Richgreenster

Took my car out to the track to run a few laps. The motor that I had rebuilt ran perfectly thanks to Lindsey Racing and John from Vitesse for all of their help.

One problem I am running into that has me stumped is that my brand new clutch (930 disc with stock 951 PP) will slipp at 6+ psi of boost. I had the fly wheel lightened and my clutch fork strenghened. but other than that everything is brand new and stock.

One thing that I think is going on is that the slave cylinder is not retracting back far enough thus keeping the clutch fork slightly pressed.

Is there an adjustment or is my clutch slave or master cylinder bad? Or maybe something else?


The track was a blast! We need more Porsches out. Only 3 showed up (968 and a caymen) out of 104 cars.

Rock

I had this happen to me when I adjusted the new master cylinder I put in improperly.

It was adjusted too far out, so it was partially open even when the pedal was not engaged.

Clarks garage has a good read up on adjusting it, should that happen to be your problem

racerxrick

I hope that adjustment works for you....I just wanted to say thanks for the pic!

Techno Duck

Adjust the free play on the clutch pedal with the master cylinder push rod. Clarks has directions on how to do it, check page 30-1 in the factory transmission manual also.

My car had this same problem prior to buying it. The master and slave were changed but the pushrod was adjusted incorrectly. When the car was up to normal operating temp the clutch would slip as soon as you got on boost. I readjusted everything after buying the car and all was fine for about 15k miles or so until the throwout bearing started making a racket.

Richgreenster

I really think that this is the problem. I can't wait to get it fixed so that I can start really playing with the car.

6psi of boost did not give me much power but I did manage to get up to 102mph on the track. Just to give a point of refference, the fastest that I heard of last night only managed 120ish which were 3 cars competeing against each other for bragging rights. A brand new Z06, Viper and a pumped up supercharged Stang. I don't think that I would have been able to hit 120 but I would have been a bit faster.

All said it was a very fun night with a lot of really friendly people.

Norm Swanberg

I got a new aluminum flywheel and it slipped at first. The instructions said it needed to be broken in for 500 miles. I put 300+ on it, shifting a fair amount and it was ok. Just a thought. Good luck, Norm

Richgreenster

UPDATE!

Had a chance to adjust the master cyl of the clutch today. Great news it was out of adjustment. Adjusted it and it will now pull strong to about 10psi (Spring pressure only) without slipping. Funny thing is that it was too loose, which for some wierd reason does not let the slave cyl release all the way back. I dont get how it works but when adjusted correctly all is well.
Yes for a brief moment, all is well with the 951. LOL

Thanks to all the help.

Richgreenster

oops! Spoke too soon. Still slipping. Now at 10psi. better but not good

gcb951

Is the clutch pedal getting stuck a little past half way from the floor sometimes? Might need to bleed the system?

Richgreenster

Nope. It is as smooth as can be.