12-03-2012, 11:58 PM
Join Date: May 2008
Location: San Francisco, CA
My Ride: 2000 323i
| Sweet! Thanks Ian!
Hmmm... good point. Well, I cant really speak to this issue with any authority other than my experience. What I can do is pitch you some of the arguments I made with myself when deciding on doing this clutch swap.
Originally Posted by Ian@BavAuto
Alex, sorry for the delay in a response, we had to get one back in stock.
Flywheel - 23.60 lbs
Pressure Plate - 10.10 lbs
Clutch Disc - 3.75 lbs
Unfortunately, I didn't have a stock Dual-Mass flywheel to compare to.
Hope this helps guys.
On the one hand, you can always argue that BMW put part 'X' in their cars for a reason. Which is a great truism and a good catchall when you're unsure about how to proceed with a repair/mod. There is always a trade off when you modify a vehicle. There is also something to be said for the general movement within the automotive industry to stop using single mass flywheels and replace them with dual mass flywheels. And you cant ignore the benefits of having 100% elimination of gearbox chatter and notichy shift lever engagement.
On the other hand, BMW engineers don't always put part 'X' in their cars for the right reason. Any e46 fanatic worth his salt can point out 10+ poor engineering choices made with the e46. These things crop up because engineers are constantly having to make a deal with the devil. Sometimes they choose parts for political reason, sometimes for time reasons, sometimes for cost reasons, and sometimes its because they're a mediocre engineer and are flying under the radar (it happens). Additionally, they have to make their cars function just as well for the grandmas of the world as it does for the Mario Andretti's of the world. It has to be able to get submerged in several feet of water, survive arctic winters, and desert climates. Curbs, car accidents, crazy ex girlfriends, acid rain, etc. In the end, its up to the owner/user to decide whether or not the car meets their needs and whether or not to personalize their car.
Anyway, back on point, I honestly think that auto manufacturers are installing dual mass flywheels for fuel economy reasons -not for gearbox longevity. Manual transmissions are famous for long life and absurdly low maintenance. But fuel economy is an area of improvement all cars can benefit from. And right now all the automotive manufacturers are trying to boost their fuel economy numbers. I just cant imagine a scenario where the project engineers would choose to make an already hyper-reliable part even more reliable.
If you're still on the fence I suppose you could ask the lightweight flywheel guys. They'd be a great gauge for longevity and reliability -especially since they'll be more likely to be beating up their transmissions -haha! You could also email/call ZF's technical department and ask them.
Hope that helps!
Originally Posted by Redryan98
Great info! I'll be doing a clutch job in the spring and may consider this set up. One concern though, is that in the original post you mentioned some gearbox chatter (albeit a small amount) and than you later go on to describe how damaging chatter could potentially be over the long run. Are you thinking that its such a small amount that it won't have any negative long term impacts?
Last edited by alexxander.foster; 12-04-2012 at 12:01 AM.