jmeenach wrote I would assume the DCT swap is relatively P&P. Sorry if I missed this earlier, but is there a reason you would prefer 8HP over DCT?
Scrippy wrote Has anyone reached out to Mike @ BPM regarding this swap? I’d bet Mike could bang this out for ya if he was contracted to do so. I’d even bet he’s already thought of doing so.
Yeah, the DCT swap is relatively P&P when you're doing it in a BMW chassis and powertrain combination that already has the appropriate DCT electronics and CAN integration. Once everything is physically plugged in, it's mainly coding/configuration.
It's a different story when you're putting a DCT into a BMW that was originally designed around the ZF8. The newer B58 cars are a good example. They came with the ZF8, and people have successfully done DCT swaps into them, but you're not necessarily getting the same factory integration. Depending on the chassis, you can end up needing an aftermarket TCU/CAN solution to make the DCT work properly.
Obviously it's an even bigger integration job when you put the BMW DCT behind a completely different engine or into a different platform, 2JZ, RB26, K24, LS3/6/7, etc.
The reason I'd prefer the 8HP isn't really because the DCT is inherently difficult to swap. It's because I honestly don't like the DCT that much lol.
The DCT is garbage IMO. It's great once you get on it, but it's really not a good transmission for normal street driving. And that's coming from me, someone who actually has a DCT and tracks a "stock" DCT.
Low-speed stuttering/jerkiness, weird gear logic, trash kickdown behavior, occasional shift delays, occasional random upshifts, and a lot of clutch management/slip at low speeds. Once you're driving hard, it's a completely different story and it works very well.
The other reason I prefer the 8HP is integration. You can absolutely control a DCT with a standalone and do all the same things, torque reduction, throttle blips, ignition/fuel cuts, etc. MaxxECU even has the BMW DCT CAN control built in along with CAN simulation.
The problem is that the BMW DCT relies heavily on the torque information and CAN data it's receiving from the engine and chassis, along with a bunch of different shift maps. So once you're outside of the exact OEM environment BMW designed it for, you have to start recreating a lot of that integration.
The 8HP is just much easier to integrate into different engines and platforms. There are a ton of aftermarket controllers and CAN solutions for it, and it's been used behind so many different engines that adapting it to a custom powertrain is much more of a solved problem. Its control strategy is also much less tied to reproducing BMW's specific DCT torque messaging and multiple shift-map strategy.
That's really the main reason I'd choose the 8HP. It's easier to integrate, especially when you're doing a custom powertrain, and I also prefer how it drives on the street.
The DCT is fucking awesome when you're beating on it. It's the part where you're crawling through traffic at 15 mph that makes me want to throw it in the trash lol.
Sorry for the off-tangent response lol, I went down this rabbit hole as I am still considering LS7 / DCT swapping my M3 lmao.
