who has what diff?

[1990m3]

Road America is a fast track. I would put in the 3.73 with the 5 speed.

Euro motor has another 600-1000 revs to work with than a US motor. Makes a big difference. I wouldn't use a 4.27 or a 4.45 with a 5 speed. The 5 speed with a 3.73/4.10 vs a 6 speed with a 4.27/4.45 is similar to the E30 M3 OD vs CR gear box. 2-6 on the 6 speed are closer spaced than 1-5 (5 speed and 6 speed has same first 5 gear ratios).

yes it is a fast track, I was upwards of 155mph in that car, easily. It walked away from my lowly 4-cylinder m3 about as fast as any other car out there.

He does have a race prepped motor using 7500RPM IIRC. Those gears on the 6 speed were very tight with that diff though. I rode in the car a month prior at Blackhawk Farms (short tehnical track) and it seemed like the gearing was more suited towards the short track.

[94is]

Road America is a fast track. I would put in the 3.73 with the 5 speed.

Euro motor has another 600-1000 revs to work with than a US motor. Makes a big difference. I wouldn't use a 4.27 or a 4.45 with a 5 speed. The 5 speed with a 3.73/4.10 vs a 6 speed with a 4.27/4.45 is similar to the E30 M3 OD vs CR gear box. 2-6 on the 6 speed are closer spaced than 1-5 (5 speed and 6 speed has same first 5 gear ratios).

You talk euro motors everywhere you go, don't you? :p

[etxxz]

3.25 s52 obdii with ZF 5spd. does 154mph (theoretically on 195/60/14). i think the gearing is kind of short for a DD, but this is a hybrid track car so i really don't mind doing 60mph at 3k, 80 at 3.6k....and now that i'm getting 16-17" rims, i'll have the gears just where i want them.

if i was getting more power, say euro motor, i would've gone with a 2.93

[gobuffs]

He does have a race prepped motor using 7500RPM IIRC.

7500 in a US motor is dangerous territory. Seems like people with Sunbelts tend to stay under 7k.

[gobuffs]

You talk euro motors everywhere you go, don't you? :p

Well I got one...so....and the question was asked about diffs and the motor makes a difference no? :-)

[94is]

Well I got one...so....and the question was asked about diffs and the motor makes a difference no? :-)

I haven't even ordered mine yet, and I think/talk about it all of the time. :-)

When I finish this e30 and get paid, Alex will get his check. :D

[DaN]

s50, zf 5 speed, Z3m 3.15 diff.
Muuuuch more usable than the 3.73 for daily driving.

[BeirBrennerE30]

3.91 here with s52 and e46m3 6speed..

love it... great acceleration and comfortable on the highway. No downside.

p.s. the euro 6speed is a waste of money. the e46m3 6speed(getrag s6s-420g) is the updatesdversion of the same transmission and can usually be found for half the price in the US. Its also the same transmission used in the 6-speed supra so it can take a BEATING

[PiercedE30]

3.91 here with s52 and e46m3 6speed..

love it... great acceleration and comfortable on the highway. No downside.

p.s. the euro 6speed is a waste of money. the e46m3 6speed(getrag s6s-420g) is the updatesdversion of the same transmission and can usually be found for half the price in the US. Its also the same transmission used in the 6-speed supra so it can take a BEATING

I would LOVE to have that same tranny. When I get some free cash I will be on the look out.

[gobuffs]

p.s. the euro 6speed is a waste of money. the e46m3 6speed(getrag s6s-420g) is the updatesdversion of the same transmission and can usually be found for half the price in the US. Its also the same transmission used in the 6-speed supra so it can take a BEATING

So you can find E46 M3 trannies for $1k-1250? Car Part shows them for about the same price as a Euro.

[bostonbmw]

3.91 here with s52 and e46m3 6speed..

love it... great acceleration and comfortable on the highway. No downside.

p.s. the euro 6speed is a waste of money. the e46m3 6speed(getrag s6s-420g) is the updatesdversion of the same transmission and can usually be found for half the price in the US. Its also the same transmission used in the 6-speed supra so it can take a BEATING

what did that run you ?

[Mike B.]

So you can find E46 M3 trannies for $1k-1250? Car Part shows them for about the same price as a Euro.

All the one's I've seen have been going for $2000 to $2500. That is one of the reasons why I stayed with the E36 M3 ZF ($450) for my euro swap. $2000 buys a lot of cool stuff! ;)

[BeirBrennerE30]

i got the trans for $1400 shipped like 3 years ago... from an '03 m3 that had 8k on the clock. At the time the euros were around $3000.

The so even if you had to pay 2k for the e46m3 6speed... thats only 1500 more than using the e36m3 5-speed. You get an extra gear and the ability to use a much lower rear end. I think you would be hard pressed to get the same acceleration benefit from an s52 for 1500. Cams are all i can think of that would come close

[Mike B.]

Choices, choices, choices... I've spent a ton on mine and there are still things that I would like to do differently.

I'd love to do a build with an unlimited budget one of these days. :)

[JPStrniste]

Choices, choices, choices... I've spent a ton on mine and there are still things that I would like to do differently.

I'd love to do a build with an unlimited budget one of these days. :)

...wouldn't we all