Nismo coppermix twinplate clutch

[The Skyline Guy r34]

Does anybody know the weight of the flywheel for the Nismo twinplate coppermix clutch kit for bnr34 over the standard flywheel? Is it a dualmass flywheel like oem or single mass?

[joshuaho96]

4 hours ago, The Skyline Guy r34 said:

Does anybody know the weight of the flywheel for the Nismo twinplate coppermix clutch kit for bnr34 over the standard flywheel? Is it a dualmass flywheel like oem or single mass?

It is not a dual mass flywheel, so you will get some gear noise on a BNR34 unless you deviate from the OEM fluid spec and run a thick gear oil like what Nismo recommended for a while. Unfortunately I have never weighed the flywheel by itself prior to installation but it is not that light. It's probably an 8-9 kg flywheel. OEM BNR34 dual mass flywheel is like 14 kg which is kind of hilariously heavy. 

[The Skyline Guy r34]

On 06/03/2025 at 1:17 AM, joshuaho96 said:

It is not a dual mass flywheel, so you will get some gear noise on a BNR34 unless you deviate from the OEM fluid spec and run a thick gear oil like what Nismo recommended for a while. Unfortunately I have never weighed the flywheel by itself prior to installation but it is not that light. It's probably an 8-9 kg flywheel. OEM BNR34 dual mass flywheel is like 14 kg which is kind of hilariously heavy. 

Are there any other lighter flywheels that can be used with nismo coppermix twinplate system?

Id like to gave the revs pick up faster than oem

[joshuaho96]

15 minutes ago, The Skyline Guy r34 said:

Are there any other lighter flywheels that can be used with nismo coppermix twinplate system?

Id like to gave the revs pick up faster than oem

No, with a twin plate clutch flywheels and clutch pressure plate/friction disks go together. Only clutch where that isn't the case is the Uniclutch but they currently don't make a pull version for the Getrag R34, just some other cars. Personally the flywheel is as light as I'd want it to be. It already drops revs faster than I want to shift normally and I blip the throttle again to rev match on upshifts.

[MBS206]

1 hour ago, joshuaho96 said:

No, with a twin plate clutch flywheels and clutch pressure plate/friction disks go together. Only clutch where that isn't the case is the Uniclutch but they currently don't make a pull version for the Getrag R34, just some other cars. Personally the flywheel is as light as I'd want it to be. It already drops revs faster than I want to shift normally and I blip the throttle again to rev match on upshifts.

Is there a diameter difference in the stock to Nismo?

If so, the weight alone won't be indicative when comparing flywheels of the same diameter, since the radius of the flywheel acts on the moment of inertia with a square factor, where as mass is linear.

Roughly going from a 4.5kg flywheel with radius 20cm, to a 9kg flywheel with radius 14cm would see them act the same. This calc is just here to act as a brief numbers comparison and reflects no actual RB flywheel diameters etc. it also assumes even weight distribution (thickness) throughout.

[joshuaho96]

11 hours ago, MBS206 said:

Is there a diameter difference in the stock to Nismo?

If so, the weight alone won't be indicative when comparing flywheels of the same diameter, since the radius of the flywheel acts on the moment of inertia with a square factor, where as mass is linear.

Roughly going from a 4.5kg flywheel with radius 20cm, to a 9kg flywheel with radius 14cm would see them act the same. This calc is just here to act as a brief numbers comparison and reflects no actual RB flywheel diameters etc. it also assumes even weight distribution (thickness) throughout.

From the pictures I have when doing the job the flywheel is the same diameter, I don't think they're playing weird tricks like putting weights at the outer diameter to increase flywheel inertia or anything like that. The OEM flywheel is definitely heavier, but it's not a huge difference. Quoted weight savings of the clutch is 2 kg so I can't imagine the flywheel being lighter than ~7 kg. Kind of regret not weighing it before the clutch went into the car but as far as driveability goes I have no complaints.