[VIERsr]

Originally Posted by heavyD^2

DCT's always employ a lighter flywheel and it's because the computer knows when the car is going to upshift and the 2nd input shaft is already in place for the next gear which is why shifts are lightning fast compared to what's possible with a manual or slush box. With a manual transmission manufactures have to be mindful that an ultra light flywheel will not make for a compliant street car. I remember my DSM days with Fidanza flywheel well but it took work to get a good launch with it and if you weren't on the ball during a commute for the street things could get jerky. Personally I felt the cons outweighed the pros for a daily driver as I saw only a mild improvement in engine response and willingness to rev.

You are right, a MT car with a light flywheel would be undriveable daily on streets. But if someone drive both DKG and MT M2 can feel the difference due to the different weight of the flywheel

[CSBM5]

Originally Posted by _RS4_

You are right, a MT car with a light flywheel would be undriveable daily on streets. But if someone drive both DKG and MT M2 can feel the difference due to the different weight of the flywheel

I assume it's the case similar to the E9x DCT where the DCT has more rotating mass internally with its dual clutches and shafts, etc, compared to a 6MT, so it's not a simple comparison.

[Poochie]

Originally Posted by _RS4_

You are right, a MT car with a light flywheel would be undriveable daily on streets. But if someone drive both DKG and MT M2 can feel the difference due to the different weight of the flywheel

For quick launches, if you're skilled, a lightweight flywheel will feel great..

But once you get up to speed, it's harder for a lighter flywheel to keep the engine spinning, especially when you let off the gas.

The weight of a manual flywheel is selected to create a certain amount inertia to keep going. Which is automatically generated in the DCT.

[chris719]

It's not the flywheel, it's in the DME / ECM as others have mentioned. It's on purpose, for reasons I can only surmise are emissions and efficiency related.

A lot of new cars have this, even the Corvette which is NA.

The first thing you notice in a new MT car is when you let off the throttle you don't get immediate hard engine braking, feels like you get a moment until the fuel cut actually happens or the throttle fully closes. That was not the case in my Z4M (S54 is also drive-by-wire / electronic throttle). The throttle was super responsive and revs dropped like a rock.

I wonder what it would be like if BMW had a non street legal DME firmware.

[warrenw]

Originally Posted by Proctor750

Have you taken out the little delay valve?

Removing your CDV doesn't eliminate rev hang, it just ensures that the point your clutch engages at is the same every single shift.

[OperationSunset]

Put the engine in Sport+ and you'll see 60% of the rev hang go away (on my '21 M2C). On top of that, drive the car a bit more aggressively and you'll forget you have rev hang...I realized I was granny-ing it for the first 10k miles and then unlocked a ton of fun when I stopped doing that.

I have to admit though that my ND Miata 6MT really ruined the feel for me. There is virtually 0 rev hang in that miata...it's just snap snap snap into the gears. I'll still take the m2c over it any day because the torque of the S55 is simply intoxicating.