[BoostNinja]

Its the giving season right? I encourage everyone to share information instead of keeping good info secret, this helps progress the platform. I could of very well kept this to myself and gone faster and no one would of been the wiser. Happy Holidays!

The Idea:

I have been working on David Rooney's 135i DCT swap for awhile now. I am very familiar with the look of and weight of the n54 DCT flywheel. While reading about a clutch upgrade on a f80/82 I noticed a picture of the flywheel in the m3/m4 and it looked much different and much lighter. I was curious and used realoem to inspect weights of the two. The difference was huge. The m4 part rang in at 8.1kg and the stock 335is unit was a whopping 12.92kg! I verified they both used the same bolts, same bolt pattern, thread pitch, and same clutch pack. On paper everything looked great. Located a used m4 dct flywheel from a junk yard and the project was on.

The Swap:

When the m4 unit arrived I could immediately tell it was a much lighter unit. I verified the splines on the clutch pack were the same and test fitted it onto the crank of a n54 I happened to have in the garage. Everything looked as expected.

I pulled the trans out of my 335is and removed the DCT flywheel. The side by side shot says it all. The 335is flywheel is a typical bmw dual mass flywheel and the m4 unit while still listed as a dual mass did not have any noticeable play in it or even look like it was dual mass. It could be dampened internally but I could not be certain.
As you can see in the photos the weight difference huge 10.5lbs between the two. The flywheel bolted right up. I used new flywheel bolts and torqued to the m4 specifications. The two cars share the same bolts.

The Results:

I took before and after free revving videos at roughly the same operating temp and the difference is noticeable.

https://youtu.be/2gjf0byD6zQ

The car felt quicker after the upgrade, no more or less than expected. Worth the 300 dollars to me. I am hoping it will help my launches at the drag strip because I've been leaving too hard with the stock flywheel and 5k launch. I am also hoping this is easier on the rest of my driveline.

[Julian2485]

Originally Posted by BoostNinja

Its the giving season right? I encourage everyone to share information instead of keeping good info secret, this helps progress the platform. I could of very well kept this to myself and gone faster and no one would of been the wiser. Happy Holidays!

The Idea:

I have been working on David Rooney's 135i DCT swap for awhile now. I am very familiar with the look of and weight of the n54 DCT flywheel. While reading about a clutch upgrade on a f80/82 I noticed a picture of the flywheel in the m3/m4 and it looked much different and much lighter. I was curious and used realoem to inspect weights of the two. The difference was huge. The m4 part rang in at 8.1kg and the stock 335is unit was a whopping 12.92kg! I verified they both used the same bolts, same bolt pattern, thread pitch, and same clutch pack. On paper everything looked great. Located a used m4 dct flywheel from a junk yard and the project was on.

The Swap:

When the m4 unit arrived I could immediately tell it was a much lighter unit. I verified the splines on the clutch pack were the same and test fitted it onto the crank of a n54 I happened to have in the garage. Everything looked as expected.

I pulled the trans out of my 335is and removed the DCT flywheel. The side by side shot says it all. The 335is flywheel is a typical bmw dual mass flywheel and the m4 unit while still listed as a dual mass did not have any noticeable play in it or even look like it was dual mass. It could be dampened internally but I could not be certain.
As you can see in the photos the weight difference huge 10.5lbs between the two. The flywheel bolted right up. I used new flywheel bolts and torqued to the m4 specifications. The two cars share the same bolts.

The Results:

I took before and after free revving videos at roughly the same operating temp and the difference is noticeable.

https://youtu.be/2gjf0byD6zQ

The car felt quicker after the upgrade, no more or less than expected. Worth the 300 dollars to me. I am hoping it will help my launches at the drag strip because I've been leaving too hard with the stock flywheel and 5k launch. I am also hoping this is easier on the rest of my driveline.

Great find bro I wonder if the m3/m4 clutch will fit the n54. I remember seeing a thread where a m4 with pure turbos had 700 hp running on stock clutch.

[FoShizzle]

This Is very cool. Well done. You make this sound like a quick swap. Is this feasible for a regular diy guy to do in the garage on jack stands or ramps?

[BoostNinja]

Originally Posted by Julian2485

Great find bro I wonder if the m3/m4 clutch will fit the n54. I remember seeing a thread where a m4 with pure turbos had 700 hp running on stock clutch.

The m3/4 dual clutch trans clutch pack is the same as the clutch in the 335is as well as any other dct trans. I know there are several cars out there pushing 700+ with upgraded clutches from Dodson and SSP.

[Julian2485]

Originally Posted by BoostNinja

The m3/4 dual clutch trans clutch pack is the same as the clutch in the 335is as well as any other dct trans. I know there are several cars out there pushing 700+ with upgraded clutches from Dodson and SSP.

Wish there was a clutch upgrade without any clutch chatter for the 6spd

[BoostNinja]

Originally Posted by FoShizzle

This Is very cool. Well done. You make this sound like a quick swap. Is this feasible for a regular diy guy to do in the garage on jack stands or ramps?

I would advise against trying to do this without a lift and a tranny jack. I'm sure someone could do it but lots of swearing would be involved and they could injure themselves.

[feuer]

How this works when flywheels aren't same height?

[homemade_f81]

Originally Posted by feuer

How this works when flywheels aren't same height?

They're the same height where it matters. If you look at the first picture, the center section with the splines is the same exact height - that's the place where it matters. The big outside ring on the N54 flywheel is there to help smooth out engagement and help with harmonics - there is nothing that touches it.

[Julian2485]

Originally Posted by swedishpowah

They're the same height where it matters. If you look at the first picture, the center section with the splines is the same exact height - that's the place where it matters. The big outside ring on the N54 flywheel is there to help smooth out engagement and help with harmonics - there is nothing that touches it.

I think I have the 8 bolt flywheel I have a 2009 e90 335xi

[marcvtec]

Originally Posted by Julian2485

Wish there was a clutch upgrade without any clutch chatter for the 6spd

+1

[Julian2485]

Originally Posted by marcvtec

+1

Would be nice if the m4 6 spd clutch could fit our cars

[Jeff@TopGearSolutions]

Any noticeable difference in harmonics, NVH, vibration, noise ETC?

[BoostNinja]

Originally Posted by feuer

How this works when flywheels aren't same height?

You should look at the construction of the dual clutch transmission, clutch, and flywheel and you will have a better understanding.

Nothing like a traditional flywheel, clutch, and pressure plate.

[BoostNinja]

Originally Posted by Julian2485

I think I have the 8 bolt flywheel I have a 2009 e90 335xi

This is for a dual clutch transmission only. Shouldn't concern you with an xi. DCT is not available for awd cars.

[BoostNinja]

Originally Posted by Jeff@TopGearSolutions

Any noticeable difference in harmonics, NVH, vibration, noise ETC?

Sounded a little louder while standing under the car running on the lift but in the car sounded the same. My diff with sold mounts is much louder.

If you want a feel for what it sounds like ride in a m3/m4 with a DCT

[katsooba]

well guys, having started a list on another forum to help everyone have a lightweight flywheel on the DCT cars
i am seeing on realoem that the e92 dct N54 and the 135i N55 flywheels are the same.
so this options is viable to everyone with a N54 E92 DCT and E82\88 N55 DCT.

Stephen from MFactory said to have their price the same as the M/T trans flywheels - 500$

they already have a DCT flywheel sample going out to them and with 10 people pledged in they gonna make our DCT work great

quoted from him on the other forum -
" If we can get at least 10 people on board (i.e confirmed with a 50% deposit), we can make our SMFW's for the DCT (will be same price as our MT SMFW's). Lead time around 2-3 months."

[gips]

Originally Posted by katsooba

well guys, having started a list on another forum to help everyone have a lightweight flywheel on the DCT cars
i am seeing on realoem that the e92 dct N54 and the 135i N55 flywheels are the same.
so this options is viable to everyone with a N54 E92 DCT and E82\88 N55 DCT.

Stephen from MFactory said to have their price the same as the M/T trans flywheels - 500$

they already have a DCT flywheel sample going out to them and with 10 people pledged in they gonna make our DCT work great

quoted from him on the other forum -
" If we can get at least 10 people on board (i.e confirmed with a 50% deposit), we can make our SMFW's for the DCT (will be same price as our MT SMFW's). Lead time around 2-3 months."

In Russia, the single-mass machined aluminum flywheel 135, weight 4.8 kg = 10.58218718509 lb
https://www.drive2.ru/l/7106322/

[katsooba]

i dont think that single mass on the DCT would be nice as a daily driver

[BoostNinja]

Originally Posted by katsooba

i dont think that single mass on the DCT would be nice as a daily driver

i haven't heard any m3/m4 owners complain about it.

[MFactory]

Originally Posted by BoostNinja

i haven't heard any m3/m4 owners complain about it.

I think he was meaning the Aluminium SMFW versus Steel SMFW, as they don't absorb as much noise.

[Jeef]

Originally Posted by katsooba

well guys, having started a list on another forum to help everyone have a lightweight flywheel on the DCT cars
i am seeing on realoem that the e92 dct N54 and the 135i N55 flywheels are the same.
so this options is viable to everyone with a N54 E92 DCT and E82\88 N55 DCT.

Stephen from MFactory said to have their price the same as the M/T trans flywheels - 500$

they already have a DCT flywheel sample going out to them and with 10 people pledged in they gonna make our DCT work great

quoted from him on the other forum -
" If we can get at least 10 people on board (i.e confirmed with a 50% deposit), we can make our SMFW's for the DCT (will be same price as our MT SMFW's). Lead time around 2-3 months."

Can't find this anywhere. Can you pm me in the right direction? Thanks!

[Andym3100k]

Originally Posted by Jeef

Can't find this anywhere. Can you pm me in the right direction? Thanks!

Here u go...

http://www.n54tech.com/forums/showthread.php?t=44226