997.1 C4 Clutch Slip, looking for clutch/flywheel kit

[Jimbowne]

Hello all,

 

I've got a 2008 997 C4 w/ 56k miles on it. It was cold this morning (30 degrees F) and I noticed clutch slip for the first time since I bought the car in higher gears under full throttle. The clutch pedal feels very mushy and lost alot of its spring on the return. I stopped by my local shop and he confirmed its the clutch.

 

The car is my daily driver but I do autocross about once a month and intend to track in the future. I told myself I'd get the light weight flywheel when its time to replace the clutch, and so it seems that time has come. I'm not adverse to the extra noise of the LWFW, but I've heard that you shouldn't do this mod on a C4. I see sharkwerks has a C4 project car with the LWFW so I assume it worked out, but who knows.

 

Aside from the flywheel obviously I need a clutch. I've been looking at the Sachs stage 2.5 performance clutch kit, and it seems like a good option. I've also heard that the BBI clutch slave cylinder is an upgrade that would be helpful for clutch performance and feel.

 

Questions:

-Anyone have any experience with a LWFW on a C4?

-Anyone have any experience with the Sach's stage 2.5 kit on a C4?

-Any other clutch kit recommendations?

-Anyone have any experience with replacing the clutch slave cylinder?

 

Note: I'm going to get my IMS bearing inspected but if its not leaking I think I'm going to pass, seeing how I have 56k miles on it with no issues. Perhaps its past the infant mortality stage?

 

Thanks,

 

Jim

[JFP in PA]

32 minutes ago, Jimbowne said:

Hello all,

 

I've got a 2008 997 C4 w/ 56k miles on it. It was cold this morning (30 degrees F) and I noticed clutch slip for the first time since I bought the car in higher gears under full throttle. The clutch pedal feels very mushy and lost alot of its spring on the return. I stopped by my local shop and he confirmed its the clutch.

 

The car is my daily driver but I do autocross about once a month and intend to track in the future. I told myself I'd get the light weight flywheel when its time to replace the clutch, and so it seems that time has come. I'm not adverse to the extra noise of the LWFW, but I've heard that you shouldn't do this mod on a C4. I see sharkwerks has a C4 project car with the LWFW so I assume it worked out, but who knows.

 

Aside from the flywheel obviously I need a clutch. I've been looking at the Sachs stage 2.5 performance clutch kit, and it seems like a good option. I've also heard that the BBI clutch slave cylinder is an upgrade that would be helpful for clutch performance and feel.

 

Questions:

-Anyone have any experience with a LWFW on a C4?

-Anyone have any experience with the Sach's stage 2.5 kit on a C4?

-Any other clutch kit recommendations?

-Anyone have any experience with replacing the clutch slave cylinder?

 

Note: I'm going to get my IMS bearing inspected but if its not leaking I think I'm going to pass, seeing how I have 56k miles on it with no issues. Perhaps its past the infant mortality stage?

 

Thanks,

 

Jim

 

I would stay away from the single mass flywheel for several reasons.  Noise and chatter are problematic on the street, and both Porsche an a renowned Porsche engine builder had recommended against using them unless the engine's rotating mass and the single mass are dynamically balanced together. People tend to forget the dual mass is the ONLY harmonic dampening device in the rotating mass, removing capability that can take you to places you don't want to be.

 

The upgraded clutch is also a toss up.  For heavy track use, it may have the advantage, on the street, not so much.  We have had customers run factory and replacement factory units with excellent street drivability and very long lives.

 

The BBI slave is another questionable.  Yes it changes the clutch pedal feel, but installations have be problem prone, including premature failures which the manufacturer continues to write off as due to the wrong fluid being used.  But multiple cases have shown that to not be correct.

 

As for your IMS bearing, while they are inspecting it, have them remove the rear seal so it can mist lubricate.  We have many running this way with no problems.

[CarreraLicious]

It’s a 2008, so it should have the larger bearing...is it possible to inspect the IMS without splitting the case? 

[JFP in PA]

2 hours ago, CarreraLicious said:

It’s a 2008, so it should have the larger bearing...is it possible to inspect the IMS without splitting the case? 

 

You can see it and feel if it has a too much play, but that is about it.  You can use a pick to remove the rear seal which is highly recommended.  You MUST however prep the engine as though you were removing it (locked at TDC, cams locked, tensioners removed, etc.) before pulling the rear flange to have a peek.

[CarreraLicious]

7 hours ago, JFP in PA said:

 

You can see it and feel if it has a too much play, but that is about it.  You can use a pick to remove the rear seal which is highly recommended.  You MUST however prep the engine as though you were removing it (locked at TDC, cams locked, tensioners removed, etc.) before pulling the rear flange to have a peek.

Good to know. Thanks!