[T9T8]

I know there are some threads on this topic already but none of them give definitive answers. I have a 2010 LCI E91 328XI Wagon. I'm attempting to swap in a 335XI drivetrain (N54, ZF transmission, diffs, etc.). The parts that I'm fairly certain I need are as follows:

-Engine + Engine wiring harness
-Transmission
-Front+Rear Differentials
-Driveshaft
-Rear Output Shafts
-Exhaust
-Rear Bumper
-CAS+DME+Key

Things I'm not sure about needing are:

-Rear trunk floor
-Subframes
-Suspension components
-Any other control units or wiring harnesses

Few things I've read also include that extra wiring is required to swap from GM trans to the ZF trans, but I don't know what wires. Also the few threads seem to make it sound like everything is just "plug n play", curious to know if this is truly the case or if some VIN issues or other coding issues may occur. I also don't know if there are any difference between the front and rear differentials between the E90 and E92 335XI models.

Would love to hear some input, especially if anyone has tackled this project before.

[neilvan]

IF you are using the oem 335i Exhaust then youll need the 335 rear trunk floor (to fit the mufflers) which will have to come out of europe. Also it might be easier to grab a M-sport E91 rep bumper and just an E90 335 diffuser than source a standard 335 rear bumper out of europe

Suspension and subframes would be the same.

Im not sure about transmission/wiring but in this case doing a manual may actually be easier with the electronics.

Do you have a parts car? If you do, look at swapping the brakes over too and maybe springs(different weights for the right ride height)

[T9T8]

Originally Posted by neilvan

IF you are using the oem 335i Exhaust then youll need the 335 rear trunk floor (to fit the mufflers) which will have to come out of europe. Also it might be easier to grab a M-sport E91 rep bumper and just an E90 335 diffuser than source a standard 335 rear bumper out of europe

Suspension and subframes would be the same.

Im not sure about transmission/wiring but in this case doing a manual may actually be easier with the electronics.

Do you have a parts car? If you do, look at swapping the brakes over too and maybe springs(different weights for the right ride height)

So US E90 trunk floor cant be swapped over, it needs to be a euro E91? I've read that doing a standard trans swap is actually a lot more difficult and my dad (who I'm building this for) wants it auto. I do have parts car, its an E92 335xi, might do brakes, I already have coilovers installed so no need for suspension I guess.

[neilvan]

Good point on the trunk floor. Might was to go thru the part diagrams and see if the part # is the same. E91s only had the 335 in europe so thats why parts might be harder in the back.

Manual swap would be more parts and mechanical work but less coding/harness and electrical nonsense but I get its not for you.

Brakes would be a direct swap so may as well. Also Exhaust length might be slightly different as its a coupe.

[Thorin]

Brakes are a direct swap but you have to code the car for the change.