fayence

I have about 13k miles on my car now and it seems I need to replace my clutch (started slipping). I was curious if anyone else has replaced their clutch yet?

1AS

This may be one of the key posts on this board. Please let us know the costs of this repair, as it has been a long-lasting concern. AS

W8MM

Wow. Sorry to hear that.

AFAIK, you are the first of the "normal" user base to report this on one of the boards.

FWIW, the Carrera GT tech at my dealer told me that his tech acquaintances have mentioned replacing a few clutches, but not many.

MANUAL

I wonder if the CGT clutch has adjustable shims like the carbon clutch on the McLaren F1. On the F1, the clutch can be adjusted a couple of times before it needs to be replaced.

fayence, did you ever find out why your transmission failed and what the total parts and labor cost was? Also, did the mechanic check the clutch for signs of wear before installing the new gearbox?

Now that the clutch is slipping, is it still easy for you to start off without stalling the engine?

Tool Pants

The clutch on this one was replaced twice within 3,200 miles.

PogueMoHone

Toolpants,

True, but there is quite the story behind it, so it's not really representative of expectations or normal wear.

Want to share it? Afterall, you raised the topic and intimated that it was not unusual!

I'm not at liberty to disclose the facts, except that it was an unusual circumstance.

Ray G

fayence, let us know how it goes. I heard that Porsche has covered (warranted) some clutch replacements on CGTs. Good luck on yours.

Holger B

The service writer at a local dealer told me they replaced a CGT clutch a year ago. IIRC, he said it had 4k miles and the cost was $20k.

ryanawesome

its all in how you drive the car. the pccc must be actuated like a like switch. on or off, none in bewteen. 6 seconds of slipping the clutch and its toast.

Thomas g.

That is correct. Unfortunately many current owners don't realize this, and I am not refering to the person above. I bought my car used with 1500 miles, a brand new clutch was put in my car by the last owner at 1500 miles. Porsche covered it under warranty.

W8MM

I'm not sure I completely agree with this statement, as currently written.

Six seconds is an awfully long time to be slipping the clutch in any car, and should definitely be avoided. However, if one were to operate the clutch exactly as described (on or off, like a switch), the car would be most unpleasant to drive. It would buck and snort on take-off and jerk around while trying to park.

I suggest a more thoughtful approach:

I allege that it's OK to slip the clutch a little bit during low-power maneuvers wherein the heat generated is quite low. One can't cook a chicken using only one kitchen match and one can't cook even a weird ceramic clutch by slipping it during a launch using NO throttle other than the engine controller's idle speed servo behavior. Ain't gonna happen.

Clutch damage comes from heat. Heat is caused by absorbing the difference in power between engine output and how fast the car is accelerating. Huge engine power output (big throttle) while the car is barely accelerating (high clutch slip) means all the lost power will be turned into friction heat in the clutch. Huge engine power and maximum acceleration means little slip and little heat for the clutch to adsorb. (For purposes of illustration, I am ignoring very high speed use where aerodynamic drag is the major power consumer. I'm assuming USA speed limit usage.)

The thing to be avoided is slipping the clutch when a great deal of heat might be produced as a result. In low powered cars, the engine can't easily produce enough horsepower to quickly fry any clutch. Only prolonged slipping (causing big heat build-up) can produce temperatures high enough to cook a conventional clutch in a car with a wheezy motor.

In the Carrera GT, the engine is so powerful that it is easily possible to generate enough heat energy to over-temp any style of clutch that might have been installed, PCCC or not. The PCCC has very good grab and doesn't fade (creep, slip) under high loads. But, once it gets too hot, it can degrade irrecoverably. So, ... don't get it too hot.

DO NOT apply full throttle AND slip the CGT clutch to modulate start-up from rest. This is like trying to cook a chicken with a blast furnace. Only the tiniest slip can be tolerated without real risk. The same can be said of using clutch slip to hold the CGT in place on up-hill grades while waiting for a traffic signal. Don't do it.

So, lets modify the no-slip (on/off switch) rule a little:

It's OK to slip the clutch a little when there is very little engine power being used. Just don't over-do it.

It's NOT OK to slip the clutch when the gas pedal is floored. Not ever.

Also, make sure that one's foot is not resting on the clutch pedal when using medium (or more) amounts of throttle.

1AS

How does 20K for a clutch sound compared to other exotics (exclude F1)? AS

Black Shadow

Clutch slipping produces friction which produces heat which wears out clutches (in a hurryif done at higher rpm's). Think of a bench grinder grinding against a piece steel, the faster the grinder wheel goes, the greater the friction and heat and the faster the steel wears down. Run the grinder at a slow speed and the steel will last much longer.
Do not slip the clutch at high rpm because like the grinding wheel, more material will be ground off. Low rpm start-ups is the key for long clutch life.

Ray G

Yes, I would agree with that. I slip the clutch a little all the time. I don't think I'm doing anything wrong.

In fact, the automatic throttle modulation feature (where you don't touch the throttle and slowly release the clutch) doesn't work on a hill, I've found.

Woodster

It works on a hill backwards, oddly enough!

MK