Dynamic Clutch Balancing

[MTstig]

Hello all. I have a 2002 Boxter S with a Jake Raby/Flat6 Innovation's engine (3.6L) with about 20k on the rebuild. I had an unusual clutch failure and need to replace it. I've been told, by Flat 6, that I need to have the new clutch kit dynamically balanced. There's so little info out there on this process that I'm wondering if this is overkill. Your thoughts please.

[JFP in PA]

It is worthwhile.

[997_986]

It is unclear to me what the general overhaul of the engine should have to do with the clutch and why the latter should necessarily be dynamically balanced, although frankly it is not clear to me how this should be done with a mounted clutch inside the car?! Millions of cars drive around with clutches that are statically balanced at the factory. I have never heard of a clutch unit that has not been dynamically balanced leading to engine damage. Vibrations and leaking seals would be first in line.

Buy a high-quality clutch unit and you're done!

[Gilles]

IMHO, you should send a new flywheel and new clutch assembly to get them balanced together

[JFP in PA]

Originally Posted by 997_986

It is unclear to me what the general overhaul of the engine should have to do with the clutch and why the latter should necessarily be dynamically balanced, although frankly it is not clear to me how this should be done with a mounted clutch inside the car?! Millions of cars drive around with clutches that are statically balanced at the factory. I have never heard of a clutch unit that has not been dynamically balanced leading to engine damage. Vibrations and leaking seals would be first in line.

Buy a high-quality clutch unit and you're done!

Don't bet on it. We have seen multiple top quality clutches and flywheels that were no where near balanced right out of the box, and as these engines have very little in the way of harmonic dampening, that difference can cause some large issues.

[MTstig]

I reached out to Flat6 shortly after my clutch failure (Flat6 clutch had < 20k) and was told the new clutch must be dynamically balanced. There must be several hundred thousand flat six Porsches in this country that at some point need a clutch replacement, but there is so little information and few shops that perform that service. Patrick Motorsports, in AZ, dynamically balance every clutch kit they sell.

Intuitively, I think the vast majority of clutch kits sold for these cars come right off the shelf! Would you agree?

[JFP in PA]

Originally Posted by MTstig

I reached out to Flat6 shortly after my clutch failure (Flat6 clutch had < 20k) and was told the new clutch must be dynamically balanced. There must be several hundred thousand flat six Porsches in this country that at some point need a clutch replacement, but there is so little information and few shops that perform that service. Patrick Motorsports, in AZ, dynamically balance every clutch kit they sell.

Intuitively, I think the vast majority of clutch kits sold for these cars come right off the shelf! Would you agree?

Just because a new aftermarket part is sold does not mean it is in correct balance. We have seen brand new aftermarket flywheels (non Porsche) that were more than 20 grams out of balance.

[MTstig]

I finally received my balanced DMF & pressure plated from Flat 6 and installed it yesterday. Throughout this project, I've learned as I've gone, so to speak and yesterday was no different. I used new Porsche flywheel bolts, torqued them to 19 ftlbs and then began to torque them to 120 degrees. I used a Harbor Freight digital wrench for the first time and my inexperience resulted in some inconsistent readings. Should I be concerned if the the flywheel bolt's torque, range from, say, 112- 121 degrees with one possible as low as 100?

[997_986]

Not really.
Did you notice any difference after the the "new" balancing, like removed material or marks whre they drilled?

[MTstig]

I've just installed the flywheel. Probably a week before it's back on the road. I'll report back then. Thanks.

[MTstig]

Sorry 997_996, I miss understood your question. Yes, grind marks on the pressure plate and drill holes on the flywheel.