47 replies to this topic

[Acidpopstar]

Can of worms this one... John found why I had no drive. Clutch is in bits! This is the clutch that came with the forged engine from Lee’s car so it’s had a hard life I guess.



What to replace it with though. Hope to fit a smaller pulley soon and aim for 300bhp.






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[smiley]

[Acidpopstar]

I’ve barely driven the bloody thing! Managed one lap of Spa Sent from my iPhone using Tapatalk

[CHILL Gone DUTCH]

You should of bought a new clutch when the engine was fitted

[vocky]

Helix clutch too

[Rosssco]

C20LET clutch (which may be the same as the Helix..)

[Johnboyhgt]

Let you guys make your mind up on the helix / C20LET issue.
All I will say is I put a LET in mine !

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[Acidpopstar]

Helix clutch too

Is that supposed to be able to handle more power than standard Vocky? Is it the same as the C20LET? Sent from my iPhone using Tapatalk

[MartinS]

When my car had around 270bhp it had the uprated courtenays clutch fitted (VX rated for 270-320), but that literally fell apart within a few thousand miles so I really wouldn't go near that, especially as a most of that mileage it had had little hard use. It went while on its 5th trackday on a straight not even changing gear, Lee had never seen anything like it.

I then got the even higher rated one that's called the competition clutch and rated as good for 350-375bhp. The pedal movement wasn't too bad.

Martin S

 

[Rosssco]

 

Helix clutch too

Is that supposed to be able to handle more power than standard Vocky? Is it the same as the C20LET? Sent from my iPhone using Tapatalk

 

 

There was a 'rumour' that the CS uprated clutch (Helix, I think) was just a standard C20LET clutch with the P/N removed. Although your clutch disc looks like different material, so who knows..

 

Like anything, if the clutch has been subject to high use and loading through the likes of regular trackdays, it will wear at a greater rate and fail sooner.

 

Ignore nominal power ratings banded about, engine torque is the larger factor.  

Edited by Rosssco, 12 January 2018 - 09:17 AM.

[Acidpopstar]

Thanks Martin I’ll look at the competition clutch. Any other recommendations? Sent from my iPhone using Tapatalk

[smiley]

I use the fast road and it slips on agressive use with 280 hp. So definitly not that one.

[siztenboots]

Helix clutch too

 

unusual failure

 

unless used for drag racing perhaps

 

probably get away with another helix friction plate 

[siztenboots]

I am still not convinced what broke the clutch , but flywheel energy has sheered the metal , whilst input shaft resisting the force. Does the gearbox move freely , or does the diff move without trying to pop out driveshafts.

 

Can't tell from the photo , but in good light you should be able to see the metal fingers (diaphragm) on the cover plate if they have been heat treated.

 

[Acidpopstar]

I use the fast road and it slips on agressive use with 280 hp. So definitly not that one.

Yeah I’ll swerve that one as Martin seems to have had issues as well. Lee says it was the Courtenay competition clutch (just below paddle clutches) that he fitted. Considering they are rated to around 370 (?) I’m debating whether to get the same one again. Certainly won’t be doing any drag races and max power will eventually be around 300. Sent from my iPhone using Tapatalk

[Johnboyhgt]

I am still not convinced what broke the clutch , but flywheel energy has sheered the metal , whilst input shaft resisting the force. Does the gearbox move freely , or does the diff move without trying to pop out driveshafts.

 

Can't tell from the photo , but in good light you should be able to see the metal fingers (diaphragm) on the cover plate if they have been heat treated.

 

 

The clutch friction plate has failed in rotational shear, you can see the rivets are all in place and the holes have simply opened up around them, so put simply its either torque that has opened them up or a wheel has lifted and the sudden finding of grip hence resistance has caused it.

 

Other possibility is that Lee likes to do drag strip work so it could be fatigue over time that has led to the failure.

 

The diff is in operational condition, my first thought when diagnosing was that the diff had let go as with one wheel in the air, engine off in gear there was no resistance to rotation - never thinking that the clutch was in two parts. the pedal operation was smooth and there was no grinding at all.

 

John

[siztenboots]

I have seen a borg beck elise s1 clutch fail in the same way , ie. rivet failure

 

They have very little torque, but what I was trying to say was I don't believe prolonged torque force is the problem , until the friction plate itself is the part unable to rotate. The inner springs will dampen some abnormal shocks , but if they have reached their limit, then the rivets are the next thing to go.

[Johnboyhgt]

I also think the driveshaft popping out is a red herring, the new clip I fitted prior to finding out about the lack of drive certainly works well. Had a right chew on getting the shaft out again !

[Johnboyhgt]

Im just trying to find a link here between the driveshaft popping out and the clutch starting to fail and then i will be happy. its a bloody heavy box and I don't want to take it out again.

 

 

[CHILL Gone DUTCH]

That clutch hasent started to fail it's had a sudden failure