Thanks for your interest in my car. It started out as a 1998 528 with an auto trans. I am running the LS-1 and the GM 4L60E transmission (the donor car was a 1999 Firebird). I run the setup on a standard GM PCM which has a custom tune done to suit the turbo engine. It runs with a stock harness as it came out of the donor car, with the exception of the many electrical interconnections where power was needed to run the PCM etc. I did not retain either of the BMW computers as they were hooked almost entirely to the engine harness. In setting it up this way I lost traction control, but I did not want it anyway as I installed a limited slip differential to handle the power delivery. The BMW computers did not control anything else.

As I had to fabricate custom manifolds, I did not have any problems with the steering shaft, or the brake master cylinder. The BMW V-8 is a big engine, much bigger than the LS-1 and there is tons of space to do the swap. You may or may not have any interference with stock manifolds or shorty headers, but that would be pretty easy to modify even if you did have a problem. I intentionally chose a 528 for this project because I wanted rack and pinion steering which the 540 and M5 don't have, they use a steering box which just can't be as good, in my opinion.

The front sub-frame was only changed slightly to clear the oil pan, I did not even remove it from the car. Check out the attachment on this e-mail there are pictures of the change to the sub-frame.

The BMW shift cable assembly mated up to the 4L60E really well, all I had to do was modify the cable mount bracket where it hooks to the trans case and then I made a special smaller ball attachment on the 4L60E cable attachment. The throw on the shift linkage is exactly the same on the BMW trans as the GM unit. I guess this is not really that surprising as GM makes the BMW auto trans.

There were only a few modifications necessary for the new drive train to fit. First the front sub-frame had to modified to move the cross member forward in car about 2 inches to clear the front of the oil pan. I carefully cut the welds, shortened the cross member and then clamped in place and welded in back in. I was careful to duplicate the location of the BMW welds which were only on the top and bottom of the cross member. I also had to make some room in the tunnel on the passenger side to clear the transmission where the second gear servo sticks out (I think that is what it is). For this I I use a small bottle jack and simply dented the tunnel out by about one inch to clear the transmission.

With the sub-frame modified and the tunnel cleared the engine and trans fit in the car easily and only required the fabrication of three special parts. They are pictured here and consist of two stand-offs that mount to the LS1 block and reach down and mate up to the stock BMW motor mounts on the sub-frame in their stock location. The third part needed was a transmission cross brace. The stock BMW mounting holes on each side of the tunnel were retained and I just had to build up a piece that incorporated the original mounts location and then picked up the single bolt that sticks down from the GM transmission mount. The next step was the driveshaft and a swap out for the stock differential. The stock driveshaft was a two piece unit and I replaced it with a one piece 3 inch diameter drive shaft. The drive shaft incorporated 1320 grade u-joints that are more than capable of handling the torque that this beast delivers.