e30 sport gearboxes

Post Mon Sep 25, 2006 3:01 pm

Hey Guys,

Anyone know if there are any differences between the gearboxes on an E30 325i and the mtec gearbox in the sport?

Post Mon Sep 25, 2006 3:44 pm

Gearbox in sport is close ratio.

Post Mon Sep 25, 2006 4:37 pm

Thats what I thought but checking the Bentley service manual it only lists one gearbox for the 6cylinder 325i and thats the getrag 260. is there some special ratio thing going on inside the 260 GB that makes it a sport?

Post Mon Sep 25, 2006 5:29 pm

These are the ratios i have for a sport(Mtech2).........TOP-0.81..........4-1.00........3-1.36........2-2.03..........1-3.35..........R-3.18 These are from a mag when the sport was tested as a new car. Any good to ya?

Post Mon Sep 25, 2006 6:23 pm

325: 3.35 2.03 1.36 1.00 0.81
320: 3.72 2.02 1.32 1.00 0.81

I found the previous figures for the 320 box in a previous post now adding the figured you just gave me

325 SE: 0.81 1.00 1.36 2.03 3.35

The 325 SE box is exactly the same as a 325 box I think. Anyone got exact ratios for the standard 325 box?

Post Mon Sep 25, 2006 9:49 pm

I think some 325se 's had a close ratio box fitted as an option? I can find 2 seperate articles (for a 1985 standard 325i) at 3.83/2.20/1.40/1.00/0.81

Post Mon Sep 25, 2006 10:10 pm

The 325i Sport box is a close ratio box, but its only 1st, 2nd and 3rd gears that are different. 4th and 5th are the same ratio as the non-Sport boxes.

Non-sport box -
1st 3.83
2nd 2.20
3rd 1.40
4th 1
5th 0.81

Sport box -
1st 3.35
2nd 2.03
3rd 1.36
4th 1
5th 0.81

Post Tue Sep 26, 2006 3:00 am

cool thanks guys! Also when you couple the sport box to a lower diff ie a 3.61 will the accelleration be slower than a standard 325i box with a 4.10 diff? If so how do I do the calcuulation? I would like to do an excell spreadsheet of speed to gear ratio in each gear with each respective box and diff. Perhaps it may be of use to some of the guys in here?