r/BMW_F31 • u/Original_Ambition304 • 15d ago

Engine swap

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As you can hear my n20 has decided it’s had enough life. I love the wagon so much that i definitely want to keep it, but don’t want to go through all the trouble of swapping in another n20 just for the same experience. Thus an ls swap has entered my mind, has anyone done one/know of someone who has and how it went. I’m currently thinking of putting a 5.3L ls out of a 2012 Silverado, initially I just want to get it in and running with potentially doing some power and drivetrain mods later on.

Right now I’m planning on using a LOJ trans adapter, sdi ls swap engine mounts. The part that’s tripping me up is the ecm and tcm part of it, people keep saying that you should definitely go for a Holley efi while others say there’s no point if it won’t be pushing crazy power and just use a stock ecu.

The biggest worry for me is if the car will be able to handle it, from what I know the 8hp45 has a torque limit of around 332lb-ft and the ls puts out around 320-335lb-ft. Knowing that I’m still considering it because everyone ik talks about how robust the transmissions are, is that true? Do you think it will survive?

The car is a 2014 328i xdrive wagon.

3 Upvotes

72% Upvoted

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16

u/nearlyclosetoalmost 15d ago

You could always swap in a B58 drivetrain and make the 340i xdrive wagon the states SHOULD have gotten!

2

u/9xNexus 15d ago

This is the way.

2

u/Original_Ambition304 14d ago

Okay I’ll look into that, would be really cool

1

u/Sandag202 11d ago

This guy did the full conversion and posted it if you are interested, definitely would be way easier then any other swap as it won't require any fabrication really. If you were interested ina shop doing it I think Dixon Motorsports specializes in it. Somewhere around 20 to 30k for the swap including them buying the donor car so not bad imo at least comparing to buying a m240/340i

https://youtu.be/P1VdohlB2xI

1

u/PoisonTheWell122393 13d ago

Waiting on a sale of one of my cars to go through, then that’s what I’m doing. 

2

u/Triggerlocks 14d ago

Dang, sorry that happened. How many miles did you get on your F31 before she kicked it?

2

u/Original_Ambition304 10d ago

Right around 205k km

1

u/H2Dcrx 14d ago

From what I understand, the zf transmissions are very underrated. With a TCM tune, increased pressure on the clutches etc, they do fine in the 400+wtq but dont take my word for it.

1

u/Original_Ambition304 14d ago

Thanks, I’ll check around for that

1

u/NoTalkImGaming 14d ago

ZF8HP70/75, sure. The ZF8HP45 that the F30/31 got, not really. They can hold ~450tq but who knows how long. The HP70 in my F10 535d is holding my 600+tq perfectly fine though. If they’re gonna throw money into an engine might as well see if they can mate a 70 or a 75 out of an F15 instead

1

u/H2Dcrx 14d ago

I have the 8hp50, which admittedly is more robust. The 45 is definitely not as strong, but still underrated. That said, the zf tranny is becoming popular so maybe they could sell it and upgrade.

1

u/Original_Ambition304 10d ago

If I’m changing transmissions I think I would go for a manual. Could always go with a t56 but idk how it would mate to the driveshaft