Jerseybean

I just had a light weight flywheel install. When the car is in neutral with the clutch out it sounds like a coal miner digging underneath my car. The car runs fine except for that one issue.

This sound is extremely similar to a problem that someone else is having on the 964 board. Do I need to pull the engine, is this a throwout bearing issue?

Here's the sound from the 964, it's exactly the same sound as mine has - popcorn maker!!
http://homepage.mac.com/guessendo/bad2.MPG

GT3 Chuck

the stock flywheel is a dual mass...it is normal to have gear noise in neutral with a single mass (lightweight) flywheel. It's part of the charm of a race car...

Jerseybean

NJ-GT said the same thing. I had a LWF in my 964 but never had this noise... I guess on the cup cars it must sound even worse.

Jim H.

Doesn't sound good to me. Not even charming. Can someone confirm the 964 clip is what you get with the LWF in a GT3?

Thanks.

GT3 Chuck

Jersey...you might want to do a search...there are many on this forum who have done the lwfw and some complain about the noise and others don't think it is too bad, but they all have noise compared to the stock dual mass setup...you might want to pm Sloth since he has a lwfw and has a good idea of how much noise there should be. Here is a quote from Sloth (by the way it is not the flywheel that is rattling but the gears in the tranny):

I would not have bothered with the upgrade until I had a reason to drop the engine. Luckily the RMS gave me the reason, PCNA picked up the labor, and it was a no brainer decision as a "whilst your in there" upgrade. The GT3 already makes plenty of noise on its own and the additional rattle of the flywheel is not a big deal to me. The rattle is only heard at idle with the clutch out or when pulling away from low RPM's (ex: 2nd gear at 12mph). I knew before hand I was going to get some noise, but its not as loud as I was expecting. Your tolerance for the sound may not be the same as mine, so a test listen is a good idea if your concerned.
__________________
HWFM Racing- Official "Team Rolling Chicane"

20C4S

have the same sound in the CGT although it's not this loud. like Sloth said ''The rattle is only heard at idle with the clutch out or when pulling away from low RPM's (ex: 2nd gear at 12mph).''

Adrian

Jim,
Depending upon which option combination selected determines the combination of the parts required to make the LWF system work.
The LWF used is the 964 RS unit, but the rest of parts for model year 2004 GT-3s and up are a combination of 996, 950 and 944 part numbers. The throw distances vary slightly.

As a general point the DMF is used to reduce internal noise to meet regulatory requirements. When the DMF is replaced with a LWF so does internal noise.

The sound on the posted file sounds like the thrust bearing eating away the guide tube. I have seen this many times before when the incorrect combination of components are used. Most commonly the guide tube and thrust (throwout or pigot) bearing.

My advice is to always ensure the correct parts combination is sourced to achieve the correct result. The guide tube and the thrust bearing being the two that can cause these horrible sounds.

The Porsche parts catalogue for the GT-3 provides this information and the combinations required for options M002, M003 and M004.

For the record this first happened to me on my first Porsche (924) way back when Moses was a lad. Same noise and it was an incorrect thrust bearing used for the racing transmission conversion.

The problem on the 964 forum turned out to be the wrong flywheel bolts being used. The parts catalogue for the GT-3 shows that the same bolts are used for the LWF and DMF. However after suffering a flywheel come off (Ford Escort RS2000) when the flywheel bolts were incorrectly torqued, it would be worth checking that the flywheel is sitting correctly.

Ciao,
Adrian.

DanH

Just to confirm that the sound sample is not how a LWF in a GT3 should sound. It's a much quieter rattle than that.

stevewashburn

I would call Austin at Devek and confirm what part numbers they use in their conversion kit for the LWF as compared to the parts you installed. My LWF installation went perfect and has been problem free, with only a modest increase in noise at idle. I know Devek has sold numerous kits which have been successfully installed. Good luck.

ShockDoctor

Jerseybean

I purchased the LWF from Austin.

roberga

that sound is not what I have. There seems to be an additional higher pitch rattle in addition to the normal sound. The normal is loud however. The first time my wife got in the car she ask "what si the noise, is something wrong with the car?"

Jerseybean

So in neurtal with your clutch out you get the popcorn sound right. I'm just very concerned that I might have to drop the engine again.

Jerseybean

I just took the car out for a quick trip, the noise doest happen when the car is cold, only after about 6-7 miles does it act up and start making the popping noise?

roberga

I do not know how to discribe it. I know when I first got may GT3 there were all kinds of sounds that were new to me. Lucky for me we have about 10 GT3s in the area and I was able to compare at the track and Autocross the sounds. Mine are normal.

That would be worth doing. Is there anyone that can help this guy?

roberga

jersybean: I can send you a video with a RS motor sound. This sould be pretty close to what yours should sound like. Provide me with a PM address and I can send it. It is a quicktime file.