[mcp]

Couldn’t find any information whatsoever concerning this exact swap, so I figured I’d make a thread and go over everything I’ve found so far.

Fitment issues: No clue how the transfer case will mount up, but could definitely be an issue. Given that the rear end is the same as RWD and the chassis is the same between xi and is models, I figure some kind of custom mount will be possible with little to no modification.

Hardware issues: AWD and RWD have different DSC/ABS modules. Conversion to RWD module is physically possible but not worth the effort, as hard brake lines are different for some reason. Also likely it would render the AWD permanently off. The swap hinges on if the ECU and TCU can work nicely with the AWD DSC module.

Upgradability issues: A complete M3/M3 GTS swap seems unlikely, as the one detailed thread I found has a M3 DSC/ABS module as part of the swap. However, it seems like it’s only needed for M Mode. Variable launch and Drivelogic should be fully attainable.

There doesn’t seem to be any way to prove or deny the ABS module compatibility without someone trying the swap i believe. If the module is “self sufficient” and doesn’t directly interact with the TCU and relies on wheel speed sensors, I definitely believe this is possible.

If I find the DCT + flywheel for cheap enough, I’ll definitely try the swap myself and update this thread. If anybody has any experience with this or any info I missed, definitely drop it below.

[E92_William]

You can put the dct in a rwd 335, however there's no way you can fit the transfer case in it. The awd transmission has a splined output shaft which goes into the input of the transfer case and then the transfer case output shaft is the one with the guibo itself that will connect to the driveshaft. The dct transmission doesn't have any way to attach the transfer case at the back of it.

If you just want to get rid of the awd system I think some guy here in the NA forum put a rwd transmission in an awd car with an adapter mount