Grabby clutch that's worse on warmer days than cool days. Flywheel hot spots?

[McGuillicuddy]

My ALH is Malone Stage 2 with DTP 520 injectors. I have an IDParts Quiet Clutch kit installed (~ 3yrs and about 50K kms ago) and it holds the power no problem. However the engagement is often rough as I am releasing the pedal and the engine is taking on the load of the vehicle. But it doesn't happen all the time. On cool days and when the vehicle hasn't warmed up the engagement can be quite smooth. But on warm days, or after the engine is warmed up it gets grabby to the point where it is very difficult to get a nice, smooth takeoff (going either forward or reverse). Is this likely to be hotspots on the flywheel? I don't know how they would have gotten there - I am a *looong* time manual driver and I am very gentle on the clutch. I don't ride it, I don't launch the car, I rev match on almost every downshift. Could it just be that this was a low quality flywheel that got hotspots from normal usage? Or might this be caused by something else?

It's not a huge deal, but it's one of those things that pisses me off and drags down my love for driving this car.

 

[Nero Morg]

It sounds like it. Rough engagement could also be a cracked pressure plate. Sounds like you gotta take it apart.

 

[McGuillicuddy]

It sounds like it. Rough engagement could also be a cracked pressure plate. Sounds like you gotta take it apart.

I would guess the cracked pressure plate would not have a temperature dependence.

 

[Nero Morg]

You'd be surprised. A buddy of mine had a 02 golf where the plate was cracked in 3 places. Shifted fine until it got semi hot, then it was absolutely miserable to drive.

 

[03TDICommuter]

Could it be that the coefficient of friction on the clutch disc changes with temperature by design? (like how some brake pad materials get grabbier when they heat up)

 

[McGuillicuddy]

Could it be that the coefficient of friction on the clutch disc changes with temperature by design? (like how some brake pad materials get grabbier when they heat up)

I'm sure the friction changes over the heat range, but if it's designed to get grabby and engage rough then that would be a pretty poor design choice.

 

[Nero Morg]

Usually it's the other way around, grabby when cold but smooths out when warm. Constantly grabby could also be oil or other debris on the clutch disc.