Is My Clutch Gimped?

[ukgatecrasher]

I have a 2002 996tt which has had a EPL flash and Miltek Exhaust for around a year.

The clutch was changed for a standard one by Porsche just before I got the car around 10k Miles ago.

I have never had a problem with the clutch even after the flash but a year or so down the line I now experience slip when on sustained full boost (1 bar) in high gears. This is most noticeable If I floor it in 5th / 6th Gear from a realtivly low speed so the high boost stays on for longer.

After experiencing the intial slippage and allowing boost to drop off the clutch does not slip again under any boost conditions. However the next day it will go back to slipping on the first occasion of high sustained boost then not slipping again till the next day.

I have not noticed any difference to the clutch bite or pedal position in the car since I got it around 18 months ago.

I had assumed that I would be requiring a new uprated clutch, and thought that it was behaving this way due to heat building up in the pads and maybe making them grippier after the initial slipping.

I would be inetersted In your more knowledgable explanations on why this is occuring and also your opinions on which uprated clutch to buy if thats the route I need to take. BTW I dont expect that I will be modding the car any further than this.

[sportsandclassic]

Hello,

What HP/Torque is your car now..?

[headlesshorseman]

ukgatecrasher said:

I have a 2002 996tt which has had a EPL flash and Miltek Exhaust for around a year.

The clutch was changed for a standard one by Porsche just before I got the car around 10k Miles ago.

I have never had a problem with the clutch even after the flash but a year or so down the line I now experience slip when on sustained full boost (1 bar) in high gears. This is most noticeable If I floor it in 5th / 6th Gear from a realtivly low speed so the high boost stays on for longer.

After experiencing the intial slippage and allowing boost to drop off the clutch does not slip again under any boost conditions. However the next day it will go back to slipping on the first occasion of high sustained boost then not slipping again till the next day.

I have not noticed any difference to the clutch bite or pedal position in the car since I got it around 18 months ago.

I had assumed that I would be requiring a new uprated clutch, and thought that it was behaving this way due to heat building up in the pads and maybe making them grippier after the initial slipping.

I would be inetersted In your more knowledgable explanations on why this is occuring and also your opinions on which uprated clutch to buy if thats the route I need to take. BTW I dont expect that I will be modding the car any further than this.

i have the same problem 1994 964 3.6t modded to just over 400 hp it is a fresh engine that has a new clutch but exactly the same symptoms,slips once on full boost in 4 or 5th then does not do it again no matter how many times you try.

[Maersk]

Contaminated/binding gearbox input shaft spline preventing full engagement. Once warm the female spline on the clutch disc expands and allows free movement.

[ukgatecrasher]

sportsandclassic said:

Hello,

What HP/Torque is your car now..?

I have not had it dyno'd but 1/4 mile terminal speeds are between 122 - 126 mph tempearture dependant, which roughly calculates to around 500hp at flywheel.

[ukgatecrasher]

Maersk said:

Contaminated/binding gearbox input shaft spline preventing full engagement. Once warm the female spline on the clutch disc expands and allows free movement.

Is it possible to clean / rectify without a full strip down?

[thegoose]

Could it also be an RMS (or similar) leak that's getting a bit of oil on the friction plate causing it to slip after which it has burned off and is OK?

[Maersk]

Input shaft clean = engine out box separation.

[ukgatecrasher]

Thanks everyone, Looks like I'll live with it as its only a minor irritation.