924Board.org

[Scott Sanda]

Not that I will necessarily follow them.....

I want to get my GTR back on the track, at PCA and Historic races.

I have 3 motor options:

1. Re tune/de tune the current 3L 4v so that it doesn't hand grenade. This would be the cheapest.

2. Build a modern 4V 2.5L 944 turbo, using Motec, modern turbo, intercooler, etc. Guestimate is a 550HP motor will run less than 2 bar and run all day, if done right.

3. Take my Dprod spares: Great block, turbo head, etc, and build a 924 GTR motor, again using motec, modern FI, modern turbo, etc. Guesstimate there is about 450-470 with lots of reliability.
This is going back to the cars roots, since it was Heimraths tube chassis 924 GTR running in TA in the early 80's.

Assuming the budget is available for 2 and 3 (not sure it is), which option should I go with, and why?

Scott

[morghen]

so the aluminium engine will hold 550hp all day but the iron one wont hold 450 reliably?

Build a 3L turbo and make 500 hp out of that.
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https://www.the924.com

[Cedric]

Of course the iron block, its what the car came with, at least what i would have chosen if I were in your seat. Even though its been hot rodded during the years i think its more true to the original car
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1980 924 Turbo
www.instagram.com/garagecedric/

[Fasteddie313]

[924RACR]

Sorta depends what your motivations are for bringing the car out, which I'm not certain on.

My first thought is #2, 'cause it's inexpensive, easy, and you can beat on it all day, throw away wrecked motors etc all day long - at least relative to the last option. This would also seem to make the car follow in the 944 GTP footsteps, at least a bit?

Doesn't sound like you're all that interested in #1, otherwise you wouldn't be asking for thoughts, you'd just do it, since it's easy.

#3 would of course be more correct - but it's always easy to spend someone else's money!

So I guess the question is what do you plan to do with the car? Obviously not SCCA, and I'm assuming you still have the Caddy to get your fix there (BTW did I mention I'm working with Buttermore Jr. these days? Strange how these things work out - even more when you consider that we're working on the new V's. Small world!).

So presumably this is for running Vintage, maybe also PCA?

I can sorta relate to the challenge of what to do with a car that's becoming more of a museum piece than a racecar; even my old #77 is getting beat up to a point where I'm reluctant to keep running SCCA too long. It's still competitive by far, but I hate watching it get beat on by sharing the track with idiots...

By contrast, the new car's just a tool, and as long as the guts are straight and solid, I don't care so much how I keep throwing away this or that bit and try over, build new engines and make new parts/bodywork...

Cheers...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[ideola]

I agree with #2. #3 is more period correct, but those historic parts that are starting to fetch crazy prices. If you truly intend to be competitive on the track, do you really want to risk those expensive historic bits? Might be best to hold those in reserve for when the car will be retired to less demanding duty.

Incidentally, now that I'm in the Chicago burbs (Woodstock), I really gotta take you up on the offer to come by and check out the cars in person!
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erstwhile owner of just about every 924 variant ever made

[Scott Sanda]

Hi Vaughan,

Are you working for GM now, or still with Bosch and just working on Caddy program?

Motivation is simple: Fun car, want to run it again. PCA and HSR. The 3L will never again be competitive in SCCA GT2, since they rolled the STO V8's into the class.

I'm probably going to just refresh and re tune the 3L for now, the other options are just too expensive. You should see some of the quotes I have for building the 16V turbo. North of 50K....

Ultimately, I think a 924 T would be the ticket, but I also agree that at that point, it would not be something actively raced any longer, due to very limited supplies of "stuff".

I'm still running the Caddy in AS. Actually ran it at the Classic 24 at Daytona last year as well with HSR. Had a Rapid Unintended Dis-assembly issue due to a stock rod bolt. Apparently, it did not like being feathered at 7K rpm over and over again before the Bus stop. Different R&P is going to fix that issue, by changing 5th gears top end to 165mph, up from 155.

New motor is a pro built "showroom stock" piece, using every allowable thing, including overbore and ARP rod bolts. The motor that popped was a true crate motor, right out of the box from GM. Crappy tolerances and uneven build included.

Ideola, any time you want to make the short drive, let me know. Next 2 weeks are bad, but after that.... 708 205 5852 (cell)

[924RACR]

Still Bosch, now Bosch Engineering though, and yes, working on the V's at the moment (as well as the 'Vettes)...

Funny, those stock rod bolts do love to be a problem, don't they...

Also amusing, seems that a new CTS-V racecar has surfaced here at Waterford! Not certain who's running it just yet, presumably an AS car, current paint is black and purple... looking forward to seeing it out there this summer...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Scott Sanda]

Matt Chojnacki.

I think he is a GM engineer. and I think his car is an LS2, not an LS6. He plans on running SCCA this season, he has been picking my brain extensively.

It will be fun to have another one in class.

[924RACR]

Cool! Yeah, I'd expect he's a GM engineer; most of those guys are, and I work with most of 'em.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype