924Board.org

dreamgts · Joined: 29 Dec 2009 Posts: 504 Location: malta

I intend to revive a 79 Porsche 924 and I am considering loads of engine updates to the vehicle required thru other members who have been very helpful and enlightened me on the subjects. All the info is being considered beleive me.
Now I wish to have other opinions regarding body style. Since I would like to leave the vehicle in the 70;s look i was wondering if any of the forum members have any ideas about body kits fitted to racers during the period (70;s). I have done some research and iy seems to be that the only available style look was the D production for the seventies, other kits seem to have been introduced in the 80;s. Suggestions and directing would be appreciated.

dreamgts
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2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

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

Personally, I absolutely LOVE the D Prod look. There was also a C Prod, but it is exceptionally rare, and I'm not aware that any aftermarket kits are available for it. I have BOATLOADS of photos of vintage 924 / 944 racecars here:
http://picasaweb.google.com/streetlegalporsche
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erstwhile owner of just about every 924 variant ever made

dreamgts · Joined: 29 Dec 2009 Posts: 504 Location: malta

Very interesting pics. It seems that the D Prod was kept as factory look as possible except for the front spoliers. I Like the factory look wedge shape and might conclude on this. I am also choosing 70;s sponsor colours for the car probably Gulf since Iv never seen a car in that look in Malta. Does anyone know what engne mods were used since these were 70's old school type mods and performance. Iv seen one with webers, That is really 70's but were these installed or factory fitted? would these have / produce more power output that the CIS system, obviously webers would include some cylinder head mods too. Any info on this.

Thanks
dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

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

The 924.org History & Models section has a pretty good bit of info on the D-Prod. The Parts List is tantalizing...
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erstwhile owner of just about every 924 variant ever made

dreamgts · Joined: 29 Dec 2009 Posts: 504 Location: malta

Nein37 · Joined: 29 Dec 2009 Posts: 513 Location: New London, CT

Rocco R16V · Joined: 03 May 2009 Posts: 497 Location: PNW

I may be in the minority but I think the D-prod looks great, even better than the CGT.
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"Government exists to protect us from each other. Where government has gone beyond its limits is in deciding to protect us from ourselves. "
Ronald Reagan

dreamgts · Joined: 29 Dec 2009 Posts: 504 Location: malta

Nein37 · Joined: 29 Dec 2009 Posts: 513 Location: New London, CT

Not certain what exactly you are asking but the D-Prod engine itself was tuned to output around 175hp. The lower weight of the cars further enhanced its performance. Also I have heard the same regarding weight to hp, that 100lbs less will give a performance jump analogous to a 10hp increase in engine output. So yes... 250lbs less will be equal to 25hp.
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1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.

Rich H · Posted: Tue Jan 05, 2010 4:55 am Post subject:

What he said.

Power does not equate to weight in that manner, what you on about is power to weight where you can make up for lack of power by lowering the weight.

Porsche 924, 125 hp 1.25 tons (for the sake of argument) so 100 bhp/ton
turbo 924, 175 hp 1.25 tons = 140 bhp/ton

My Elise (Before mods) 118 bhp, 0.75 tons = 157 bhp/ton

Less power but faster acceleration. In a long drag the Elsie tops out at about 120 though and I'd rather take the Porker on a long trip!!

So loosing weight can give performance gains in the same way more power can.

D Prod has a ported head, carbs and a proper exhaust (Exiting under the sill!) that makes 175 bhp then it was lightened to say a ton so you get 175 bhp/ton so it'd be properly quick

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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

Imafordguy · Joined: 06 Dec 2009 Posts: 189 Location: Eugene Or.

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

There were definitely points-based ignition on the very early production cars, but AFAIK the only factory-delivered carbureted 924s were the 14 D Production factory racers.

The significant power-adding components for the D-Prod were 11.3:1 CR pistons, 931 head, the Kugelfischer mechanical injection system (a recent relic just sold on eBay, see photo below to see how different the pump is from our electric pumps), quad throttle bodies, a tuned stainless header and exhaust, a dry sump, and a lightened flywheel. The factory parts don't indicate that the rods or pistons were any different, other than the CR.

On top of all this, the car had major enhancements to the suspension, so it not only was lighter and more powerful, but faster than a stock 924.
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erstwhile owner of just about every 924 variant ever made

dreamgts · Joined: 29 Dec 2009 Posts: 504 Location: malta

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

The most common Carb conversion was the weber setup, and you may be in luck, as a board member (StienbargerR) here recently posted a complete setup for sale:
http://www.924board.org/viewtopic.php?t=31125
I believe Ryan's setup is a new, never-installed package, so the nice thing is that you wouldn't have to worry about rebuilding the carbs, just install and go. You could mimic a pretty decent D-Prod setup by using something like these and a Stahl header (which, to answer your earlier question, are pretty decent from what I understand). Going the 931 head route will definitely make things a lot harder, so you might just want to keep things simple and stick with your NA head, but maybe go with the big valve package that I can now source for you.

Another thing to consider would be getting 11.3:1 CR pistons custom from Diamond Racing, who are local to me here in Detroit, same brand I'll be running in my UWB project, and I know 924RACR, his racing partner Chris, and Fifty50Plus all have their pistons in the ITB cars.

At one time I was considering a carb swap on my NA, and during that evaluation process, I purchased both a Weber setup and a Dellorto setup. I sold both of them, and DOCO has a pretty good thread going on his conversion using the Weber setup he bought from me.
http://www.924board.org/viewtopic.php?t=28886

The guy who bought my Dellortos hasn't been around much, so I don't know how far along he might be.

Dellortos:
http://lh6.ggpht.com/__pqkhEfdq8I/SNB8OQ4oW7I/AAAAAAAAFso/sUgX7Zwja90/s400/PICT0799.JPG

Webers:
http://lh3.ggpht.com/__pqkhEfdq8I/SNB8PHi2osI/AAAAAAAAFsw/GF4xiY6GQTU/s400/PICT0800.JPG
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erstwhile owner of just about every 924 variant ever made

dreamgts · Joined: 29 Dec 2009 Posts: 504 Location: malta