joshd

My 05 GT3 is going to be partially apart for a trans and diff rebuild in the next few weeks. I'm wondering about doing a LWFW and (RS?) clutch upgrade at the same time. I mentioned it to my mechanic and his response was:

"I have a couple of GT3's with light clutches that go to the track. Performance wise it is a nice upgrade but for whatever reason Porsche doesn't recommend it on a regular GT3....I have yet to figure out why since they put that clutch in the factory RS cars which have the same engine (997 GT3). Anyway, the only problem we have experienced is that they tend to break throwout bearings. I have 3 different 996 GT3's running RS style clutches and flywheels and they have all broken at least one throwout bearing. They are all using the required factory throwout bearing. Also just had a 997 GT3 RS this week that broke its throwout bearing in the same manner, same throwout bearing. What happens is one of the release arms on the bearing will break an ear off."

Thoughts and recommendations?

Thanks,
Josh

AudiOn19s

I did catch recently over on the 997 GT3 section that Porsche is now officially frowning on the use of the single mass flywheel in non-RS cars. Like you, I don't get it as to the best of my knowledge other than the flywheel components and the crank pulley I don't believe anything is different between the two that would cause the single mass flywheel to be an "issue" in one car and not in the other. Could just be that Porsche is trying to have one more reason to deny warranty repairs.

I think most of the issues with the single mass flywheels is seen in the more powerful 3.8 RS cars where their different gearing leads to LOTS more shifting than we do with our long gear sets...and usually in those cars it's pressure plate related problems.

I have seen one or two examples of the "feet" breaking off of the throw out bearing. Don't know if that was a bad batch of them or something that is not designed to hold up to the stress??? Surprised your mechanic has seen soo many examples I've never really researched if there are other alternatives to that part or not.

One last note, some have attributed the harmonics and lack of dampening with the LWFW to cam bolts backing out on the newer variocam motors. Those cases have been isolated but there are theories that point back to the LWFW as a contributing cause. Thankfully that's specific to the newer fancier variocam designs and not the 996 cars.

That said, I've had a LWFW in my car for 3 years now with about 10k miles of combined street and track use. It doesn't chatter on engagement or have any bad behavior on the street other than noise and it's quite nice for rev matching at the track. I have a bit of a mix of different components in my car and I was worried about integration but it all works beautifully for me.

This is what is in my car:
- Flywheel from RS 4.0 (8.5 lbs) - actually it's a 964 part number it's an old cup car flywheel that Porsche pulled out of the parts bin and reused on the 4.0 street car
- Stock 996 GT3 pressure plate
- 996 GT3 RS 3.6 clutch disk
- Throw out bearing and clutch guide tube for LWFW - don't think there are any variations here...Throw out bearing has 928 part number I believe.
- 996 GT3 RS aluminum crank pulley

cfjan

No problem so far, but I have only had 1 season worth of usage. Installed the kit from the 4.0RS (LWFW, clutch, pressure plate, TOB, etc.) from Suncoast when the engine / trans were dropped for coolant fitting welding.

christallon

I have had no issues with mine and absolutely love it. The prior 2 owners never had an issue with is either. I think it's been in place on my car for 30K miles, so it's proven in my eyes! Revs are quicker, rev matching is awesome, sound at idle is fabulous, but I dig that sort of thing. I had read the problems were related to 997 cars and beyond, and have not heard of problems related to the 6-3. I would do it and enjoy the upgrade. It's super simple to engage and use, much easier actually that the one I had on my 964, which used the same GT3 clutch disk.

joshd

Thanks for the input folks.

Does this kit from Suncoast contain everything needed or is there more required to complete the LWFW/clutch upgrade?

http://www.suncoastparts.com/product//PKGT340CON.html

- Josh

joshd

Sorry, this appears to be the one they have listed for the 996 GT3:

http://www.suncoastparts.com/product...de=996gt3trans

cfjan

I provided that kit (bought from a fellow Rennlister) to my shop and they did the install. They didn't mention needing anything else.

I did ask them to install a lightweight pulley at the same time, however. I used the one from EVOms.

http://www.evoms.com/Porsche_996_GT3..._p/epk-gt3.htm

cfjan

The 4.0RS kit will fit.. !

christallon

Yes, It's all there. Both kits will work. I vote for the cheaper one

cfjan

Looks like the 4.0 kit comes w/ a new pressure plate.. partially explains the price difference.

The LWFW on the 4.0 kit is lighter also.

christallon

Interesting that the pic does not show pressure plate but descrition does. I would check with Suncoast to confirm, the cheaper one may come with the pressure plate, as the original PP wont work, as I understand it. Thanks for the details cfjan, the devil is in the details. Cheers!

AudiOn19s

Your original pressure plate will work with the new components, but as stated here it appears in the description of both kits. It's a wear item of sorts if yours has good mileage on it probably a good move to replace it too. I re-used mine but it only had 5k miles on it at the time of the swap

4.0 pressure plate is different from the 996 RS pressure plate as I understand it.

Also the 3.6 kit listed comes with the 3.6 RS flywheel at 11.5 lbs vs the 4.0 flywheel which is 8.5 lbs.

christallon

This board is an incredible resource. I appreciate learning something new every day. Thanks guys!!! Thanks Andy!

joshd

Thanks again for all of the input.

So it looks like the RS 4.0 kit is the better way to go since it seems to include the pressure plate ("Pressure Plate & Bolts" versus "Pressure Plate Bolts" ... very strategically missing the '&' or just a typo??) and the lighter part.

The EvoMS pulley is tempting too ...

christallon

I just called Suncoast to confirm. The pressure plate is not included with the earlier kit and is included with the 4.0 kit. Odd but true.