Nitram T

Hi Rennlisters,
First post. Recently got a 1989 944 turbo race car (Project).

During the vinter I want to get familiar with it - first turbo car I own.
What are your suggestions on building a reliable turbo race car. Dedicated track only.

Previous owner blew the head gasket 2 times I’m aftaid to blow it yet again.

I have changed the fuel lines in the engine bay. Want to fit an extra bigger oilcooler. Lindsey oil baffle door is on its way once they are back in stock. Is oil starvation an issue with the 944 turbo? What other reliability additions would you recommend i do to the engine?

Should I be heat wrapping the manifold, turbo and piping?

cold Air intake?

do I need brake ducts?

The bushings are all poly and a solid transaxle mount is also going in.

I do not want more power just reliability. The car is fairly stock I’m worried that I end up with a car that brakes down all the time though.

What good track race car mods will I not be able to live without?

thanks
/M

931guru

Do you want a car that wins, or a car that runs behind everyone else? The answer to that question determines the reliability of your turbo engine.

Oddjob

Where are you/car located? What club, tracks and under what class rules will you be running? Rule limits on upgrades to engine, trans, brakes, suspension, weight?

Mileage on the engine and trans?

GPA951s

If youre going to go through the car, pull the engine.. re-gasket everything, otherwise you will chase oil leaks all the time. Do it once and be done… Get the turbo rebuilt, the two piece crossover is a godsend when you have to get at the clutch or turbo. Do the “ urethane trick” to the tranny mount. Put a mls head gasket on with ARP studs. Leave all the mas-air chip stuff off.. keep it stock and just get it dyno-tuned at 1bar boost. Ive used this formula on many race-cars including my own. Never lost a head gasket and super reliable.. about 2500 in hard parts if you leave the head and block alone.. but as long as the heads off i would recommend a valve job
i recomend RPR tuning in MD he is a wizard with tuning a stock turbo into a reliable fun track car.

Nowanker

Everything GPA951S says.
Oil pan baffle is a must.
Might as well do rod bearings while you're there, and check the oil pickup for cracks.
My personal experience was that an 'Accusump' was worthless as an oil pressure bandaid.
The factory oil pump moves oily air well enough to maintain pressure that the A-sump never discharged...

Factory brakes are pretty good. Add some cooling! Big brake kits are available too. Just the F, don't need to mess with the rear.
Check the F control arms, ball joints occasionally fail.
Enjoy!

Nitram T

Thanks guys much appreciated.

I’m in Denmark but Thanks for the garage recommedation anyway.

Engine been rebuilt not too many Miles ago. ARP studs already in.
when I do the baffle door in the pan the rod bearings will also be changed. Turbo runs 1.05 bar is that too much?

I’m after fast and reliable as super fast but blown race cars don’t win many races :-)

regulations are pretty open however I want to keep it as period and standard as possible.

no leaks whatsoever. it has coil overs all round and a Big brake kit in the front. What spring rates would be suitable with 18” full race slicks?

what kind of Oil shoul I run? 10w60 or 20w50

thanks again for sharing

Nowanker

"Fast, Cheap, Reliable.
Pick any two..."

Nitram T

true. 👍

slivel

"Previous owner blew the head gasket 2 times I’m afraid to blow it yet again".

This should be a warning sign. A stock engine running stock boost levels with fuel of the proper octane will be reliable and should not blow head gaskets. If you don't know what software the KLR and DME are using, I would start there and confirm what is in the car. If you want to produce more power you have to control the mixture.

Nitram T

Great input -Thanks
the car have been part of the Swedish turbo cup. They all had a new chip allowing for a little extra power. I do not exatly know what chip it is. I was thinking of a dyno session meassuring the Air/fuel ratio. Is there any way to adjust the mixture without changing the chip?

GPA951s

So what my dyno guy does is “ piggyback” the dme.. he can adjust the air/fuel.. boost .. make a bunch of runs.. when he is satisfied he burns a chip for it and done!
Are you in the US? Your profile doesnt show.. i run my car as a “ turbo cup” car here.. and i have won races with it, most notably against a cayman pdk car.. what a fun race that was! Our weight is limited to 2820 with driver.. 1.05 bar is fine as long as its tuned right .. if you dont all ready, get a Wideband .02 sensor… you can keep an eye on your a/f in the long straights..
i run 900lb springs in the front and 1100 in the rear

slivel

This:
VRT8x (vitesseracing.com)

Vitesse still lists a piggyback for 951's. I used the earlier version which is now about 30 years old. It still works fine and is in my son-in-laws' 951 (which used to be my car).

333pg333

It's one of those questions that really opens up a can of worms. The major part of the question is budget. Always allow for considerably more than you anticipate.

Yes, cooling is paramount. So is quality oil with decent levels of ZDDP. 20w/50 minimum. 25w/60 probably better. With 18" slicks all round oil starvation is definitely an issue. The LR baffle is virtually just a door hinge but it's probably better than nothing. Years ago I had a custom made wet sump (using stock sump) with 4 hinges, a modified pickup tube and other improvements. It cost quite a lot to have made but then that shop was expensive anyway. You could get someone locally to figure out how to make something similar. But even better would be to just get it done correctly the first time and dry sump it. With a dedicated race car it's not an issue to situate the oil tank. It is an expensive investment initially but worth it in the long run.

If you're going to open up the engine you should look to switching to these rod bearings. Much better than stock. Check out this thread but answer is in the last post. https://rennlist.com/forums/944-turb...ng-fix-10.html
https://www.summitracing.com/parts/peb-4b2475h-std

Depending on power to weight (and duration of races) you could use larger rotors and Porsche Big Reds as your brake hardware. Not too expensive and a pretty good setup until you increase power by a lot.

As your car is already a racer it's probably fairly stripped out of unecessary weight. If not, that is another place to look. By running the lightest car as possible you put less strain on other components. You could conceivably run lower boost for the same lap times which is another tick to reliability.

Lastly, I'd ask what aero mods are you allowed to make? If you have a little bit of room to modify the body, then aero is another relatively cheap modification to improve lap times. If you have to keep the car standard then make sure you use the batwing pan under the motor and also the stock diffuser. If you have to keep the car mostly stock but are allowed to put vents in the fenders and hood, then definitaly look into that. Vents can really help with heat and pressure dissipation.

Post up some pics of the car and the rules that you will have to observe. There will be some good advice in here. Also I'd suggest speaking with other guys / shops that race these cars in your area if you haven't already. Good luck!

Nitram T

thank you very much 👍
What kind of tyres do you run with those springs?

Dyno session will be interesting. The guy is really busy as He is part of a Le Mans team - travles the world during the race season. An open slot will come during the vinter.

what kind of power should it make (Ball park) std with 1.05 bar?

Nitram T

great input - Thanks.
I’ll have to find out Where the management is at first and then go down the piggy back Road if that is needed.