tkerrmd

Hi all.

Well at the Sebring Club race, I had a great time and did great in the sprint race. My wingman's car threw a rod however.
Next day in the enduro made it close to the end and lost a head gasket in my 944S race car.

Looked at and bought a nice 944 turbo race prepared.

It has a boost controller which I dont want to touch. And for class racing I think I need to run stock boost and dont want to blow a head gasket.

any 944 turbo racers able to give me advice on boost or on anything that has to do with keeping these cars going for racing??

Thanks in advance!

tom

Larry Herman

From what I have seen, on most 944 turbos with adjustable boost, you just turn it up till the motor blows and then back off a little.

Actually, if the PO has changed the way the car controls the boost (i.e. a boost controller) then your car is not legal for PCA stock or prepared, and you will have to re-install the stock componants; waste gate, cycling valve, chips etc.

Techno Duck

It depends what chips the car is running, Weltmeister, Vitesse, Autothority..etc. For Autothority and Weltmeister, you should not exceed 15psi as you will max out the injector duty cycle (And blow a head gasket eventually). Best thing to do is ensure the car is in a good state of tune and running proper AFR's.

tkerrmd

Larry thanks for the answer even if you would rather see another 944 blow up I appreciate the input. I will put it back to stock. This is another stepping stone to trying to race in a Cup car, one step at a time.
My plan is 944 to the 944 turbo to a Koni Challenge type car then hopefully a late model Cup car?

Jon, the car has an AFR meter in it as well as an additional boost gauge. So the car can safely run one bar boost in enduro race condtions??

also does that mean it would be 2 bar on the factory gauge as I assume the 1 bar is atmospheric pressure?

I appreciate your help, thank you.

tom

Larry Herman

One other thing you may want to consider and that is the rod bearings. I would probably suggest getting them replaced as you do not know the history of your car, and the #2 bearing has a nasty habit of failing when subjected to high boost. If not, at least get an in-depth oil analysis to see if there is any bearing material in it. BTW my son has a 951 that is heavily tracked so we worry about the same things.

Techno Duck

High boost is not the issue for the #2 bearing, its oil starvation during high G cornering. Like any car, keep a good eye on the oil level. If you want to lessen the probability of a rod bearing failure, as mentioned consider replacing them and adding a oil pan baffle into the pan (a better one than factory). If you really want to bullet proof the bottom end, cross drilling the crank @ #2 and #3 i believe evens the flow the best. May want to read up on that from more experienced people. High boost will blow head gaskets if you cant support it with enough fuel and dont have it tuned right. Because your car is still using the AFM, im pretty sure you wont be able to lower boost by much without a fuel controller. Unless of course you go back to stock chips.

You are correct, 2 bar on the factory gauge is about 14.7psi or 1 bar actual manifold pressure. As long as the car is in a good state of tune, i wouldnt expect to have any failure during an enduro. But of course, it is a 20 year old car. So it might be mindful to remember anything is possible!

BTW, stock boost for a regular 951 (K26/6 turbo) is around 11-12psi @ 3k rpm. By redline it will have bled off to around 9psi. The 951S (K26/8) should be able to hold 11-12psi all the way to redline. Based on the pictures it looks like its an '87 or early 88 non S. So if it hasent been swapped yet, you have a K26/6. Unless of course you are running spacers..which means its a '86, but still equipped with the 26/6 .

FlyingDog

You could run NASA GTS Challenge with the modified boost components.

SeaCay

Doc:

We need to talk about the way a lot of that car is set up. Seriously, spend some time reading the good technical stuff on the 944 turbo board to see some of the things that just are not right with your current setup (PO induced error). Right off the bat, you don't want the intake cone filter right behind the intercooler, hot air at intake = bad.

To answer your original question, the only right way I know to determine safe boost is on a dyno. I didn't see what class you're planning for this, so I'm guessing it's not a stock class (is adjustable boost legal in stock?). What chips are in the car, wastegate, and wastgeate controller? Lot's of variables here, each of them will determine boost settings, but the most important is rule book first.

I may have some bits off your previous 944 turbo that you might want to use...

Gator_86_951

My 944s blew up so I bought a turbo. lulz, you have it bad sir, bad indeed.

Lots of good advice here. Who does your car preparation in tampa?

M758

How much power do you want to make?

More boost = More power but also = More money to make it last.

trackjunky

Make it hold 13 psi to redline, throw an S2 ring and pinion in it, change out the stock waste gate to a Lindsey Club Gate, then dial in the suspension.

Don't waste your time with the other bells and whistles. Learn to drive that car fast through the turns and you'll eat up a lot of more powerful, more expensive cars.

fast951

I know the car in the pictures, it belonged to a good friend of mine. At the time it sold to a guy in FL it has some nice pieces.

Feel free to email me directly!

tkerrmd

thanks again Larry you are always helpful
we threw a rod in our 944S at the Sebring Club race this past weekend.

tkerrmd

Jon
Thanks sooo much very helpful advise!

OT...........

I posted this same question as a newbie on the 951 forum with the pics and got exactly not a one!!! response!
As I have said many times, this forum certainly contains the most knowledgeable and helpful porsches guys around!! Kudo's to all again on this forum, it is a great place to turn to for good advise!!

tom

tkerrmd

thanks, was trying to run in the super cup, what would be better for this car.

by better, just want to be able to run with the group