Questions for the m20 guys

[Nick]

What rear end is everyone running? Will a chip make it just too crazy? Planning on running IE coilovers in the front, big brakes and IE stage 2 springs in the rear with bilstein sports. Have a non LSD 3.90 right now, planning on using that until it gives.

[Pierre]

The E30 had a 3.73 in a 5-speed, anda 4.11 in the automatics.

In a 2002, I would recommend a 3.64. A 3.90 would simply too short especially that the 2002 has shorter tires and will givr you a shorter final drive.

[ERIC02]

Hello, just chipping will not give crazy power gains maybe 10to 15 and i think as long as youre not "shocking" the the rearend alot. ie burnouts and driving the car like you stole it everyday you should be fine. The M20 i just bought for my conversion is out of a 320i that i got from a friend and it has a chip and a little head work and 325i intake and airflow meter and it has (and this is tested from the german TÜV and put in the registration) 150 hp and 215N-m torqe (or around 150ft lbs ) alot of people will probably say why not M10 with 150hp but i think here in germany i could do an s14 swap cheaper than a m10 with 150hp and at this stage i am doubleing hp (i have a 1502 @ 75hp) cost till now 50 euros. sorry for rambling on but ive drank to much coffee. Eric

[Bobby_Digital]

I've got a 3.91 lsd diff out of a 320i with no problems. There was a guy selling a few of them from somewhere in the Inland Empire and I picked it up for $200. Bonus, he drove it out to me! As Pierre said, it is pretty short and likes to spin the tires in first. Isn't too short and buzzy for freeway speeds, though, with the e30 5-speed. I've heard of these breaking with lots of burnouts and hard driving. Talk to Ed at Groma about fabbing up an e30 rear end and subframe if you plan on going that route.

I haven't chipped the ecu yet, but don't think the gains are crazy if you do.

Rob

[-=Charley]

I will agree with Pierre on the 3.64, I have a 3.91 in mine and it renders 1st gear useless and runs 5th out around 100mph. the 3.90 is useable though, so build up a nice 3.64LS on the side and swap it in later. for the chip, I'd say, get it runnin 1st and then decide if u wanna chip it. at that point, you may feel the $'d be better spent upgrading your cooling system, tires, etc. ask me how I know.

[Nick]

thanks for all the info, sounds like if I don't drive like a maniac, I can buy myself some time. The 3.64 lsd sounds like a great middle ground. The car is currently at Groma Fab getting the transplant done, keeping it simple for now. The e30 rear diff does sound pretty nice though!