# CIS airbox mods?



## johnnyGO (Feb 23, 2009)

Ive got a 89' Audi 90 and Ive been looking all over to find a how-to or even a what-to-do for modding a CIS airbox. Any help, pointers or pics would be a godsent.


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## salz2135 (Sep 18, 2006)

What kind of modification are you looking to do? What is your goal?


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## motorbreath1800 (Jan 11, 2008)

I've been contemplating making a new airbox out of fiberglass into a 3" ducting.


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## WackyWabbitRacer (Apr 24, 2001)

*Re: CIS airbox mods? (johnnyGO)*


_Quote, originally posted by *johnnyGO* »_what-to-do for modding a CIS airbox. Any help, pointers or pics would be a godsent.

Whatever you do, don't drill large holes in the airbox as this only allows hot air from the engine compartment to enter the induction system.
A cold air duct hose from the airbox to the front of the car is the better solution.
Cheers, WWR.


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## johnnyGO (Feb 23, 2009)

*Re: (salz2135)*

Basicly Im tring to get a more direct flow of air, drop all the BS if you will. The issue Im running into is the fuel distributor, on mine the intake is the lower airbox unlike the volvo ones like this :








If I had a system like the volvo one then it would be easy, all I would have to do is run a cold air intake system.


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## jackfrost1031 (Oct 19, 2004)

*Re: (johnnyGO)*

I highly doubt the stock air box is a big restriction. Is this for packaging or performance? I would suggest porting your intake manifold or head if you want to see any gains worth having.


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## johnnyGO (Feb 23, 2009)

*Re: (jackfrost1031)*

A little bit of both, I wouldint mind not having to take a weekend just to change the air filter, lol








As for perfomance, Im not expecting a huge gain from this but as they say " something is better then nothing ". I agree with you that the box isint restricting but I would think the air flow is much more turbulent in a box vs tubing like a cold air. I would THINK a direct flow type intake vs a airbox would be like velocity stacks vs no stacks on a carburetor. 
I know the bottom half of the volvo fuel distributor bolts up to a VW 1.8's distributor so now Im wondering if it will work with my Audi's.


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## johnnyGO (Feb 23, 2009)

Im sorry guys I keep saying the fuel distributor... I mean to say the Air Flow Meter


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## jackfrost1031 (Oct 19, 2004)

*Re: (johnnyGO)*

i agree with the air filter headache! My 10v Audi takes entirely too long to get to the air filter. See Here


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## wclark (Mar 28, 2001)

*Re: CIS airbox mods? (johnnyGO)*

With my GTI hilllcimber, I cut much of the front of the air box away and made up sheet aluminum ducting to pull cold air from behind the headlight into the new opening as well as blocking off the gap between the air box and the radiator to prevent engine compartment air from heating the inlet air. Then I closed the air box side opening from the fender well labyrinth and the warm air feed from the exhaust manifold. Not sure how well this would work on a daily driver or CIS-Basic given the possibility that fuel metering could be screwed up by the "forced" air, not to mention the dirt and trash that might get sucked up, but it seemed to help get more air to my CIS-E engine, especially at high altitudes where it tended to get too rich with the old "dumb" fuel enrichment module.


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## johnnyGO (Feb 23, 2009)

*Re: CIS airbox mods? (wclark)*

My Audi is CIS-E III, so then what are you using as a filter?


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## wclark (Mar 28, 2001)

*Re: CIS airbox mods? (johnnyGO)*

I use a low restriction Amsoil foam filter which fits the stock air box.


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## MFZERO (Mar 13, 2002)

*FV-QR*

I've been toying with fitting one of these with a reducer to my 4k's air box and have it pointed towards the grill. 








I also have a spare intake manifold which may find it's self being ported and put on the car as well


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## WackyWabbitRacer (Apr 24, 2001)

*Re: (johnnyGO)*


_Quote, originally posted by *johnnyGO* »_Basically Im trying to get a more direct flow of air 

As you know, an automotive engine is primarily an air pump. Given the engine displacement, minus minor restrictions such as intake manifold and size of the intake valves, an engine will only draw only so much volume of air. 
Unless your engine is highly modified, the lower factory air box is more than adequate for the volume of air being drawn by the engine. 
Even on a dyno, the K&N air filter showed no horsepower improvement over a factory air filter, again due to the volume of air used by the engine.
Given all of that, here is a picture of my cold air induction system on my old SCCA H-Production racer with a Volvo lower aluminum air tray, VWMS fuel distributor, and full race 1.6L engine.
















Cheers, WWR.


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## BSD (Jul 8, 2008)

Nice setup wwr.


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## BobinNM (Feb 3, 2007)

*Re: (johnnyGO)*

What year and model volvo is the pic of the air/CIS unit from?


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## WackyWabbitRacer (Apr 24, 2001)

*Re: (BobinNM)*


_Quote, originally posted by *BobinNM* »_What year and model volvo is the pic of the air/CIS unit from?

Don't know Volvos...but believe I pulled the lower aluminum air tray form a 240 model. The air tray is buried deep in the engine compartment, and it is hard to see.
The fuel distributor is a VWMS unit.
Cheers, WWR.


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## johnnyGO (Feb 23, 2009)

Here is something that may help the Audi CIS guys. I went down to the local motorcycle shop and found this little gem, so no more BS just to change the stock filter


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## redGTInj (Jul 6, 2003)

*Re: (johnnyGO)*

still working on my "contraption" for N/A mk2 GTi 16v, with passenger side headlight removed..


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## johnnyGO (Feb 23, 2009)

*Re: (redGTInj)*

Ya thats the issue I have at the moment (IE: headlight), so thats why I had to go with a much smaller dirtbike filter...
I know this is off topic but what cars are you guys getting the 50mm throttle bodys from?


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## turbinepowered (Mar 19, 2007)

*Re: (johnnyGO)*


_Quote, originally posted by *johnnyGO* »_









I dunno, this just seems like it'd draw nothing but hot engine compartment air.


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## johnnyGO (Feb 23, 2009)

Ya its prob going to pull "luke warm" air, I did remove the rear headlight cover so pleanty of outside air is getting through. I have to cut a lip down on the airbox then Ill be able to turn the filter torwards the fender vs the motor side.


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## BSD (Jul 8, 2008)

I'll post a picture of my setup tonight and see what you guys think of it.. 
Steve-


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## BSD (Jul 8, 2008)

*Re: (BSD)*









That is a view from inside the engine bay, where my 3" intake tube goes through the charcoal canister hole.








There is my air filter, is it behind the splash gaurd, avoiding water and snow.. I drove with it there All winter and had No issues at all.








Steve-


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## redGTInj (Jul 6, 2003)

*Re: (BSD)*

what car is this in??
and no flat filter in the airbox, just the cone style?


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## BSD (Jul 8, 2008)

Yep, just the cone style. Its in an 87 Jetta coupe.








Excuse the filthy engine bay btw, lol.
Steve-


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## mrbatavus (Nov 29, 2008)

*Re: (BSD)*

sick dude, do you think you could get more pictures of this setup, i may run something like this, hows it sound?


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## BSD (Jul 8, 2008)

I sure can, i'll just pull the box out when I put my volvo dizzy on it.
I really like how is sounded, kinda had a mean little gurgle to it around 3k..








I can't hear it anymore though because my exhaust. =[
Steve-


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## mrbatavus (Nov 29, 2008)

*Re: (BSD)*

cool, thanks


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