# Dynoed the Turbo Audi Fox



## Longitudinal (Nov 13, 2004)

Finally got around to running the 8VT KE-Jetronic Audi Fox on a chassis dyno. Results were very positive for a first outing. When you see the graph, which I will attempt to post soon, you will see that I need to add some fuel in the mid range. Peaks were 204.5 WHP and 230.7 WTQ.
Also, at high RPM, I was extinguishing spark. I will be experimenting with plugs and gaps this week. I am open to suggestions. 
For my first turbo project, on eight valves and 1.8L, with 20-year-old equipment, I was very pleased!
Here's the dyno plot:










_Modified by Longitudinal at 9:26 AM 9-13-2005_


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## 2008cc (Apr 16, 2001)

*Re: Dynoed the Turbo Audi Fox (Longitudinal)*

sounds good. can you refresh us with your setup , and maybe some pics? keep it up. http://****************.com/smile/emthup.gif


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## iluvfastcarz (Mar 15, 2004)

*Re: Dynoed the Turbo Audi Fox (2008cc)*

Holy crap batman, did you expect any less, that thing pulls like there's no tomorrow. Congrats, now how bout you make it a quattro







. You were planning on puttting a bigger turbo on it right? Won't that just make the wheels loose grip throughout third gear?


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## Longitudinal (Nov 13, 2004)

*Re: Dynoed the Turbo Audi Fox (2008cc)*


_Quote, originally posted by *2008cc* »_sounds good. can you refresh us with your setup , and maybe some pics? keep it up. http://****************.com/smile/emthup.gif 

Link here to the thread in the VW Fox forum.
Here is the description from a while back, posted in the FI forum:
Very little about this car has been posted on the internet, so most here don't know about it.
Car: '77 Audi Fox 2-door, Reseda Green
Engine: 1.85L made from 1.7L crank, Audi turbo rods and 82.5mm JE pistons, machined out for 7.2:1 CR. Ported head, stainless valves, (for now) Autotech 266 cam, TT pulley, ABA steel head gasket, ARP studs
Turbo system: K24 turbo with 20V compressor and 5K TD turbine and air cooled center, 5K TD exhaust manifold, front mounted 18*8.75*2.75 Griffin intercooler, home-made plumbing, pierburg BOV
Fuel and ignition: KE Jetronic from MB V8, VW CIS-E harness and ECU with knock-sensing ignition and turbo coil. For the moment, ignition is totally under the control of the knock ECU. I might eventually change the ignition if somebody convinces me this setup is not effective.
Suspension and brakes: SRS coil overs with 300/250 springs, Bilstein struts (Rabbit rears, 4K fronts,) 9.4" vented front brakes with Mintex C-Tech "Road Rally" pads and power slots, 8.9" disk rears with Minted Redbox pads.
Wheels and tires: Ronal R8 15*6 and Potenza S-03 Pole Positions.
So far, the car is running very well. Under boost, mixture is pretty stsble around 13-13.5:1, which is a little bit lean and requires a bit more adjustment. Boost is at 14 PSI, limited by stock wastegate. Plans for the immediate future are a boost controller, 20 PSI boost and some more fuel.
The MB fuel distributor is working very well so far, but it requires WAY more space than the four cylinder units. I had to cut a huge hole in the right side fender well and build a stainless steel insert to allow space. As is, the far wall of the insert is in contact with the connector for the RF marker lamp. Other than fitment, the fuel distributor is functioning very well, even with a dead potentiometer. Idle was WAY too fat and required lots of leaning out to get it right. So far, tuning for power has been uneventful.
The extra four injectors are mounted in welded-in mounts in the intake manifold runners.
The fuel system is a bit unconventional, and many hardcore CIS guys might say it is copping out to use an extra row of injectors to get the required amont of fuel. At the current output, I could fuel the engine on four injectors and an updraft four cylinder FD. But I intend to do what it takes to get this car to 300 HP, which is well beyond the capacity of four normal CIS injectors. 
__________________________________-
Here are pics from that thread:


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## Longitudinal (Nov 13, 2004)

*Re: Dynoed the Turbo Audi Fox (iluvfastcarz)*


_Quote, originally posted by *iluvfastcarz* »_Holy crap batman, did you expect any less, that thing pulls like there's no tomorrow. 

It's a lot faster, now, Lido. The next step is to stop the boost-related misfire, then have fun. I really don't think a larger turbo would be very useful.


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## firestorm13666 (Jun 17, 2004)

Are you running a Diesel head or am i just seeing things?


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## PADILLA (Sep 26, 2000)

*Re: (firestorm13666)*


_Quote, originally posted by *firestorm13666* »_Are you running a Diesel head or am i just seeing things?

Looks like he's running 8 injectors, off a Benz V8 cis fuel dist. maybe?


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## g60vwr (Apr 9, 2000)

*Re: Dynoed the Turbo Audi Fox (Longitudinal)*

I need to see more pics of that car-- it looks so clean- so original!
I love it!


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## rossmc1 (Feb 29, 2004)

*Re: Dynoed the Turbo Audi Fox (g60vwr)*

would really like to see a pic of your car if u dont mind(did asked u in your Fox post)cheers and awesome project (good to see something different)


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## liquidtension (Mar 25, 2004)

*Re: Dynoed the Turbo Audi Fox (rossmc1)*

huge props buddy


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## Gigante (Aug 22, 2001)

Nice setup. BTW, where can I find a valve cover like that?!


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## VR6-JettaIII (Jul 21, 2003)

*Re: (Gigante)*

it's a G60 valve cover. wicked nice when theyre polished http://****************.com/smile/emthup.gif


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## vw16vcabby (Sep 19, 2001)

cool setup, i like it. it is original.
only question is, how do u keep the car from loading up on uel at idle, low throttle situations? i would think that w/ 2 injectors per cylinder dumping fuel constantly, you woud be pretty rich until boost kicks in.
either way, i totally dig the car! havent seen an audi fox in a long time.


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## Andrew Stauffer (Oct 2, 2000)

*Re: (vw16vcabby)*

Bump, like Sailor(vw16vcabby) I'm curious to know how that benz fuel dist is managed. Great old school set up btw. The dyno #s are fantastic...


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## dohc (Sep 28, 2001)

*Re: (Andrew Stauffer)*

That's pretty much what I wanted to do, but with a 16V.
I decided not too because the ignition computer I have is being used for another project...but maybe just running the seperate KE ignition computer with knock control is enough?!?
I don't think it makes a difference what size engine you run. A 4cyl. idling at ~1000rpm will comsume about the same amount of air as an 8cyl idling at ~550rpm.
If I were to do this, I would have to buy all the diagnostic equipment for CIS. Another reason I shyed away from it was that new CIS parts are prohibitibly expensive, and used parts are hit and miss.
I wonder if there is any troubles with putting two injectors so close to each other in the same intake tract. The fuel particles from the upstream injectors would clump together with the lower injectors, but I guess not enough to really do any major harm. Mounting them further upstream would allow more time for atomization, at which point they can clump together anymore.
Did you mount the second row of injectors as far upstream as possible?


_Modified by dohc at 12:22 PM 9-13-2005_


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## Longitudinal (Nov 13, 2004)

*Re: (vw16vcabby)*


_Quote, originally posted by *vw16vcabby* »_only question is, how do u keep the car from loading up on uel at idle, low throttle situations? i would think that w/ 2 injectors per cylinder dumping fuel constantly, you woud be pretty rich until boost kicks in.

Actually, CIS is only metering out fuel acording to the amount of air consumed, not in any way based on the number of cylinders or number of injectors. You could probably run a Briggs engine on a 4-cylinder unit with all four injectors running and CIS-E would sort it out rather well.
This fuel system doesn't over-fuel anywhere. "Dumping" is not a fair word. This is a surprisingly accurate and sensitive fuel system, considering the age and technology cheaply available at the time. The only over-fueling issue it ever had was at idle, which was easily overcome with a couple CCW turns of the idle adjustment screw. Otherwise, it fired and ran flawlessly for the whole run-in period. It stayed nice and lean-ish just on factory adjustment. After run-in, I turned up the fuel and away I went. 
Here's the dyno plot:








As you see, I need more fuel at the moment. There's probably 10-20 HP just in getting the midrange fuel closer to 12:1. But first, I need a strong enough spark, or the extra fuel is bound to blow out my spark even worse than it is now.


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## Longitudinal (Nov 13, 2004)

*Re: Dynoed the Turbo Audi Fox (rossmc1)*


_Quote, originally posted by *rossmc1* »_would really like to see a pic of your car if u dont mind(did asked u in your Fox post)cheers and awesome project (good to see something different)


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## Peter Tong (Jun 17, 1999)

*Re: Dynoed the Turbo Audi Fox (Longitudinal)*

Can anyone say "SLEEPER"?! (aside from the big FMIC







but that blends in with the chrome







)


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## Longitudinal (Nov 13, 2004)

*Re: (dohc)*


_Quote, originally posted by *dohc* »_I wonder if there is any troubles with putting two injectors so close to each other in the same intake tract. The fuel particles from the upstream injectors would clump together with the lower injectors

Atomized fuel is atomized fuel. It doesn't matter what injector it came from, as long as each cylinder gets an equal share of it.

_Quote »_Mounting them further upstream would allow more time for atomization, at which point they can clump together anymore.

Time? What's time? Calculate the amount of time that fuel is actually just hanging around before it is sucked into the engine when the engine is turning as slow as 3KRPM. The fuel is atomized about as well as it will be nanoseconds after it is released from the injector. 

_Quote »_Did you mount the second row of injectors as far upstream as possible?

I mounted them as far downstream as possible. Mount them too high in the runners and you subject the fuel they deliver to 1) currents in the plenum and 2) reversion from the shutting valve blowing the fuel back into the plenum, where it can be sucked into another opening port. The net result of the former and the latter is to starve one cylinder and make another too rich.


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## dohc (Sep 28, 2001)

*Re: (Longitudinal)*


_Quote, originally posted by *Longitudinal* »_Atomized fuel is atomized fuel. It doesn't matter what injector it came from, as long as each cylinder gets an equal share of it.
Time? What's time? Calculate the amount of time that fuel is actually just hanging around before it is sucked into the engine when the engine is turning as slow as 3KRPM. The fuel is atomized about as well as it will be nanoseconds after it is released from the injector. 
I mounted them as far downstream as possible. Mount them too high in the runners and you subject the fuel they deliver to 1) currents in the plenum and 2) reversion from the shutting valve blowing the fuel back into the plenum, where it can be sucked into another opening port. The net result of the former and the latter is to starve one cylinder and make another too rich.

Well, I have to agree and disagree with some of what you said, but your system works, so thats all that matters, I'm not trying to be a smart asz or a ****.
Yes it does take time for fuel to atomize, no injector releases atomized fuel, they release fuel droplets, the smaller the better, but the fuel still has to atomize/vapourize before it can be burned. In order to do this it still has to draw in heat from the intake charge (thats why a hotter motor runs more efficiently). How much fuel is atomized depends on temp. and time. Time depends on the length of the intake tract, rpm and the area ratio of intake tract area to bore area.
There are currents in the plenum, and if you mount the injectors too close to the opening, some fuel will be pulled out.
CIS is a little like batch fire, the injectors fire when they are not needed. You'd think that the this would cause the fuel to leave the port it was released in and move a cylinder that is on an intake stroke, but that is not the case.
During an intake stroke, the air/fuel charge is moving towards the open intake valve, when the valve shuts, the charge compresses (the charge has momentum) and creates a highpressure zone in the intake tract. The high pressure area near the valve reverses and moves towards the low pressure zone near the intake tract opening.
When it reaches the much larger volume of the plenum, it refracts back into the intake tract and repeats this process until the intake valve opens again. Its effectively a sound wave.
The atomized fuel, and fuel particles move with the sound wave. The fuel never leaves the intake tract (though in reality a small amount of it does, as fuel atoms and droplets are heavier then air).
http://www.jenvey.co.uk/
Read through the FAQ page if you don't believe me.
Though most of this is theory, it doesn't say what you are doing won't work...its just something to consider.
Where did you find your MB fuel dist, I had a hard time finding one for a resonable price. I ended up going with a Saab 900T dist with the adaptable frequency control valve module.


_Modified by dohc at 8:39 PM 9-13-2005_


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## BUNNYLOVE (Jul 28, 2000)

*Re: (Longitudinal)*

I never even seen one of these cars in person, very cool. I'm impressed.


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## vw16vcabby (Sep 19, 2001)

thank you for answering my question. looks like i know where the benz fuel distributor and lines sitting on a motor at work will disappear to...
also, i may have some audi fox parts at work, if i do, ill let u know if interested.


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## rossmc1 (Feb 29, 2004)

*Re: (vw16vcabby)*

Top car,thanx for pics
Do u know if this was ever released in UK i know there was Audi 80's 4dr but i have never seen a 2dr 80 
R all Foxes 2dr or r there 4dr also


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## joevwfox (Feb 20, 2007)

*Re: (Longitudinal)*

Hey Longitudinal, Im working on a similar project(Im pretty sure you have posted on it) but when you run a MB dizzy, do you not need to use the Audi turbo WUR? Or are you using the WUR from the MB? I am guessing that you are using the 1.6L block it came with....where does your oil feed line come from, did you use a port on top of the filter? Thanks 
http://forums.vwvortex.com/zerothread?id=3087286
By the way.. Those are some sick power numbers, very nice build


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## iluvfastcarz (Mar 15, 2004)

*Re: (joevwfox)*

Holy snaps, back from the dead. The MB fuel distributor is a CIS-E system therefore not requiring a WUR. http://****************.com/smile/emthup.gif IM Longitudinal for more specific details.


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## nap51dcrow (Apr 11, 2005)

so the mb fuel dizzy is off of what style car?


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## Issam Abed (Feb 12, 2004)

*Re: (nap51dcrow)*


_Quote, originally posted by *nap51dcrow* »_so the mb fuel dizzy is off of what style car? 

SL450 ...anything V8 really with CIS injection.


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## nap51dcrow (Apr 11, 2005)

thats kinda what i figured but i just wanted to ask. thanks, and can anyone explain the reason why a WUR is not needed?


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## Fox-N-It (Jul 23, 2003)

Its CIS-E which never had a WUR since it has some electronic control for cold start.


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## nap51dcrow (Apr 11, 2005)

ah, sorry i am still learning about CIS, but if i used that fuel dizzy on my 84 GLI would i need a WUR?


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## joevwfox (Feb 20, 2007)

*Re: (nap51dcrow)*

No you would not use a WUR if you put that into your car. But you would need to install some other things, to make it work proper (ECU, O2 sensor etc.) http://****************.com/smile/emthup.gif 


_Modified by joevwfox at 4:55 PM 12-3-2007_


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## TBT-Syncro (Apr 28, 2001)

*Re: Dynoed the Turbo Audi Fox (Longitudinal)*

gratz. those are great numbers for that setup.


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## Longitudinal (Nov 13, 2004)

*Re: (joevwfox)*


_Quote, originally posted by *joevwfox* »_I am guessing that you are using the 1.6L block it came with....where does your oil feed line come from, did you use a port on top of the filter?

Specs on the engine are up top, but it's a 1.8L using 1.7L crank and MC1 rods and pistons. I drilled and tapped a hole in the filter flange for oil supply. It all worked very well. Engine is in another car and taking regular abuse. 
My Audi Fox is apart for some minor changes. It should emerge again in a year and a half or so.


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## ziddey (Apr 16, 2006)

*Re: (Longitudinal)*

Forgive me for this thread revival. This is just too inspirational.
I know it's said that cis setups should be able to handle 160hp at least. But where is the limit roughly? I'm looking to do an aba16vt with a k24 turbo (hopefully all acquired from local junkyards). I'm planning on running cis-e, adding the knock box from a mk2 gli/gti.
Anyone actually found the limits of the stock vw cis-e fd?


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## EL DRIFTO (Jul 11, 2004)

*Re: (ziddey)*

one limit to the vw cis-e is the funnel plate is all the way to the top, out of metering ability, somewhere around 200 hp


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