Carl Fausett

PORSCHE 928 Performance Clutch Kit

Application: All 1987-95 Porsche 928 With Single Disk Clutch

Description: This complete clutch kit will solve any clutch slipping problems you've got! Ideal for racers and Supercharged Porsche 928 applications.

Where the stock Porsche 928 single disk clutch package has 1900 psi of clamping force, and the "Sport" option from Porsche provided 2100 psi of clamping force; this complete clutch kit from 928 Motorsports provides 2960 psi of clamping force, and yet still provides daily drivability with a comfortable pedal feel and quick engagement.

Designed to handle up to 650 HP without a problem.

Note the sprung center hub - working with the engineers at SPEC clutches, we were able to retain a sprung center hub so you do not knock your fillings out everytime you let out the clutch. Solid center plates are available upon request. Friction material is semi-metallic composite, and not overly-abrasive so it is kind to your flywheel.

Made from all-new components for 928 Motorsports LLC by SPEC Clutch, Inc.

Kit Includes:

• PORSCHE 928 Performance Clutch Kit
• New Hi-Clamping Force Pressure Plate
• New 6-Puck Performance Clutch Plate
• New Throwout Bearing
• New Pilot Bearing
• Clutch Alignment Tool

AO

Better post the price.

Carl Fausett

$895.00 for the complete kit for 1987/88. $995.00 for '89 thru 91; $1095 for 92-95 models.

BC

I don't recall any differences in the 87 and 89 cars in the clutch area.

Are these higher or lower in thier streetability compared to your dual disk high performance stuff. The 87 up flywheel is quite heavy - and that is part of the reason I like the dual disk. And iwth your dual disk high power handling kit, it would be good.

How were you planning on handling that Carl? Thanks.

Carl Fausett

Basically, we are re-tooling our clutch packages.

My last machinist/supplier did good work, but was unreliable and never hit the delivery dates we agreed on. I fired them.

We have just gotten in bed with S.P.E.C. Clutch and Flywheel and I look forward to a far more professional relationship with this supplier. These guys are pros, and I am delighted to add SPEC to our 928 product line.

In our agreement with them, they have agreed to keep 3 of each 928 kit in stock and on the shelf for us!

To answer your single-disk vs twin-disk question: . The new twin disc setup we will be offering will hold 750+ ft lbs tq.

I am out of time to post the twin-disk setup today and will be posting it on Monday or Tuedsay when we get back. I'll get you pics as soon as I can.

The current twin-disk clutch setups on our website are coming down and will be replaced with these new complete kits.

I think the "kit" is the way to go - actually the price is lower to you this way than buying all those parts (throwout bearing, pilot bearing, pressure plate, clutch) separately.

BC

good ideas Carl. Still going with the replaceable wear areas on the lightweight flywheel?

Same with the later cars? Weight differences? (The only reasons for the early clutch was weight and power handling - so I think you've changed the playing field if it all works out)

AFARR

My '84 is an auto. However, a question:

For NON-S.C. or Turbo cars (i.e. standard US or Euro engines), will the installation of a "heavy duty" clutch like this extend the life of the clutch if driven normally?

Thanks!!

AFARR

Carl Fausett

Yes, maybe. But this is hard to say for sure, we have no stock 928 we can point to that has put 100,000 miles on a performance clutch, so my answer is guess-work. If driven normally - as you say, on a normal motor, the Porsche clutch packs are quite good.

However, the performance clutch disk use semi-metallic friction materials which are tougher and more durable, and because the clamping pressure is higher, they hook up quicker and slip less. For these two reasons, I think it would last longer.

But again - I'll sell you one if you want it, but if your motor is all stock and your application is all normal daily driving, not sure that the extra expense is warranted.

Jim bailey - 928 International

Clutch disc material is somewhat comparable to brake pad material. The harder the brake pad generally speaking the more potential there is for wear of the brake disc. The harder the clutch material the more potential for wear on the flywheel and face of the pressure plate. The advantage of a higher pressure pressure plate is increased clamping force which should reduce slippage after the clutch is engaged. The release bearing which connects the clutch arm (which does not spin) to the pressure plate bolted to the flywheel (which spins) is working spinning all the time the engine is running but when you push down the clutch pedal the release bearing pulls back on the spring fingers of the pressure plate and the bearing is subjected to very high loads. That is why to extend release bearing and pressure plate life it is best not to hold the clutch pedal down while waiting in line for a Starbucks Grande double Mocha... Higher clamping force by necessity means more clutch pedal effort . My old 911 runs a triple puck metallic clutch and very heavy pressure plate but I converted it to hydraulic master and slave cylinder. It is so harsh (no spring center) that it is either in or out and is very difficult to start out from a standing start compounded by the lack of torque of the big cammed 2.8 liter engine. Like just about everything about a car the choice of clutch materials is a compromise. However if the power of your engine is overcoming the clamping force friction of your clutch assembly it is time to make a shift in those compromises since slipping underload quickly burns up a clutch ,damages the flywheel . Nice work Carl !

Carl Fausett

Jim Bailey's comments are spot-on.

The semi-metallics and metallic brake pads and clutch disks are harder on the flywheels and brake rotors - true. But, slipping clutches are harder on the flywheel than non-slipping clutches - also true.

That's why - in response to the question about the stock 928 doing daily driving, I just don't know if I'd recommend a 6-puck semi-metallic clutch setup. That would be over-kill, and the clutch parts would last longer, but as Jim points out, the flywheel won't.

But - I have had a few Murph 928 SC kit installations call saying that they are starting to get slippage in 3rd gear during WOT. All of these customers are 32v Stage 2 installs - so their clutches are seeing something like 480 to 520 ft pounds of torque to them.

I did not have anything for them, and as we had already developed a solution for our 200 mm twin-disk equipped friends - I thought I should get busy and develop an answer for our 250 mm single-disk friends also.

And then - I started reading DR's posts, and Mark Robinson's posts, and John Kuhn, and, and, and.... I thought I better get my but in gear as the market for some Heavy-Duty clutch parts should be looking pretty good pretty soon!

AO

Smart man....

FlyingDog

Will your new dual disk kit similar to your current dual disk kit or more like the new single disk? The current dual disk kit doesn't look like it has sprung hub(s), will the new kit be sprung?

Jim R.

Nice work Carl!

I think I'll be needing one of those single clutch kits this winter. The Murf stage 2 power levels can definitely abuse the clutch with a real hard shift to 3rd if you have some sticky and wide tires. With just a firm shift(lift throttle), no issues. I was hoping not to have to change to a twin disc setup, so this is perfect.

Jim R.

Carl Fausett

The re-desgned twin-disk clutch I am going to be announcing soon will have your choice of sprung center hub or solid center hub.

Herr-Kuhn

Good Work Carl! Do you have torque specs on these single disk units?