Does the clutch need replacing?

[adamt]

Dear all,

We took the turbo for a run on the autobahn and experienced some clutch slipping. What would happen is yuo gently and progressively accelerate until 1.2bar of boost and then suddenly the revs would flair out of control. I dont understand why this is happening because i was always under the impression when your clutch has problems it first shows up when you start to move the car from a standstill? And there is no problem whatsoever in this respect.

Thanks for any input, oh and the car has 55,000km

all the best
adam

>> Edited by adamt on Thursday 12th January 13:09

[jeremyc]

adamt said:

I dont understand why this is happening because i was always under the impression when your clutch has problems it first shows up when you start to move the car from a standstill? And there is no problem whatsoever in this respect.

Hi Adam

I suspect the clutch may be slipping as you get to the point of maximum torque being transmitted through it (at high boost). I'm no expert, but this seems a likely explanation.

I'm sure an expert will be along shortly ....

>> Edited by jeremyc on Thursday 12th January 13:14

[nel]

The first signs of clutch slippage on my turbo happened in longer gears (4th and above) when the full beans arrived. The shorter gears help the clutch to cope with pulling away, so it has to be REALLY shagged before you get slippage in the low gears.

[Raven Flyer]

Jeremy you are quite right. If a clutch is going to slip, it will happen in the highest gears (5-6th) and when the engine reaches a level of torque that exceeds what the clutch can resist.

Clutches don't slip in the lowest gears as the torque is turned into acceleration more easily (less load on the drivetrain). They don't slip at low revs or very high revs, as the torque is low at these engine speeds.

If its slipping, the wear rate will be going exponential and its life will be measured in hundreds of miles, not thousands. If you are not very gentle until its replaced, it will be miles, only.


>> Edited by Raven Flyer on Thursday 12th January 13:59

[rumplestiltskin]

1.2 bar ! X50's don't go this high....heavily modified then I take it ?

[Dakkon]

Hi Adam,

As the clutch gets worse you will see slippage work its way down through the gears, so its starts in 5th (or 6th) then 4th 3rd etc as it get worse, its the torque which is killing the clutch.

This is happening to mine right now, so still driveable, but I have to be gentle, goes in on Saturday to get a new clutch.

HTH

[verysideways]

Same problem with my 993tt when i switched to the RS ecu - as peak torque comes in using the first 3 gears there's no problem, 4th is sometimes okay, but i can guarantee that in 5th or 6th, if i start at 3k rpm and give it 'full beans' as the boost builds and the revs climb, just around 4200rpm (peak torque) i get slip (as you describe, the revs suddenly jump to over 5k but the car is accelerating less).

Time for a new clutch adam. Join the club

[adamt]

Thanks guys, yeah we will have it replaced.

rumplestiltskin said:

1.2 bar ! X50's don't go this high....heavily modified then I take it ?

Ruf R turbo, sometimes when its cold it will spike at 1.3 in 6th at 3,000rpm then will go down to 1.2 at 4000 and then settles at 1.1 above 5000rpm. Its fun!

all the best
adam

[mikereynolds]

Holy sh** that is a pair of fine Ruf's you have there!!

[Agent Orange]

Merely RS tuning and 551 bhp/798 nm..............but someone quite reputable was delivered an rs/ordinary turbo clutch for this last year and it was nt up to it 4500 in 4 th or 5th produced some very hairy moments ...........heavy duty Motorsports clutch all was / still is fine ,