<img border="0" title="" alt="[Eek!]" src="eek.gif" /> <img border="0" title="" alt="[Eek!]" src="eek.gif" /> This is a Cup Disk, only 3800 miles and no burn outs the second disk is a Kevlar unit from Markus Blaszak, maybe I will have better luck with it

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It looks like that disc wasn't running true inside the clutch (?)

 

Bet it was bent during shipping. That sucks man!

 

David, are you running the stock pressure plate? With your 2.8, it is my understanding that you will be generating enough torque to overcome the clamping force of the stock pressure plate. However, since the wear pattern on your cup disc is very uneven, this does not seem like a simple clutch slipping problem.

I have a Kennedy Engineered Products (KEP) pressure plate with greater clamping force that I am planning to use with a cup disc. Not sure if this will work but it is something that I am going to try. The four possible directions seem to be:

1. Stay stock and risk slipping
2. Upgrade the PP for greater clamping force with stock disc
3. Use the stock PP and change the disc to a more aggressive material that digs into the PP and flywheel better
4. Use both a higher clamping force PP and a more agressive disc

It sounds like you are going to try the #3 route. The aspect to watch will be the wear on the flywheel and PP from the higher coefficient of friction disc. I am wondering if this disc will put more wear on these parts?

The thing that bugs me is that none of this really explains why you experienced the uneven wear on the cup disc you removed . . .

Jeff

 

I think maybe the disk was damaged a couple months ago when the retaining ring for the throw out bearing popped off (at 1800 miles), I replaced the bearing but the disk looked ok, must have been bent.

Jeff, I also bought a 2275 lb PP from Markus to go with the kevlar disk, this set up is rated for 450 HP by Markus.

 

David,

Sorry to hear about your clutch troubles.

I was talking to KEP today and they say that the KEP PP with the stock friction disc is good for 536 Ft/Lbs torque. For interest sake the weight saving of the KEP PP is 11.25lb vs stock 15lb PP.

 

Regarding the KEP pressure plate, I agree with the weights you mentioned. When I weighed my KEP pressure plate and the stock one, I basically found the same weights you have described.

Another plus is that the KEP PP reduces the weight by using an aluminum "frame". This weight reduction is the furthest from centerline and, therefore, will have a great effect on reducing the inertial mass.

I am also using one of the Fidanza 5 pound aluminum flywheels, a crank that has been lightened by a reported 17 pounds, custom light weight rods and custom light weight pistons . . . should be fun!!

Jeff

 

What is the clamping force of the KEP PP ?

 

According to Brett at KEP, they have measured the following clamping force numbers:

* stock PP = 2,270 pounds
* KEP Stage 1 PP = 3,200 pounds
* KEP Stage 2 PP = 3,800 pounds

Jeff

 

What is the price of the KEP PP ?

How does it compare to the other guys' upgrades? Huntly, Lindsey, etc.

 

Seems we have some conflicting info

Markus says the kevlar clutch and 2275 lb pp is good up to 445 Hp and that the stock turbo pp is 1750 lb

Huntley site states the stock turbo pp is 2500-2700 lb

KEP tells Jeff, stock pp is 2270 lb.

Does Porsche list anywhere what stock pp is ?

 

KEP Stage 1 PP=$600

 

David, I agree that there are some inconsistencies in the data. I tend to want to believe the folks at KEP because all they do is custom clutch stuff. However, I begin to wonder if comparing clamping force from two different vendors is similar to comparing dyno runs from two different dynos (in other words, to compare "apples to apples" we can really only compare dyno results if they are all produced on the same day with the same dyno).

Following this logic, the relative increase in clamping force for the Stage 1 KEP PP when compared to the stock PP is 1,000 pounds. The clamping force increase with the Blaszak PP vs. the stock unit is 500 pounds. Maybe the relative increase in clamping force is the only thing we can learn from this data . . .

Jeff

 

The clamping force also depends upon the wear-condition of the clutch disc as well. Due to the arc in the swing of the springs, the clamping force will change. You can measure a 'clamping forc' figure at the surface of an uninstalled pressure-plate. You can measure it on the surface of an installed plate with a new clutch disc. Or measure it at the surface of a worn-out disc. Or the forc required to keep the pressure-plate fully disengaged by the hydraulics. All these 'clamping forces' can be different for the exact same pressure-plate.

 

What kind of clutch disc are those? None of theme looks stock to me (220 hp 3 250 hp 6 small center springs).
Why don't you use centerforce I thought this was the best aftermarket clutch, is it?