"This entry is part of a Special Series on my S65 lightweight flywheel experiments as a part of my Ultimate Response Blueprint.

I’ve always been weary of lightweight flywheels and was anxious to installing this considering the labor involved.

In this entry, I start her up and go for a drive.

Was it worth it? Tolerances vary, read and listen carefully! "
- Matt

How it sounds. 

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.

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.

I can describe the sound 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 first test drive. 

On my first test drive, I thought the clutches & flywheel were slipping off each as it was so much faster. 

The flywheel fixed a common complaint about the sluggish mid range of these engines: you feel catapulted from 3,000 into the 5,000 + zone. 

It drastically improved the DCT’s shift operations; everything happens quicker now with no added jerkiness. The throttle blips on downshifts are more aggressive than ever. 

I unwillingly hit the 8,600 limiter a few times, catching another gear much faster than it used to. Maybe tires were slipping too.

They weren’t.

Reduced moment of inertia is how this feels. 

The reduced moment of inertia is most impactful in the low to mid range as this is where it takes most energy to get the crankshaft rotating. The flywheel has less impact on the upper range response. 

Think of it as a Spinning Class, getting your bike's plate moving is a strenuous effort. Once it gets going, the mass nearly moves itself. 

This is an unedited, raw clip to show the true, sound and effects the TTV flywheel has on the S65 & DCT. 

Is this made for every S65 DCT owner?

I don't think so.

You will be giving up comfort in the process.

Was it worth it for me?

Entirely.

It transforms the drivetrain and gets us ever closer to challenging GT3s.

I like the sounds: it's mechanical - like a 911R, who famously came fitted with a lightweight flywheel. 

I've worked with TTV to offer this year long. You can order the flywheel for the DCT and MT here.