George D

ZerMATT,

I've been a fan of these cars for about 20 years, and have modded about 23 other sports cars over the years. My 951 cars have used/tried many aftermarket clutches. Know, the factory parts are the best as long as your tq goals meet their limits. If your tq levels are about 100ft lbs above stock levels, Jason is correct. Factory parts have been put through R&D expense that NO other aftermarket company will ever consider. It would bankrupt them.

PM me if you want the list of clutch manufacturers I've used. I spent a few bucks to make a factory sport 911 PP work on my 951/968.

Darwantae951

One aspect of Southbend that appealed to me. It was all stock components, and went together as such. Good luck!

George D

ModdedEverything,

All aftermarket vendors use OE parts. Southbend may have some time, money, and effort into different materials to deal with us 951 nuts. My succienct point was to make sure that the R&D effort from the orignal scrivener gets some credit.

Kindest Regards,

George

George D

What I meant to state to all reading, is the fact that all aftermaket parts for our cars have been created from OE parts. How else do they fit within the original engineered design.

Darwantae951

My post was not directed at yours in any way, so pardon my confusion at what appears to be a defensive response.

The point of my post was that my clutch disc was a Porsche part, resurfaced. My PP was a Porsche part (951 part #) but tweaked for increased clamping. KEP and SPEC are not OE, which are two of the main set-ups discussed. I have no experience with Centerforce.

Chris White

I toss my 2 cents in on this thread –

First off forget the ‘torque’ ratings of a clutch – they don’t mean much and are quite arbitrary. A 100k mile stock clutch can hold over 400ft lbs if you are nice to it!
If you start making real boost with the clutch still slipping then you will have a hard time getting anything ‘normal’ to hold. If you like doing that then you are abusing your equipment….should have bought a different car.

I installed a Spec stage 2 set up in my old turbo – it lasted one week and I pulled it out. Very annoying. If you know how much work it is to change a clutch then you know how annoying it must have been to pull it out after only 1 week! I did keep the pressure plate but the disk was sold cheap!

It was replace with a cup clutch and that worked fine for years at 370rwhp/tq on the track.

The KEP / 930 combo may give you some problems – if your thrust bearing is worn you may not get the clutch to fully disengage – the disk is just slightly thicker than the 951 cup clutch.

Any higher clamping force pressure plate will wear your thrust bearing out quicker – and add more load to your release fork. Both can be problematic (and very expensive to fix!)

Southbend does a very nice job and will build a clutch to your specifications. In fact they are working on a disk for me right now that is a late model Ford Mustang disk with a 951 spline pattern – as I said, they will do stuff to spec!

ninefiveone

Late model ford mustang disk with a 951 spline pattern... this sounds interesting. What are you up to, Chris?

zerMATT951

Chris, I think you just covered my key points. I am not an equipment abuser... I completely understand the cost of hard launches, and if I wanted that, I'd buy a 4th gen Camaro to beat on and mod . I have fun at DE's, and my goal is to be smooth.

So after reading all of the comments so far, it seems like a Sachs PP along with either the 930 or Cup disc will be sufficient for my needs. On the other hand, if I upgrade my Super 53 to a super 61 or 75, or start increasing engine volume... I completely understand that I will likely need something with more clamping force. I just don't want to spend money where it's not necessary for my driving style.

I'd like to thank *everyone* who has weighed in with an opinion here. This is all very valuable information for me, and it seems like there are several others out there with the same question I have.

Scott H

Something crazy cool: https://rennlist.com/forums/944-turb...27-944-v8.html

Chris White

Crazy cool....yep, that covers it!

Adonay

I run a Cup clutch in my car how can i tell if it slip ? Go to the highway and floor the car in 5th gear and see if the revs increase to fast at max load? Anyways Before the engine went out of the car for the winter rebuild i think i have not noticed any slip. Even at high boost @ 5th gear.

racerxrick

I have 148k on the odometer and a whole pile of receipts. A numberof slave cyclinders over the years but no indication of a clutch rebuild. Assuming this is the original clutch...it's strong.

I only felt iit slip once and that was from abuse (slap shifted into 4th at WOT...even then recovered quick).

Still on the "to-do" list as I want to freshen that up and rebuild the TT.

Thinking KEP Stage 1 though with the 930 or Cup disc Matt? Hmm..then again look at how this one has lasted!

zerMATT951

My car has 176k miles on the odo, and I'm sure many more since it stopped working. I was told that a transplant motor was installed at around 162k, and I've got a whole stack of receipts too going several years back, and there is no evidence that my clutch is anything but stock.

My "stock" clutch has never slipped except for the one time I abused it trying to get a little extra boost off the line for one launch... I cringed the whole time and will NEVER do that again! After that, I really thought my clutch disc was on the way out (5+ years ago), but now the throwout bearing is headed south first. It's time to pull it apart, so it's getting a new clutch & PP while I'm in there.

I am leaning towards a stock Sachs PP and either the 930 or Cup disc... I can't quite convince myself to pony up an extra $400 for the KEP Stage I PP if I don't need it.

KSira

Why not use spec stage 3?

Bri Bro

I have been running that combo (930 disk) for over years and no problems. I have a lot more power in the new engine and the tire lite up but the clutch is still fine. I don't abuse clutches so I expect it to last for many more years.