"I’ve always been weary of lightweight flywheels and was anxious to installing this considering the labor involved.
After all is said and done, this is arguably one of the best modifications I've done to my S65 DCT.
Tolerances vary, read and listen carefully! "
My first test drive.
On my first test drive, I thought the clutches & flywheel were slipping off each as it was so much faster.
Maybe tires were too.
I unwillingly hit the 8,600 limiter a few times, catching another gear much faster than it used to.
It fixed a common complaint about the sluggish mid range of these engines.
It drastically improve the DCT’s shift operations; everything happens quicker now with no added jerkiness.
No tune or adaptations needed.
I had a JB racing aluminum lightweight flywheel and Sachs Heavy Duty clutch on the E46 M3. I like to say it’s like dropping a bucket of bolts in a blender at idle.
How it sounds.
The TTV flywheel is a single mass design milled from carbon forged steel.
It’s higher density than aluminum, commonly used by other brands.This allows is to be machined to a tighter package, further limiting rattles.
This is an unedited clip to show the true, sound and effects the TTV flywheel has on the S65 & DCT.
I can only describe it as a slow, heavy metal sliding sound. It’s unlike any other lightweight flywheel sound I’ve heard - you really need to look for it with headphones.
DCT v MT expectations.
One of the reasons why is the DCT has no throwout bearing, a common source of rattling even in a stock E9X M3 manual transmission.You can make it out starting at 20sec, oil at high temp, no trickery that hides chatter.
My bottom line
"It changes the driving experience and gets us ever closer to challenging GT3s.
It’s definitely something that should be on any DCT’s owners list."
The flywheel isn't exactly a DIY install: the exhaust, driveshaft and transmission are all coming off.
It's something you do usually while you're in there with other maintenance and upgrades to the transmission, driveshaft, etc.
This is your engine to starter alignment. Mess this up and the S65 won't crack once you have everything bolted back together.
"Take it from me, you don't want to have to do it twice (oups!)."
Pay careful attention to aligning the bolt hole with a different shape to the matching hole on the crank.
The TTV's shape is slightly less pronounced than the OEM flywheel shown below, but it's still visible if you pay attention.
The mission critical bolts.
You can't reuse the OEM bolts are they are encased in the flywheel. You need to get 9x new BMW flywheel bolts (11227520706).
The updated version comes with TTV Racing specific bolts they provide.
"I can't emphasize this enough: triple check the bolts you use. Use the wrong bolts can lead to catastrophic engine failure."
You dip them in engine oil while bolting them in, and you torque them criss-cross.