# rev limiter



## nwvwgli (Aug 18, 2007)

Is there any way to raise the rev limiter or trick it to rev further this is what im working with 
86 jetta gli cise
aba botom end
jh head 290 cam hd spring decked .080 with tt adjustable cam gear all the way advanced cause the decking
autotech fuel enrichment maxed
9a trans
motor pulls hard till rev limit aka 6500 way too low its getting old
also would my car benifit from a knock sensor bushing this is my first build with cise oh ya my car idles like crap too lol







but any help would be good i wanna get the most out of this motor i can 8v POWER! http://****************.com/smile/emthup.gif


----------



## salz2135 (Sep 18, 2006)

I would like confirmation as well, but I believe the rev limiter is incorporated into the fuel pump relay on vehicles equipped with CIS.


----------



## WaterWheels (Aug 14, 2005)

Pump relay no, but if I recall correctly it is located in one of the ECUs the knock sensor ignition control box or the fuel control box. Years ago it was suggested on 8v cars to use a 16v knock box to alter the limiter, can't say if that worked as I never tried. The limit is accomplished via altering the fuel delivery so I would think it is really located in the fuel control box. Try this, don't say I told you to do it though. There is a single wire which connects the ignition box to the fuel box. It is I believe blue in color and connects to the fuel box at pin 25 if I recall. Cut it.


----------



## ziddey (Apr 16, 2006)

*Re: (WaterWheels)*

I've got an 85 gli that seemingly has no rev limiter. When I got it, the middle wire to the hall sender was connected to ground. The fuel pumps ran full time. I imagine this is similar to using a horn relay in place of the fuel pump relay. I know the relay on cis-e+knockbox doesn't have a built in rev limiter like cis-e cars (and I'm guessing any non-knockbox cis car). Before I corrected the middle hall sender wire, I was seeing hit 7k on bad shifts when I had horrible shift linkage bushings. When I refreshed the wiring, I also switched to a 16v knockbox and haven't revved it to 7k again, but there's still no rev limit before then.


----------



## 4ePikanini (Aug 29, 2007)

my 95 carb has a rev limiter so it might have something to do with the rpm signal from the gearbox or the hall sender on the dizzy.


----------



## TheMajic86GTI (Aug 9, 2009)

*Re: (fourie_marius)*

On the 8v cis-e cars they hav a rev limiter on the ECU and knockbox. So the safe way i was told so if u ever happen to crash(fuel pumps will turn off and u dont cause a fire) was to change ur fuel pump relay out to a fox one or use the horn relay like mentioned above that doesnt have the 4th pin and switch ur 8v ECU to a 16v ECU and ur rev limiter now will be like 7300 instead of like 6200rpm...I will be trying out this setup once my motor is done to see if it works...


----------



## WaterWheels (Aug 14, 2005)

With CIS-e it seems that the limiter is in the knock box and that wire I talked about is the link to the fuel box, i.e. telling it to cut fuel until the RPMs drop again. That is the reason cutting this wire seems to work, at least many people say so or swear by it. So, 8v knock box box 0 = lower setting for that signal while 16v knock box has a higher setting.
An 85' would not have this function and the limiter is either in the pump relay or the ignition distributor rotor (those wide ones with a spring in the middle) I would think. Carburetor cars would have to have it in the ignition or use a control box and electrical connection on the carb. The transmission would not work as it would have to be set different for each gear, that would be a nightmare I think.
I doubt the wire to the knocksensor would have anything to do in any way with the engine limiter, can't see how?


----------



## ziddey (Apr 16, 2006)

*Re: (WaterWheels)*

The 85 and 86 gli's should be the same, except ht vs rd engine.
I don't think a fox relay would work in a cis-e+knock application. The rev limiter is built into the fox relay. That's why I switched to an audi 5cyl fuel pump relay. Not sure where the rev limiter is now, but I haven't hit it.
Rev limiter should be handled by the knock box, as people are saying. It's a common swap to upgrade the fox cis-e ecu with one from an mk2 to gain wot enrichment capability. I haven't rigged any wires up yet, but swapped the ecu in just to see if it'd work. Everything is the same. No new rev limit.


----------



## TheMajic86GTI (Aug 9, 2009)

*Re: (ziddey)*

Are u sure its not in the ECU aswell?? Cuz i spoke to Collins from TT directly and he told me there is one in the knock box and in the ECU. I sure would like to bust this myth with the truth as im getting close to finishing the motor and would love to rev at 8000rpm







. 


_Quote, originally posted by *ziddey* »_That's why I switched to an audi 5cyl fuel pump relay.

Wut model and year Audi did u get the relay for?


----------



## ziddey (Apr 16, 2006)

*Re: (TheMajic86GTI)*

Here's the stock fox: http://www.autohausaz.com/sear...Relay
Part number 321906059H 

Here's an 85 5000s: http://www.autohausaz.com/sear...Relay
Part nunber 321906059F 
Before the rev limit was somewhere between 6000 and 6200 (not sure exactly where since my tach was off)
Now I can rev past 6500 fine (not sure where the limit is but I haven't exceeded 7000 in the fox).


----------



## ABA Scirocco (May 30, 2001)

*Re: (ziddey)*

CIS system and CIS-e systems that do NOT have a knock sensor (i.e Fox CIS-e) have their rev limiters built into the fuel pump relay, 059F relay that TheMajic86GTI referred to does not have a rev limiter. CIS-e systems that DO have a knock sensor, have their fuel pump controlled by the ground signal from the knock sensor control unit (pin 10), when you hit the rev limit, it cut the ground to the fuel pump relay. If you maintain the ground, the fuel pump stays on and the rev limiter doesn't doesn't kick in. The easiest way of safely maintaining the the ground is to connect a normally open oil pressure switch to connect the wire running from pin 10 of the KSCU, like this.








I've heard from a reliable source that some but not all KSCU's also have an ignition cut out rev limiter but in those KSCU's that have this, it's set MUCH higher than the normal fuel cut out rev limiter. On my previous Scirocco, I ran with the KS system from an 85 Jetta Carat, and I was able to rev up to 8000 rpm (perhaps beyond) without tripping a rev limiter. 
I should end this by saying that all of my experience with KSCU's was derived from installing one in a Scirocco with CIS-lamdba, I've never actually done what I suggest here, so take this for what it's worth and if you wish to attempt it, I can't be of any additional assistance.
And for reference, here's the wiring diagram for the fuel and ignitions systems of an 86 with CIS-e and a knock sensor












_Modified by ABA Scirocco at 9:30 PM 3-11-2010_


----------



## nwvwgli (Aug 18, 2007)

*Re: (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_CIS system and CIS-e systems that do NOT have a knock sensor (i.e Fox CIS-e) have their rev limiters built into the fuel pump relay, 059F relay that TheMajic86GTI referred to does not have a rev limiter. CIS-e systems that DO have a knock sensor, have their fuel pump controlled by the ground signal from the knock sensor control unit (pin 10), when you hit the rev limit, it cut the ground to the fuel pump relay. If you maintain the ground, the fuel pump stays on and the rev limiter doesn't doesn't kick in. The easiest way of safely maintaining the the ground is to connect a normally open oil pressure switch to connect the wire running from pin 10 of the KSCU, like this.








I've heard from a reliable source that some but not all KSCU's also have an ignition cut out rev limiter but in those KSCU's that have this, it's set MUCH higher than the normal fuel cut out rev limiter. On my previous Scirocco, I ran with the KS system from an 85 Jetta Carat, and I was able to rev up to 8000 rpm (perhaps beyond) without tripping a rev limiter. 
I should end this by saying that all of my experience with KSCU's was derived from installing one in a Scirocco with CIS-lamdba, I've never actually done what I suggest here, so take this for what it's worth and if you wish to attempt it, I can't be of any additional assistance.
And for reference, here's the wiring diagram for the fuel and ignitions systems of an 86 with CIS-e and a knock sensor








_Modified by ABA Scirocco at 9:30 PM 3-11-2010_

this seems to be the best way im gonna atempt this tommorow and will update what i find cant believe this kind of stuff isnt in a faq or anything i guess nobody builds 8v's on cis anymore lol 
any imput on the knock sensor bushing that come with the tt digi 2 chips
this is good keep the sugestions comming http://****************.com/smile/emthup.gif


----------



## kpn3nc (Jul 5, 2008)

what about digi2 rev limiter?


----------



## ziddey (Apr 16, 2006)

*Re: (kpn3nc)*


_Quote, originally posted by *kpn3nc* »_what about digi2 rev limiter?
ecu controlled. chip it


----------



## ABA Scirocco (May 30, 2001)

*Re: (ziddey)*


_Quote, originally posted by *kpn3nc* »_what about digi2 rev limiter?


_Quote, originally posted by *ziddey* »_ecu controlled. chip it

That's kind of obvious but there are a lot of ways to implement a rev limiter. For example, does it pull out timing as it approaches the rev limit as sort of a "soft" rev limiter? Does it cut the ignition, cut the fuel? So, perhaps a better or more precise question would have been, how does digifant implement it's rev limiter?


----------



## kpn3nc (Jul 5, 2008)

*Re: (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_
That's kind of obvious but there are a lot of ways to implement a rev limiter. For example, does it pull out timing as it approaches the rev limit as sort of a "soft" rev limiter? Does it cut the ignition, cut the fuel? So, perhaps a better or more precise question would have been, how does digifant implement it's rev limiter? 

thanks for clearing that up.


----------



## kpn3nc (Jul 5, 2008)

I had a question pertaining to your website, ABA rocco. that was about 3mm you took off of the 1.8(?) intermediate shaft to put in the aba block? i'm pretty sure that's what I have...as I didn't build the motor. I went to a j/y to pull an aba distributor, and it wasn't until I returned to my house to pull my distributor only to find it had a mk2 gear, 'cause it was a digi distributor, and a TT adapter ring. I guess I didn't really state that question clearly. do you have to modify digi2 intermediate shafts when you put them into aba blocks? thanks for being resourceful.


_Modified by kpn3nc at 9:16 PM 3-16-2010_


----------



## ABA Scirocco (May 30, 2001)

*Re: (kpn3nc)*

Yes, unmodified the gear is DANGEROUSLY close to the #4 connecting rod, modifying the gear provides the clearance necessary to insure there no unfortunate collision at speed. 
Personally, what I'd do is keep it simple and safe; use an ABA intermediate shaft and an ABA distributor and modify the ABA distributor to work with the digifant electronics. It's really easy to do, Click Here.


----------



## chois (May 12, 2000)

Quick note to others that may dig this thread up. Yes the 16v knock boxes have a higher rev limit. They also have a less aggressive timing curve than the 8v boxes. I would look at the other solutions in this thread for rev limiter removal/raising.


----------



## ziddey (Apr 16, 2006)

*Re: (chois)*


_Quote, originally posted by *chois* »_Quick note to others that may dig this thread up. Yes the 16v knock boxes have a higher rev limit. They also have a less aggressive timing curve than the 8v boxes. I would look at the other solutions in this thread for rev limiter removal/raising.
I don't have the actual numbers handy at the moment, but the difference isn't too severe. I've been running a 16v knock box in my 8v with the base ignition timing set to 10*BTDC. makes up for any lost timing. not sure if it's pulling timing ever though, but doesn't seem like it.


----------



## chois (May 12, 2000)

Yeah that will work fine, people just need to know to bump the base.
I just run fixed timing. 31 at idle and at 6k. It works fine, but not something I would do on a street car.


----------



## ziddey (Apr 16, 2006)

*Re: (chois)*


_Quote, originally posted by *chois* »_Yeah that will work fine, people just need to know to bump the base.
I just run fixed timing. 31 at idle and at 6k. It works fine, but not something I would do on a street car.
wtf?? you have a build thread? i'm intrigued


----------



## chois (May 12, 2000)

Nah. No time to make one. It's just an SCCA IT car. .040 over, balanced, stock cam/head/intake, TT header and a bunch of time on the dyno getting it right. Running CIS-E with adjustable fuel enrichment and fixed timing. Nice torque curve and a solid 115whp on 100 unleaded


----------



## kpn3nc (Jul 5, 2008)

*Re: (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_Yes, unmodified the gear is DANGEROUSLY close to the #4 connecting rod, modifying the gear provides the clearance necessary to insure there no unfortunate collision at speed. 
Personally, what I'd do is keep it simple and safe; use an ABA intermediate shaft and an ABA distributor and modify the ABA distributor to work with the digifant electronics. It's really easy to do, Click Here. 

thanks for that. I'll keep it in mind, but I didn't build my motor, the PO did. I bought it with a bad ECU (owner didn't know the problem and wanted out of mk2s) for $850. it's an aba bottom (bout 70k on it now) blueprinted and balanced, digi2 p&p, 268 cam, header, and that damn digi2 intermediate shaft, haha. I'm curious to know if he had that shaft shaved..I want to say probably because it was professionally built. I saw the receipt, $1602 for the bottom end alone.







but who knows? at least I don't really have to take anything apart though, they made it simple there, just use the TT adapter ring. slips right on. Wish I didn't go through all that mess.







oh well, it was a fairly cheap learning experience. $15 bucks at the junkyard.
on another note, sorry to the PO for mini-micro thread jacking. http://****************.com/smile/emthup.gif 


_Modified by kpn3nc at 1:33 PM 3-17-2010_


----------



## ABA Scirocco (May 30, 2001)

*Re: (kpn3nc)*

Pull the distributor and turn the engine over by hand as you look through the distributor hole, I'm not sure how much you'll be able to see but maybe it'll be enough.


----------



## kpn3nc (Jul 5, 2008)

not too worried about damaging anything. besides, it'd give me an excuse to go vr quicker.


----------



## ABA Scirocco (May 30, 2001)

*Re: (kpn3nc)*

Always good to have a backup plan http://****************.com/smile/emthup.gif


----------



## deer_eggs (Oct 4, 2006)

*Re: (ABA Scirocco)*

Lots of good information here, would any of it apply to removing the rev-limiter on a car with CIS-Lambda?


----------



## ABA Scirocco (May 30, 2001)

*Re: (deer_eggs)*

Removing the rev limiter from CIS-Lambda systems is VERY easy, just replace your current fuel pump relay with relay part number 321 906 059*F*


----------

