Just a heads up for anyone with an e36 considering doing an M50 conversion: DDOOO IIITTTT!!! It was the best $330 + 6 hours of labor (2 spent BS'ing) that I've spent on the car so far. I did lose some torque, but the gains on the top half of the RPM range really made up for it. I have an S52 M roadster. From about 3,500 RPM's up to 7k, the power really comes alive now. I used to be a torque monster (just Dinan tune and fan delete) but after about 5,000 rpms, the car would fall flat. Now, on the other hand, I can really pull through the gears and drive it like it should be driven. Why didn't BMW do this in the first place?


Some observations:

1) Take your time with this one. There's a lot of hoses and it gets confusing. If you want to do it, PM me first and I can give you a hand for the price of a few beers. I think having experience on this job will make it go drastically faster. Instead of 6 hours, I bet I can do it in 2 now if I rush or 3 if I do it nice and slow.
2) I have a slight stutter as I accelerate. It started off with two separate stutters: one at 3k and one at 6k. As the ECU has been learning, however, I'm now down to one stutter at 5,500 and that seems to be going away. I expect the power to be smooth after about 500 or so miles.
3) The car is actually more drivable now. A little less torque and a little more high end power can really make a difference. Now I don't feel like I'm going to run into the guy in front of me in town and on the highway I can zip right around any slow-moving left-lane bandits without downshifting.
4) It's slightly more loud. I especially notice this when the engine is under light load at 2,500 rpms. The drone at that rpm is far more significant than before but most other times it's the same as before the swap.


All in all, I hope to dyno soon. When I do, I'll post up the numbers for you guys to drool over.