997 Turbo glitch

[flat6]

Hi All

I'm thoroughly enjoying my 997 turbo. Every drive is exciting and involving. It's a 2006 manual with 12000 miles. At the weekend I was driving on the motorway and the car performed faulty except for one glitch. On on occasion when I tries to accelerate in 6th gear it didn't do the usual surge forward as the turbos kick in, instead the revs shot up with no acceleration as if the clutch had slipped. I quickly got off the throttle, so the revs didn't go beyond about 4000 rpm. I tried to replicate it a few times, flooring it 6th gear at fairly low speed, but it accelerated normally every time with the turbos coming in and sending the car forward without any rev mis-match.

Any ideas what happened?

Thanks

 

[Alex L]

Did you smell burnt clucth at the time or after you stopped?

I use to get this a lot (especially in colder weather when you get more boost) when my stock clutch was worn out. I upgraded to a Cargraphic clutch and all good since.

Has you car been remapped to give more than 680Nm? If so it may need an aftermarket clucth as the OEM pressure plate cant handle increased torque.

 

[garyw]

I very occasionally had this happen on my 2006 car.
However it did have 45k miles on it[]

It was always in similar circumstances to what you describe and just lifting off or doubling the clutch solved the problem.
I assumed it was just the friction material not having the chance to bite correctly or me having gently caught the clutch pedal at some point.

 

[flat6]

Thanks Alex.

Come to think of it, I think I did smell a bit of clutch when I parked up about 50 miles later. The car should be stock map and clutch, bought from an OPC in May. I've put about 1000 miles on it since. It seemed strange that it happened in top gear and cruising because I do give it some welly in lower gears and higher revs and so far so good. Then again, with that flat torque curve, is lower revs and peak torque more strain on the clutch...

Do you think I should have the clutch looked at now or keep an eye out for it re-occuring?

 

[flat6]

Thanks Gary. I've just googled double clutching so might not fully understand it. Is that only for downshifts? I haven't yet dared to do an aggressive downshift lol. Still getting used to the massive performance hike over the Spyder []

 

[Alex L]

ORIGINAL: flat6

Thanks Alex.

Come to think of it, I think I did smell a bit of clutch when I parked up about 50 miles later. The car should be stock map and clutch, bought from an OPC in May. I've put about 1000 miles on it since. It seemed strange that it happened in top gear and cruising because I do give it some welly in lower gears and higher revs and so far so good. Then again, with that flat torque curve, is lower revs and peak torque more strain on the clutch...

Do you think I should have the clutch looked at now or keep an eye out for it re-occuring?

Tricky one - clutch is under "wear and tear" so wouldn't be covered by warranty - otherwise I would say to definitely get your OPC to look at it. I don't know if clutch wear is on their 111 point inspection - probably not given how inaccessible it is (it took 6 hours labor I seem to recall to change my clutch). But as Gary points out, the clutch should not be slipping at such low mileage.

Perhaps you just didn't push the clutch pedal down enough when you changed gear? I recall burning my stock clutch badly in Switzerland when reversing slowly up a hill and riding the clutch a little.

6th gear at low revs is going to put max strain on the engine. Were you in sports mode at the time? ie. over-boost? Before my remap I use to only get 0.9/1.1 bar (normal/sport). After the remap it went to to the full 1.0/1.2. Obviously 1.2 bar in 6th at low revs (on a incline too I suppose) is the biggest strain on your clutch...

 

[garyw]

ORIGINAL: flat6

Thanks Gary. I've just googled double clutching so might not fully understand it. Is that only for downshifts? I haven't yet dared to do an aggressive downshift lol. Still getting used to the massive performance hike over the Spyder []

I've perhaps described it incorrectly, but simply re-engaging the clutch in and out was more than enough to solve the issue when I had it, it was always in higher gears and not in the lower more expected ones...

 

[flat6]

Thanks guys. Sounds like you have had the same thing. It was nearly 2am so my memory is sketchy but I think I had come out of a 50mph restriction and then hit an uphill. I was definitely in sport mode. I was already in 6th so didn't change gear when I accelerated so it was strange when the revs shot up as if the clutch slipped. I lifted off and reapplied the throttle and all was fine. Tried to replicate it but it performed correctly.

Based on what has been said, if it doesn't happen again, I'm wondering if my sleepy left foot might have rested on the clutch. If it happens again I might have some clutch wear or I just need to be sympathetic with a lift off of a clutch disengage if I'm putting the engine/transmission in a high strain scenario.

 

[okellyt]

If you cant smell clutch after you've driven it for a while your not trying hard enough. A well driven turbo always has that wiff after a hard run.

As Alex and Gary say it would be unlucky for you to have a problem with such low mileage. f it happen again make a note of what you were doing/how you were driving at the time and prior to that on the journey - see if a pattern emerges.

 

[flat6]

Will do. Thanks[]

 

[tscaptain]

ORIGINAL: okellyt

If you cant smell clutch after you've driven it for a while your not trying hard enough. A well driven turbo always has that wiff after a hard run.

I would think that a clutch is only designed to slip while pulling away from a standstill. If driven properly, including bringing up the revs on downshifts, why should it slip?