Jamie_GT3

Hi All,

I've been doing my research and it seems there isn't a great aftermarket option for us that will help to resolve the PP/TOB tango.

We've all done the upgrade dance (4.0RS PP, TOB etc..) and it seems even this isn't a complete solution as I've heard of a few PP issues already.

I'm looking for a good setup for the 4.2l and none seem to exist. I'm of the opinion that the current factory setup with a pull type PP/TOB is part of the issue. Moving to a push type with a hydraulic TOB may help this.

I've researched the titan Motorsports 3 disk Carbon/Carbon kit for the TT guys and it seems results are all over the map. Some guys getting 15k before having to adjust them, some getting one weekend. (very driving style dependent.) Talked to Aasco and they think they could do a single disk with push type actuation but best torque is around 500 or so (should be plenty for us NA guys, just wanted a little bit of headroom). Talked to JB Racing and they have some projects similar to my idea, but nothing finished.

If anyone can shed some light on WHY the PP's and TOB's are wearing prematurely on our cars, this would certainly help. Also anyone with a secret clutch/PP/TOB recipe, please share!

bimmer81

I have a Carbonetic triple carbon disc clutch that will handle anything you throw at it. It was removed from my 996tt with only 3k miles on the clutch. Lmk. Thanks

Jamie_GT3

What's the life on the disks and how readily available are replacements. Heard they're back in Japan, and not so many stateside...

Seems there should be something in between triple carbon and single organic...

Jamie_GT3

What's the life on the disks and how readily available are replacements. Heard they're back in Japan, and not so many stateside...

Seems there should be something in between triple carbon and single organic...

Ur20v

Its a mechanical failure of the tethers on the PP and the rivets on CP rather than wear per say. If you search some of the failure threads you will see what I mean

Jay

malmasri

You are partially correct, that issue was resolved with the 4.0 design, the clutch disc is not up for track heat so it is a weak link no doubt, No solutions yet, I may call PMS and ask if they have a carbon disc that will fit and holds up

M3EvoBR

Pressure plate is the problem and so is the trow out bearing, disc last a while with the new design around the springs.

Bottom line is for the amount of track miles those cars see, with people not rev matching properly there is not much out there that will resolve unless you go with a race clutch, which will compromise the use on the streets.

Jamie_GT3

And this is the issue

with 3 people weighing in we have

PP/Clutch disk
Clutch disk
PP/TOB

Says we really haven't gotten to the root causes of our clutch system weakness.

The problems I've seen are PP/TOB and believe the new 4.0 disk does resolve previous rivet issues...

Eddie, I've seen friends that do heel and toe and are not super hard on the clutch, still lose PP's. Agreed race clutch is a possible solution, but now we've gone from $1500 parts to $6000 parts! and we still have to inspect carbon/carbon pcs for wear and shim if wear is out of spec...

I know this isn't a new issue, how did the clutches hold on 993 and 996GT3s? Same issues?

24Chromium

My hub broke. Seems that the whole clutch design isn't up to the rigors of track abuse. Which is kind of strange, since the nearly identical car is produced as a factory race car.

M3EvoBR

Jamie you're right, I just mentioned about rev matching as this is a common issue even with experienced drivers.

The clutch design on the 996 is a little different, but only disc if I'm not mistaken ??

3.8-4.0 has more torque, engine revs high ... so a lot to consider.

Most of turbo cars with high power and good clutches are not used like the GT3s and also they don't rev as high as a gt3 so different approaches in my opinion.

Jamie, you can have a ceramic Cup clutch for 3500.00 instead the 6K for a carbon so that helps a lot

KaiB

I'd hate to be the supprised owner who mis-matches revs at speed with a new race clutch.

Jamie_GT3

Likely wouldn't work well on the street, this is the crux of it. finding a clutch that will play nice in traffic yet stand up to our track usage. I feel like I'm looking for a unicorn...

Agreed, not forgiving at all, and we would likely move the issue from the clutch to the gear box as race clutches aren't forgiving at all and from what I understand are quite hard on the drive train. Not to mention the possible money shift...

KaiB

It's very nice way to put the car sideways very quickly at a terrible place to do so.

TRAKCAR

I'm sticking with the OEM 4.0 stuff. It wont last forever but long enough for the $2500.

Izzone

Agreed pressure plate is the problem....even the 4.0 pressure plate is weak and moves. Once the pressure plate is weak and not centered perfectly the clutch starts to take the abuse of no disengagement

The 4.0 clutch still fails, maybe it holds on longer but my last failed clutch cracked at the springs again, the springs stayed in tact thou