924Board.org

924inMN · Joined: 25 Mar 2008 Posts: 10 Location: Minnesota

First off I would like to say that this thread has been interesting and very helpful. I've been milling around on 924board for a while and decided to finally post. I've got a '79 Stock 924, with 55,000 miles. My plan is to try to throw a turbo in it, and I'm going to try to copy as best I can the work of Raceboy and 71vdubturbo. Awesome posts by the way. I'd like to try a used Garrett t2/25 at 7psi(ebay about 200$), with the stock CIS if possible, and pretty much the same set up as raceboy or vdub as fars as tubing and routing. I have access to a cnc plasma, tig, mandrel and all that good stuff so I'm not really worried about the actual fabrication part. I'm not sure if I should water cool the Garrett or if thats even a good turbo choice for a 924 N/A? Also, I'm sure this a rookie question but where does the oil feed to the turbo from? Is an intercooler necessary for a mild upgrade? If I could get to 150rwhp I would be thrilled. Is there any science to richening the fuel mixture in the stock cis? How do I know how much to advance/retard the timing without a dyno? One final one, do I need to replace any vacuum lines with an electrical pump or other source? I haven't really started yet but spring is about here and I'm trying to from a loose plan and learn as much as I can before I start. I'll definitely check through all the other posts here but this one really rocks and it would be cool if everybody kept updating. Appreciate any answers, concerns,wisdom that you guys can give me. Thanks, I'll take some pictures once it gets a little warmer up here in MN.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Min · Posted: Tue Mar 25, 2008 11:22 pm Post subject:

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Min · Posted: Wed Mar 26, 2008 12:28 am Post subject:

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Min · Posted: Wed Mar 26, 2008 12:43 am Post subject:

Min · Posted: Wed Mar 26, 2008 12:47 am Post subject:

I won't be responding in this thread anymore, rather not take it anymore off-topic than we already have.

Min
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Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Once again, a big "WHATEVER" to everything you just said. For crying out loud, I HAVE NOTHING AGAINST YOU other than your ego-maniacal insistence that any post I make about fuel delivery is a targeted attack against you.

And for the record, I DIDN'T GIVE OUT ANY ADVICE. I suggested that there are a variety of proven alternatives for modifying stock CIS. ANYONE who doubts this should go cruise around the 928 circles for a while. There are PLENTY of guys there who have modified the stock CIS using exactly the techniques I've described. In fact, a good place to start is with David Lloyd, president of the 928 Owner's Club, and part-owner of Musante Motorsports. Also, a little bit more research into the 924 GTR that surfaced on Rennlist about a year ago reveals yet another example of successful modification to stock 924 CIS without requiring a secondary fuel dizzy or a 928 fuel dizzy.

Bottom line: there are ways CIS can be modified without endangering your motor. EFI is probably the best way, but not the only way. And furthermore, even on modern EFI systems, where it is undesirable (for whatever reason) to replace the injectors and where injector flow is a limitation, rising rate FPRs are an accepted method of supplementing fuel flow.

How any of that can be construed as "bad advice" is beyond me. I'm simply pointing out alternatives.
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erstwhile owner of just about every 924 variant ever made

Min · Posted: Wed Mar 26, 2008 1:27 am Post subject:

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

I'll work on digging up some references. I have a bookmark file that is pages and pages and pages. Give me a few hours and I will post back.
_________________
erstwhile owner of just about every 924 variant ever made

924inMN · Joined: 25 Mar 2008 Posts: 10 Location: Minnesota

Thanks. I need to read up more on this whole thing, I'll check out a few books. I am also going to look into megasquirt. Vdubturbo wrote that he just richened the fuel mixture on the stock cis by adjusting an allen screw. Looking at his photo album, everything appeared to be stock. So can the stock cis and injectors deliver enough fuel for mild forced air? Is the stock ignition workable? And finally, do I have to estimate timing settings before I get to a dyno so it will run w/o damaging the engine? If dyno's the way I'll spring for some dyno time I'm not looking to get as much horsepower as raceboy did, just enough to beet those pesky Acura Integras down the road a bit. Any stock parts on the porsche which will work for turbo I would like to use/modify. Thanks for all the ideas so far. Oh yeah, I live near Minneapolis/St. Paul.

924inMN · Joined: 25 Mar 2008 Posts: 10 Location: Minnesota

Also, its nice to see people who try to help with N/A to turbo on 924's instead of just telling me to get a 931 or 944. Granted I would love to have either of those cars but I already have a pretty cherry 924 so why not squeeze a little horsepower out of it. Plus the challenge of the project will keep me sane/entertained, like vdubturbo I too get quite bored without a project.

Min · Posted: Wed Mar 26, 2008 3:15 am Post subject: