Got it, you guys shed some light on this for me.
So, to get my facts straight:
1) You can't lighten the factory dual mass flywheel
No. Dinan does and CNS does. The difference is Dinan takes some weight out ( I think about 8 lbs) and the stock DMF mates to the stock size disc.
CNS machines the surface to allow a bigger surface area and hence a bigger (10.5 inch disc vs. 9. 625 inch disc). I am not sure how much weight they remove. Where weight is removed is just as important as how much (removing less weight at the outside is more effective).
2) You can't resurface the factory dual mass flywheel (you just need to buy a new one instead?)
In the past conventional wisdom is you may be able to get a second use out of the DMF. If the clutch has overheated the DMF (the self adjusting mechanism is the issue here), then you are better off with a new DMF. If you have a ton of miles, you may also be better off. The price of the DMF has come down over time. If you are paying for labor, you want to be SURE the used DMF (after being scuffed up a bit) will work; otherwise it is cheaper to just buy new and be done with it.
3) Solid flywheel kits (i.e. UUC) are going to produce noise no matter what in comparison to a DMF?
That has been the collective experience here.
I've heard horror stories about the UUC kits anyways. Some people love them while other people hate them.
If you track the car and have increased the power, this is one of the best setups. You won't care about gear lash, and the system SHOULD be robust. My CNS 10.5 DMF seems robust also, holding up easily on the street with well over 550 hp. I have had no issues with it (although I have not taken the car to the track).
To me, an expensive car like the M5 shouldn't be chattering at idle or making noise from the flywheel, that just seems annoying.
That was my feeling. After all, this is a street car, and a luxury one at that.
From what I read about the stock M5 clutch it seems like a weak point and a bit 'under-designed' for this particular car.
Yes. It may have been intentional, as the weak link in a drivetrain that will fry a clutch before anything else breaks. But the 540, putting out about 115 LESS hp, uses the same setup. If you are running stockish power levels, and don't abuse the clutch (such as dumping the clutch from a standstill on a regular basis) , the stock setup (or southbend upgrade with no SAC and better PP) will do just fine IMHO.
Dinan Stage 3 suspension, SS jet coated headers, ESS SC kit w/ 1 range colder NGK's, 92mm pulley, 440 Big Greens, TTFS alpha N tune for meth, RK plenum plates, SBC Endurance Stage 3 Kevlar performance clutch setup, "Jed" lightened DMFW, open brake ducts, TEC cupholder, U.S.(Euro style) tilt/slide armrest, 6k HID fogs, Umnitza bi-xenon flamethrowers w/6k super white low beams, rear fogs, V1/Stealth1, dual head LI, 2.65 diff w/40% lockup/2x dynamic, compact spare, M5 logo trunk carpet, Euro trailer hitch, Mocal oil cooler, ACS type rear spoiler, Rogue custom SSK and tranny mounts, ST 355 BBK (fronts), BP sway bar brackets, Bluetooth retrofit, Speedhut boost gauge (20 psi), Dinan TB's and VS, KB BAP, Howerton/HFS-3 Aquamist WI trunk setup (50/50), with 2nd gauge in rear view mirror, aftermarket trunk mounted sound system integrated into stock unit (amps, crossovers, sub and speakers).......