Swapping the N20B20A to N55B30

[X1E84Driver]

Hello guys,

I’m from Germany so please bear with my bad English skills.

My dad will pass me his X1 S20i facelift on and I’m excited about that car. It has the Automatik transmission (8speed) and it drives like a charm. Now after looking around in this forum I saw that manny people have an X1 35i. 6cyl with 306hp? In Germany we don’t have any X1 with that engine. Now if I informed myself properly that engine is the N55B30. I’m planning to put that engine in my X1 but wanted to make sure if it’s the right one before K buy it and swap it. Do i have to take care of other things like bigger fuel pump or bigger brakes. Upgrade the transmission or keeping it stock.

I’m happy about all the advices and comments (also about the negative ones)

Thank you in advance

[mcdanielvzw]

I doubt that would be worth it. You would also need the GE 6 speed transmission, as the ZF 8 was not used. That doesn't include all the other parts that I can't speak about personally (Transfer case/ECU/etc etc etc?).

[wheela]

People are upgrading their 6hp's to 8hp's now on their e-chassis BMW's. For information, Look into CANTCU, there are some threads about this over on spxxlstreet forum (replace the x's with o's - this forum censors out competing forums). So you may be able to stick with your current transmission vs. downgrading to 6hp (not sure if n20 8hp's got a different version of that zf transmission than f-chassis n55 cars with 8hp).

Your idea would be a cool swap, but no small task, and expensive, so research, research, and research some more to make sure you really want to go down this path before buying any parts. Once you're confident you know everything that will be involved, you can decide if you think it's worth it.

You probably already know, but there are WAY more tuning options for n55 than the n20, and way more power capability. Most performance items for e90 n55's work on this car.

[wheela]

I know a guy in the UK who's just finishing up swapping an n55 from his 135i into his e87. He's doing the n55 along with its original transmission from his 135i though.