequency valve to 60%. Sorry to say MB does not use #11 at all. [HR][/HR]​I'm not sure what you mean by "doesn't use pin 11 at all", but just to clarify:
I don't think Volvo uses pin 11 from the factory for anything (at least not based on the wiring diagrams that I have) I believe you have to add a "pin" to the wiring harness to gain access to pin 11. You definitely would have to on the VW wiring harness (for my car, at least). 
I agree that it's a bit dangerous to run around grounding pins on the ECU, and maybe it would be a safer bet to get a Volvo ECU that is "known" to work. How easy are they to get? (Volvo ECUs) I can get a spare for my car for about $30, but I'm not sure how easy / cheap it is to find the Volvo 240 turbo ECU. (maybe the same as non-turbo CIS Volvos? Not sure)
Since my car isn't running right now anyway, and since I am saying I'm confident that pin 11 is the correct pin, I'll "put my money where my mouth is" and go try it tonight. I'll let you guys know the results.
-Steve


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Stephen Webb)*

quote:[HR][/HR]Since my car isn't running right now anyway, and since I am saying I'm confident that pin 11 is the correct pin, I'll "put my money where my mouth is" and go try it tonight. I'll let you guys know the results.
-Steve[HR][/HR]​I tried to start another thread. This one was getting long. Maybe I should have just stuck with this thread.
At any rate, here's the scoop. I grounded pin 11, and I got about 90% duty cycle. 
-Steve


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## Peter Tong (Jun 17, 1999)

*Re: fuel limit on CIS (Peter Tong)*

Hi Folks,
Got the wideband on the car the other day (fed the OXS box simulated EGO signal from the wideband meter) and had the chance to do a little testing. I don't have the unit hooked into the laptop to get more accurate values...so am going by the units indicator leds....which are ~1.3 a/f units apart..
Idle - a/f ratio bounces between 14.7:1 and 17.4:1. 
Part throttle - 14.7:1 and 16.0:1 during cruising conditions (cycles a narrower range).
Full throttle - 14.7 until transition into 1-2 psi boost range - 13.0 to 13.9:1. 3-6 psi and the a/f drops into the 12.x:1 range. This was with the VSAM set to cycle the secondary frequency valve at 10% and with a pressure switch mounted on the intake manifold to trigger the stock 65% enrichment...
I noticed that testing during the evening vs the day added about 1 unit (ie 13.0 to 14.0) to the mixture. Ie things became more lean during the evening. Denser air? but it was the case... I am going to tune the CIS for 12.x to 1 through the WOT rev range...and set the pressure switch to switch on at low vacuum instead of boost...
regards,
Peter Tong


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## need_a_VR6 (May 19, 1999)

*Re: fuel limit on CIS (Peter Tong)*

Peter, it really looks like we got the same results for both idle and part throttle. I've noticed since my post that part throttle cruising is a nice tight loop as well. 
At WOT though on my NA motor, I go to 13:1 as soon as I go to WOT at low RPM and 12.5:1 any higher. I do run about ~.5 leaner on cool days and nights though. CIS has no compensation for density it seems, maybe taking the plug off the atmo port on the WUR would help.


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## tyrone27 (Sep 7, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

bump


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## G60RRADO (Nov 30, 2000)

*Re: fuel limit on CIS (tyrone27)*

http://****************.com/smile/emthup.gif good reading http://****************.com/smile/emthup.gif


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (psi)*

quote:[HR][/HR]I believe the injectors are the same(Volvo/VW),so that won't do anything.To make this work you need the whole 240T fuel dist.There are some goons here that I talked into running this unit,and they all seem to have good results(although they are chicken to turn up the boost







).[HR][/HR]​Hey, wait a minute. I'm one of those goons. 
What do you consider "turning up the boost". I'm still waiting on that knock sensor ignition, I'll crank the boost once I have that on there.
I'm building a new motor, and I plan on going to 15 PSI. Is that good enough for you?







If yo want 18 PSI, maybe I will just have to do that.
-Steve
(how high did you turn the boost up?)


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## Butcher (Jan 31, 2001)

*Re: fuel limit on CIS (need_a_VR6)*

I have been thinking about this pin 11 thing and it would seem to me that you would need an RPM switch and a Boost switch in order for it to work better. My reasoning is that at 20 psi boost at 3000 the fuel dist. will most likely have enough fuel delivery but 20 psi at 7000 it will not. Same idea with the RPM [7000 rpm with no boost you will not need the extra fuel that pin 11 can give you]. What you would need to find out is when the fuel dist. is maxed out and then shorting out the pin. Seeing max boost at a certain RPM should be the basic information needed [sure you can use outside temps and everything else but this is CIS]. 
I was also wondering if you could use a air flow sensor housing from a CIS-E system that has the air flow sensor potentiometer on the side. With a 0-5v signal
[higher voltage the higher the flow] you could use some fancy transistors and what not to trigger pin 11 with that signal.


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## Stephen Webb (Apr 12, 2001)

*Re: fuel limit on CIS (Butcher)*

Yeah, I agree that using the terminal 11 deal is probably too much in most cases, and would only need to be triggered as you approach the limit of the FD. At that point, though, I start to get nervous (running near the limit of the FD) because in the tests which I have run, I noticed more variation in the fuel delivery from cylinder to cylinder when the plate was at full lift. 
Just a thought.
-Steve


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## ADE080 (Jul 30, 2002)

*Hi Peter*

Hi Peter.. its Bill Lumberg here..
im gonna have to go ahead and get you to hand in those Tps reports on my desk by friday.. if you could do that, that would be Great!








Just kiddin.. im going to try a 6cyl benz setup, i'll keep you guys posted!


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## adidas_mc (Apr 26, 2003)

*Re: Hi Peter (ADE080)*

how much would a setup consisting of volvo 240t duel dizzy, audi wur, a nice extra injector controller (for one or 2 extra injectors)? im aimng for 200whp on a 1.8 16v with stacked gaskets. would this setup cost more than converting to digi1?


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## ragman (Apr 11, 2002)

*Re: Hi Peter (adidas_mc)*

Wow, I remember reading this post when it was first started (August 02?). Good stuff! This was one of the many posts that got me through my turbo project. http://****************.com/smile/emthup.gif


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## adidas_mc (Apr 26, 2003)

*Re: Hi Peter (adidas_mc)*

so does anyone have a ballpark figure on my junkyard setup? volvo240t dizzy, boost sensitive wur, saab t-3, small intercooler, stacked gaskets, stock 1.8 16v internals ~8psi ~175whp...$?


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## Peter Tong (Jun 17, 1999)

*Re: Hi Peter (adidas_mc)*

ok, I didnt get my tps report in by friday, but hows today?








Wow - talk about being resurrected from the dead! I just got my car back going for the summer (it was down for test fitting my Lysholm parts)... the thing runs better than ever...


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## ErosNJ (Oct 21, 2002)

*Ok with fuel... how about timing ?*

I have read all of the posts on fuel limits on the CIS. My engine 
needs to lower the compression and I will try to get as much out of my KR 1.8 16V. My goal is anything close to 200 bhp. 
I will manage the fuel until I go MEgaSquirt, but what do you CIS guys do with SPark?


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## Peter Tong (Jun 17, 1999)

*Re: Ok with fuel... how about timing ? (ErosNJ)*

I use a Crane Hi-6...but the stock ignition is quite good...


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## ErosNJ (Oct 21, 2002)

*Re: Ok with fuel... how about timing ? (Peter Tong)*

I mean with the ignition advance/retard.
Do you leave it as is? Do you retard a few degrees ?


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## Peter Tong (Jun 17, 1999)

*Re: Ok with fuel... how about timing ? (ErosNJ)*

You don't want to just retard a few degrees. That will kill naturally aspirated torque as best timing for torque will be prior to when the spark actually goes off reducing applied work to the crank. You want to retard only when needed - under boost. Note - the BTM, Crane Hi-6 setups work well they retard the stock curve a specified amount per lb of boost. This is a rough approach but works. The downside to them is that they start retard at the vacuum/boost crossover point when lots of motors don't need retard until boost has reached a threshold point.
There are other compromises too - in short they modify the stock curve, and don't necessarily provide the optimal timing curve during boost.
hope this helps,
Peter T.


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## ErosNJ (Oct 21, 2002)

*Re: Ok with fuel... how about timing ? (Peter Tong)*

Check this story out . http://www.ffp-motorsport.com/...x.php
He made a Distributor with a retard at boost! 
Has anyone tryed this? With Boost levels of about 5-7 psi and good intercooling can you stay with stock distributor?







Or will it be ping heaven


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## kimosullivan (Aug 12, 2002)

*Re: Ok with fuel... how about timing ? (Peter Tong)*

While this thread is active, I might as well hijack it ask if anyone has a blown up CIS head. I want one to cut in half so I can get the cross section of the injector mounting holes. This is part of my effort to put CIS on an air-cooled motor. A drafting of the cross section would also work, but I doubt anyone has that handy.


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## vdubspeed (Jul 19, 2002)

*Re: Ok with fuel... how about timing ? (kimosullivan)*

I know there is a company that puts CIS on VW motors but I can't remember their name or URL. IIRC they had it installed on a van because of all the extra room engine bay. My friend in Panama City is doing the same thing. Good luck
Jason


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## ADE080 (Jul 30, 2002)

*Re: Ok with fuel... how about timing ? (ErosNJ)*

Hey man.. buy the Msd boost timing master..
its simple and does the job...
i paid like $260us for it from Jegs...
good luck!!


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## theenico (Nov 12, 2003)

*Re: Ok with fuel... how about timing ? (ADE080)*

bump for anyone needing some '82 5000T fuel injection pieces. http://****************.com/smile/emthup.gif
Fuel distributor for an '82 (have one off an '86 MC code also) warm up regulator off the '82, injectors/lines, etc. Also have the complete engine with intake and exhaust manifolds from the '82 as well as everything from the MC code car needed to convert a 4000Q to '86 5000TQ specs.
IM me if anyone's interested


_Modified by theenico at 10:38 AM 8-16-2004_


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