Clutch Disk: springs or no springs?
03-19-2006, 10:11 PM
#16
Rennlist Member
You have to understand that those springs make you lose some torque, however, springs absorb force. Without springs, the force gets absorbed into other drivetrain components and that's when you break ****! I would put a spring clutch in unless your car is just for the track.
03-20-2006, 03:17 AM
#17
Three Wheelin'
Greg, FWIW the combination of the KEP and either the Cup or 930 disc seems to be the most tried/tested system capable of the heavy lifting required for a modified 951.
Also FYI, I ordered my clutch system, along with all the seals/gaskets for my engine rebuild, from Engine Builders Supply. http://ebsracing.com/ Don over there was very easy to deal with on the phone and prepared a series of quotes for me from simply asking "I need all the engine seals & gaskets you replace in a rebuild". Also, the bulk order I made ($1750 total) included excellent discounts. For instance, the KEP was only $509, $90 off their list price and everywhere else. The 930 disc was $250, compared to $300+ elsewhere. There were similar discounts to these on many of the items in my order.
Also FYI, I ordered my clutch system, along with all the seals/gaskets for my engine rebuild, from Engine Builders Supply. http://ebsracing.com/ Don over there was very easy to deal with on the phone and prepared a series of quotes for me from simply asking "I need all the engine seals & gaskets you replace in a rebuild". Also, the bulk order I made ($1750 total) included excellent discounts. For instance, the KEP was only $509, $90 off their list price and everywhere else. The 930 disc was $250, compared to $300+ elsewhere. There were similar discounts to these on many of the items in my order.
03-20-2006, 11:55 PM
#18
Burning Brakes
Thread Starter
DanG,
Thanks for the heads up. I haven't done any research on the 930 clutch disk. Although I know those cars can put down some increadable power. Seems like it would be an obvious choice. I will look into it. I will also take a look at Engine Builders Supply. Good looking out. I'll keep everyone posted. Thanks.
GCB951.
Thanks for the heads up. I haven't done any research on the 930 clutch disk. Although I know those cars can put down some increadable power. Seems like it would be an obvious choice. I will look into it. I will also take a look at Engine Builders Supply. Good looking out. I'll keep everyone posted. Thanks.
GCB951.
03-21-2006, 12:17 AM
#19
Three Wheelin'
FYI, the 930 disc is very similar to the Cup disc, except with more friction material that should equal longer wear...
https://rennlist.com/forums/showthre...05#post2558705
Check out Jason Burkett's posts, #11 and 16, for the facts.
https://rennlist.com/forums/showthre...05#post2558705
Check out Jason Burkett's posts, #11 and 16, for the facts.
03-21-2006, 06:30 AM
#21
A lot of 951's have spun their clutches and do not know it. If you look through the Rennlist history, you will see MANY dynos around 370-380 RWTORQUE with larger turbos.....hmmmmmmmm, why do you suppose this is????. If you inquire about burnt brake smell, the dyno operator will tell you it is the dyno brake - for liability sake - they are not stupid.
The 2 valve turbo engine has an incredible torque-rise - the stock clutch is no match for raised power levels. Go ahead and search the entire internet for a dyno graph with the torque line which rises at an angle more steep than a modified 951 - ANY 951. Good luck. It is my opinion that Porsche and other Japanese manufacturers started using 4 valve heads to TAME the beasts - not improve their performance.
Just a word to the very wise.
The 2 valve turbo engine has an incredible torque-rise - the stock clutch is no match for raised power levels. Go ahead and search the entire internet for a dyno graph with the torque line which rises at an angle more steep than a modified 951 - ANY 951. Good luck. It is my opinion that Porsche and other Japanese manufacturers started using 4 valve heads to TAME the beasts - not improve their performance.
Just a word to the very wise.
Last edited by special tool; 03-21-2006 at 06:50 AM.
03-21-2006, 12:27 PM
#22
Burning Brakes
Thread Starter
special tool,
I am glad I got your attention with this thread. I was hoping to hear what kind of clutch you are running. I am hoping for around 350ish-whp with all the mods I have done. I will be running a similar set up as Ted Wright had on his previous 951. He took me for a ride and his clutch was slipping at only 11psi. That was after he did a few hot dyno runs. I don't want to run into that problem. And I know you probably have the best advise to prevent it. Let me know what you think. Any suggestions would be very helpful. Thanks in advance.
GCB951.
I am glad I got your attention with this thread. I was hoping to hear what kind of clutch you are running. I am hoping for around 350ish-whp with all the mods I have done. I will be running a similar set up as Ted Wright had on his previous 951. He took me for a ride and his clutch was slipping at only 11psi. That was after he did a few hot dyno runs. I don't want to run into that problem. And I know you probably have the best advise to prevent it. Let me know what you think. Any suggestions would be very helpful. Thanks in advance.
GCB951.
