vsomoza

My 2006 997.1 S (3.8L) is due for a new clutch and the performance shop I’ll be using has offered some interesting options including a Bully lightweight flywheel to replace the current dual mass unit. Does anyone have any experience with this?

They’re also suggesting a Bully Stage 3 kevlar/kevlar clutch to increase the clamping force by 400lbs.

We’ll be changing the IMS while we’re in there as well.

I’m looking for some thoughts, concerns and advise. Should I stick with a new OEM dual mass flywheel and OEM clutch or risk upgrading for some potential added noise and performance gains?

Thanks,
Vince

SoCal C2S

Will you be primarily tracking the car?

If yes, the light flywheel will help the engine wind up quicker and if you plan to really increase torque the upstaged clutch is a good plan.

If not, be prepared for increased interior whine from the light flywheel and if you don't plan any real increase in torque, the clutch you are contemplating will drive you crazy as they tend to grab abruptly so any street driving will be....well, an experience.

I did these types of upgrades on an M3 and after putting quite a few $ into performance it was a disaster on the street but a banshee on the track.

Saaboteur

This past summer, I had my clutch done. My complaint was that ever since I got it, once warm, I'd get a throw out bearing rattle. Drove me nuts. Picked up all new parts from another Rennlist member, including OE spec dual mass flywheel and OE clutch. After the shop had the trans out, I was informed that I had a lightweight flywheel in the car. That would explain the issues I had with low speed maneuvering. Once the dual mass flywheel was back in, the driveability was much improved. I don't track the car, so everyday useability is important to me.

Anyway, those are my thoughts on using both lightweight and dual mass flywheels. I'd also add why you would need or want extra clamping force on an otherwise stock engine (presuming it is stock and not adding forced induction)?

Fahrer

Why are you changing the IMS bearing? You should have the larger bearing in a 2006 S

vsomoza

Thanks guys. I appreciate you taking the time and relaying your experiences. This is such a great forum.

I was very concerned about the drivability factor so it looks like I’ll be going stock. It’s cheaper too. I like how my car can be very civil when driving my wife and kids around town and then a banshee when I take the long way home. I had my first track experience this past summer and I really enjoyed it and I will be doing it again but at the same time I’m not prepared to sacrifice everyday driving for some incremental increase in performance 2 or 3 times a year.

Thanks again, SoCal, Saaboteur

vsomoza

Are you sure about that Fahrer? No one can give me a verifiable answer on that. I’m only doing it for piece of mind and resale value reasons. But if you can point me to a resource that confirms that then you’ve just saved me some money.

Thanks,
v.

semicycler

Yes this is correct. Early 2005 997.1's have the smaller replaceable IMS bearing that was part of the class action lawsuit along with all the 996's. Later 2005 997.1's through 2008 997.1's have the larger, more reliable, but non-replaceable IMS bearing and were outside the class action window. Technically it can be replaced but the engine needs to be torn down and the crankcase split in two. Honestly your larger IMS bearing will outlast other failures on the car.

997.2's do not have an IMS so no IMS bearing.

cosm3os

I found the ltw fly in my old M3 was the most dramatic single mod that takes the car from street car to track car. Fun on track, but driveability, nvh suffer.

SoCal C2S

Yup....and that alone drove me to my 911. The very expensive way, but the scars on my back always remind me when I get the itch.

vsomoza

That’s great news semicycler. That puts my mind at ease. I do change the oil more often than suggested. The reason I still want to look at is because of this article. https://www.oregonpca.org/wp-content.../ORPCA-IMS.pdf

Schnell 911

How many miles have you logged? Just curious.

Schnell 911

Thanks for sharing "vsomoza" go read and a welcomed clarification, good stuff to know.

vsomoza

dgetz993, the car currently has 68,800 kilometres. Frankly, I was pretty surprise when the clutch stopped working properly. I was accelerating hard and shifting from 2nd to 3rd and the something happened. At the moment it feels like the pressure plate isn’t pressing against the flywheel properly. So it might be a broken spring segment or something. I guess we’ll find out soon enough. It’s going in on Monday to finally get fix. I’ll post pics of the worn parts and report back when it’s done.

Schnell 911

I am the Walrus

My clutch went and it was the pressure plate, I was told by the shop a known issue, (2006 997 4s)
Also, leave the IMS absolutely alone, I'm sure you you have the solid version, as previous poster mentioned.
Cheers