Turbo M20... what Diff. should one use?

[bimma360]

Is the stock 3.73 LSD good enough?

[TCD]

I have a 3.25 in the car now but am changing to a 2.93
Todd

[randomtask37]

depends on the power u are puttin out. more power = lower diff ratio

[bimma360]

Thanks for the response TCD. I'm going to start gathering the stuff for the turbo project this summer... i really want to get it done by the end of the summer... we'll see. I have been reading up on all the turbo guys. I am really interested in how your car dynos. Why the 2.93... does the 3.25 rev up to much for the amount of power you're goin to put out? Oh by the way... i think i'm goin to be buying a lot of parts from you... hahah.

[bimma360]

lets get a list goin of power range and proper diff..... i'll start:

stock 325i.... 169hp = 3.73

.... hahah.

[E30godz]

yea even with just 6 psi that i was running, first gear went awfully fast.

[bimma360]

yea even with just 6 psi that i was running, first gear went awfully fast.

how much power are you gettin out of 6 psi... i'm still tryin to decide how much power i should make my m20 handle.

[Stu]

4.11 if you don't have too much power and a decent redline (7000ish).


Maybe 4.27

[Rob]

stu, this is for a turbo car....

[CiLK WuRM]

Wrong way Stu!

[TCD]

Why the 2.93... does the 3.25 rev up to much for the amount of power you're goin to put out?

The car is OK with the 3.25 at it's current power level but it still spins 2nd gear rolling into the throttle so with the additional power this car is going to see, the 3.25 would be useless.

Plus I want 30mpg on our trip to Road America for One Lap.
Todd

[Stu]

3.91 would be hot too, 'specially a VC.

As I said, if it's not too much horsepower (250ish, 275), run a fairly short gear. You'd want a longer gear if it were in the '3 n a quarter' range.

[E30godz]

what tires are you running TCD?

i want to be able to spin the tires just by flooring it in 2nd 8(

[TCD]

195/65/14 snow tires. Greg is delivering some 15x7s this weekend that will get new 225/50 tires.
Todd

[diegom6]

Is my Turbo system fucked up or what?? lol, cuz I have 3.91 LSD (changed when it was N.A.) for my 3.73LSD and even with the turbo I do not spin the tires in second gear, I mean I don't have traction problems, just if I shift quikly in second gear and realese rapidly the cluth it will "chirp" or spinn a bit...but no more than that, anyways I will swapp again my old 3.73 LSD , in that way I have a good low response.

BTW: I'm using stock basketwaves 215/55 R14 Crappy Hankook tires...this weekend I'm changing for 16" :P