Hello planet niners!
About 2 years ago my 987.2S surprised me with needing a
fuel pump
, now time for the clutch! I would appreciate recs for the service in Houston, Texas area. Any good mechanics worth going to?
Do you know how much this can run? Also - would you do a light weight clutch? I’m more prone towards regular mass, but not 100% convinced…
Here is the troublemaker:
Many thanks!
If by light weight clutch you mean light weight flywheel, there was recently a pretty healthy discussion of this issue over on ********. Link below. My personal opinion is to stay very far away from anything other than the OEM flywheel. And clutch parts, if there is such a thing. The downside can be huge. The upside is minimal.
https://********.com/forums/987-forum/1392276-single-mass-flywheel-for-a-daily-driver.html
of course I meant the single mass flywheel 🤦🏻♂️
„Consider the fact that the dual mass flywheels that do fail may be failing because they are actually doing their job!!” - brilliant. I agree wholeheartedly. Thank you for sharing the thread. That ultimately solidifies my decision!
Might as well do water pump,
RMS, oil separator etc. at same time
AOS
isn't a big issue on the 9a1 motors. It would be prudent to do the RMS while you're in there though!
Koby Motors on Windswept replaced my clutch and dual mass flywheel in my
987.2
in late 2023. Shop is not much to look at, but owner is very knowledgeable and reasonable.
Also, my understanding is a dual mass is used because the internals are not precisely balanced. If you go to a lightweight flywheel (i.e., not dual mass) AND don't balance the rotating assembly, you will experience a myriad of problems as the engine ages. Remember the external harmonic balance on American engines? That's kinda of what a dual mass flywheel accomplishes.
RSS harmonically dampened underdrive pulley is a good complementary mod to this. The lightweight flywheel chatter does drive many people crazy.
OK, I have a Masters in Vibration Theory and I stayed at a Holiday Inn. In my view, folks tend to sell
Porsche
engineers short on this subject of dual mass flywheels. I can't prove it because I wasn't there when they designed this engine but I am pretty confident that when they looked at the vibration profile at the output of the crankshaft, they set out to precisely "dampen" the vibrations using a very scientifically selected flywheel. All engines have the same general issue. Each firing pulse generates a torque shock on the drivetrain. Additionally, each valve opening generates a torque shock on the camshaft, which transfers back to the crankshaft via the timing chains. Even if the engine was "balanced" to whatever degree of precision you can imagine, these torque shocks would remain. And over many millions of revolutions, there is a cumulative fatigue stress impact on the drive train. BTW 1,000,000 / 5000 rpm = 200 minutes of operation so yes, those pulses add up in hurry. I won't go into fatigue stress and endurance limits but anything that can be done to scientifically knock down the cummulative impact of these pulses is pretty much mandatory. So if you think you are smarter than a
Porsche
engineer, just remember- hubris cannot overrule the laws of physics or
Porsche
's internal design knowledge. Non-OEM flywheels on anything other than a no holds barred race engine? Don't!
BTW there has been a similar thread over on ******** recently where Jake Raby got very excited about what a bad idea it was to go with non-OEM flywheels. It makes an interesting read.
I changed to the lightweight flywheel in my 06 CS and it was terrible to drive. The guy I sold it to had it changed back to the regular weight flywheel before his had it shipped to him in FL. I was a Metro NY guy then.
Sorry to bring up an old thread, but what did it end up costing you? I am in the same boat.
A full clutch job is probably in the range of $2500-3500, perhaps more lately. Don't skimp on the parts - as others have said, use a new OEM dual-mass flywheel and also replace the throwout bearing, etc.
