LS1+GS7 DCT into 318i

[midfat]

This is not a swap thread that will resolve itself quickly as I only have a few select weekends each year to work on the vehicle, but I am going to try to make the most of the moments I can. Picked up a very straight '85 318i Auto a few years back. The plan was to put an M20 2.7L stroker in it, along with a manual trans. I was fortunate enough to have access to a heavy surplus of race parts from a guy who moved on from E30 Chump Car racing. Got so far as to dropping in the new engine and trans, but then asked myself the question that one should never ask oneself: "Do all roads in fact lead to LS?" Needless to say, that set into play a series of costly events, along with thousands of hours of web sleuthing and YouTube video watching. Next thing I knew, I had sourced a cherry, low miles, LS1 from a '99 Corvette and a super clean GS7 dual-clutch short ratio 7-speed from a 2013 S65 M3. I'll try me best to keep this up to date, but feel free to ask questions if you have any. I have a plan, but I also know there will be much discovery along the way. You can also follow along via my insta @time_to_wrench. Let the fun continue!

[Panici]

Interesting, can't say I've ever seen that particular combo.

Will you need an aftermarket transmission controller to get the DCT working properly?

[midfat]

I've settled on the MaxxECU RACE controller because it supports both the Chevy LS and the BMW DCT in the same unit. I looked at the HTG GCU, but that requires rewiring the control board in the trans. MaxxECU on the other hand has cracked the BMW software encryption, so the transmission is literally plug and play (tuning aside). Having the same ECU control both the engine as well as the trans gives me some confidence that it won'y forever be chasing compatibility and communication issues. The more I explored MaxxEDC for this application, the more it seemed like the obvious choice.

[moatilliatta]

Looks like a driveline and suspension blender. You doing the wiring?

What else is next?

[midfat]

I can do the wiring, but MaxxECU has a fully terminated LS harness along with a factory BMW trans plug. I've weighed the pros and cons of doing it myself, but in the end I think I'm just going to bite the bullet and buy it turnkey. One less thing to tackle.

Next big push is definitely transmission tunnel. As my brother put it, this is "a huge donkey d**k" of a transmission. Length isn't the issue, it's height. I'll probably need to raise the tunnel an inch or so upward. Also, I wanted to keep the engine as far back as possible, and with the 30mm Domi-works trans adaptor plate, I need to create some additional clearance along the firewall. Interior needs to be completely removed to tackle the metal work. I'm trying my best to preserve the interior, but the heater-box is going to give me some challenges. I'll know more once i get the tunnel opened.

Other issue to deal with when I'm doing metal work is the battery tray. At some point, the battery boiled over and poured down behind the heat shield. The inside of the passenger foot well has issues, but it's the only crust on the chassis. It lived its entire life in SoCal.

[Panici]

I've settled on the MaxxECU RACE controller because it supports both the Chevy LS and the BMW DCT in the same unit.

Neat! I'm interested to see how the tuning goes with the MaxxECU, please don't spare us the details when you get to that point!

[midfat]

I've been remiss in giving any updates. Still working on fine tuning the fitment between the engine, trans and flywheel via the DomiWorks adaptor. First, DomiWorks makes some gorgeous stuff. Their kit calls for a flex plate with a ring gear for the starter, but I like the idea of running a true flywheel, so I shaved down the factory LS1 Corvette flywheel to clear the adaptor profile. That meant I also needed to trim the face of the crank hub adaptor because the flywheel is substantially thinker than the requisite flex plate. Seem to have resolved all of fit issues on the trans to motor, so moved on to cutting out the trans tunnel to get enough clearance for this beast. That's where I stand as of now.

[Panici]

That's a great picture!
Trans sitting in it's final position there, or is there still more to massage?

[midfat]

That's a great picture!
Trans sitting in it's final position there, or is there still more to massage?

Definitely needs some further massaging. I think I can get it another inch or two back, but that'll require some more side clearance. I need enough for the trans cooler lines. Once I get it placed, I'll box in a new trans tunnel. My hope it to be able to keep the heater-box. We shall see...