924Board.org

morghen · Joined: 21 Jan 2005 Posts: 8886 Location: Romania

wait wait...the TB micro switches are only present and used on the cars with the lambda system? i tought that the DITC reads from them too......?
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Smoothie · Posted: Wed Mar 26, 2008 1:23 am Post subject:

Yeah, you made me look.. US cars with the o2 sensor system do use just the idle portion of the TPS for ignition (it's split off and goes to either DITC ('81-up 931) or to the idle stabilizer ('81-up 924NA) - for either one, need to know when the engine's idling, to go into idle stabilization mode). You'll have to look at your own markets' wiring diagram to see if the switch/es are present and if so, which components are affected.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

Great work Rasta!

I'll second (third) the clean install comment. It's always a goal.

Now add a wideband o2 and start slowly cranking up the pressure.

Enjoy!
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1980 931S
15psi boost, MS-II, EDIS, 951 IC, custom intake, Ford 5.0L throttle body, Forge BOV, WB o2, G31 w/LSD, 964 wheels, 968 rear sway, Bilsteins, 200# Welt. springs. A laptop, and a partridge in a pear tree.
1991 964 C4 Cabriolet

mr. dude · Joined: 14 Feb 2008 Posts: 111 Location: Michigan

This is a great write up Rasta! Great job. I've been toying around with the idea of intercooling my car in the future (probably distant future) but it's good to see other people's setups as an example.
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1986 Porsche 944

tuurbo · Posted: Fri Apr 11, 2008 9:51 pm Post subject:

Hey Rasta - You made your intercooler right? Did you use an Air to Air core and then build a box around it for liquid, or where'd you get the core?

thanks!

flosho · Posted: Sat Apr 12, 2008 1:21 am Post subject:

Tuurbo, I believe he bought most of the set up from Kenodog, who bought it from some place. Its a Spearco core, like a 252b or something.
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Rasta Monsta · Joined: 12 Jul 2006 Posts: 11724 Location: PacNW

Yes, Keno had it fabbed. I understand the core is designed as an A/W unit, and the end tanks, etc, were added.

In other words, it's not a air/air unit with a water jacket welded around it.

You considering this?
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

tuurbo · Posted: Sat Apr 12, 2008 2:00 am Post subject:

I have two air to air cores here.

No I'm not considering using an air to air core for an air to water cooler unless I hear that the cooling is excellent with that sort of configuration - possible big waste of time there.

tuurbo · Posted: Tue Sep 30, 2008 1:26 am Post subject:

You know, I clicked on some link Rasta gave me and left this web page open for a couple of days, looking back on the installation maybe half a dozen times.

What I really like about this is:

- No holes in the hood - the hood is distinctive and too many scoops looks too much like afterthought
- the amount of piping is minimal so lag is reduced
- the liquid intercooler is plumbed in a sensible way, it's put in at such an angle that it kinda looks factory conceived

Since it's been a while now that you've had time to run it, Rasta, how does it work? Is the pipe above the exhaust heat plume getting too hot? How do you know it's working?
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11724 Location: PacNW

I think its working great. I don't really have any objective evidence of this, other than the fact that the cooling medium heats up during a 25 minute track session. From a subjective standpoint, I am running 12-13 PSI with no det problems, and have mean acceleration. Shaggy used to be a bit wheezy after track sessions (slightly rough running, not that eager to scoot) but now on the way home he feels fresh and happy. I am sure that cooler intake charge has contributed to this.

The pipe entering the unit does get hot, partially from the compressed charge, and partly from exhaust heat. I think this can be reduced by insulating the piping with either wrap or a ceramic coating. My next mod to the system will be having the pipe between the turbo and IC remade out of bent tubing with fewer sections, and then having it coated.

Overall, I am very pleased with how it turned out.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

tuurbo · Posted: Tue Sep 30, 2008 3:07 am Post subject:

Hmmm. Yeah that's how my car behaves when it's doing methanol. That's what you want. It's working.

The NACA duct is tossing cold air into the same area as the hot intake charge pipe which might be cooling it down a tad, for probably a foot before it enters the intercooler. I think there must be a really turbulent area of cold and warm air mixing things up nicely, right in front of the battery box area.

The ceramic coating and/or wrap - probably worth the money to do both! What the heck - every degree counts. Ours are the hottest running cars I've ever encountered.

I'm probably naive about how this all works - but I have this simple notion that cooler is just always better when it comes to air charge. So I'm thinking I can do both methanol and an intercooler, if I want, and it'll be real cool, with a touch of fuel enrichment from the methanol.

I'm just shopping around the various installations. Fussy about what I want in an intercooler setup.

So lag isn't an issue. Hmmm wheels are churning.

There may be a few places a nozzle could be mounted just before the throttle...
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

ideola · Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI

Coating will help contain temp within the tube...not sure it will help that much with inductive heat transfer...an insulating heat shield in addition to the coating might be best...
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erstwhile owner of just about every 924 variant ever made

Kenodog · Joined: 25 Jun 2003 Posts: 2651 Location: Vancouver,B.C.

I tried to tell you to use a bigger heat exchanger.That little guy you have in the nose doesn't even come close to the size of the unit I was using.Think of this; the only cooling air coming in to your exchanger is from those 4 little holes in the nose.On my car the exchanger was the same size as the radiator and was in front of the rad too so it got ALL of the coolest air ! On a cool day here the intake temperature after the I/C DIDN'T EVEN REGISTER ON THE GAUGE -it was that cold ! (below 50 degrees F) Dude you had a great idea for a clean install but I think if you would have gotten a rad from a mid 90's Civic or something like I suggested it would be much,much cooler,especially on a track day where you are running it hard. BTW for those of you interested in the I/C unit it's a Spearco B-252 core with end tanks welded on.Glad it works for you Rasta.
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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11724 Location: PacNW

Scorpio · Posted: Thu Oct 09, 2008 10:26 pm Post subject:

hey rasta dude...you thinking of giving shaggy a little squirt of alcohol and water for some extra cooling?

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1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
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