[HOW TO] e46m3 6-speed your e30

[ban1]

Can't wait to use this write up next year after deployment.

[e30love]

damn

[chuck90m3]

wrong bellhousing you need a 6SMT from a 6 cylinder car

[e30love]

how about the 420 out of the e34 will it work?

[chuck90m3]

I can it is around $450 with parts and you would need to cover shipping

[bmike666]

i have a spare smg tranny

It can be done, we did three this month for our project cars

wondering if you can get mine to work normal and how much? thanks

[chuck90m3]

It can be done, we did three this month for our project cars

[BMWtech@mac]

^^^ Thanks for the info. I always seem to come across the SMG's for sale at good prices so it was just a thought.

[chuck90m3]

They are not the same. I thought so as well but after buying one found out that the SMG transmissions come without the necessary parts to center the shifter in neutral and provide the shifter with the dedent for reverse. We have sourced out the parts to make them work but you need to drill and install a few springs and guides so the transmission will work properly. As for the gear ratios they are the same.

[BMWtech@mac]

Does anyone know for sure, if the e46 M3 SMG trans is the same as the regular 6 speed in a e46 M3. Would you need any other parts to make it work? Gear ratios the same? If you take off all the SMG stuff, can you use this trans in this swap? Also, is the 6th gear a considered a overdrive gear? The reason I ask is I'm already running a 3.73 rear gear and I would like to be able to drive on the highway at something less than 4500 rpms like I'm at now... the reason I don't drive my car on the highway, haha.

Christian

[GGray]

Nice

Thats perfect with a 3.25. You can hit 60mph in second gear. for a track being able to hit 124/125 is great most of the tracks I go to at the end of the straight your pulling 120ish. Not having to shift up a gear and back down two is perfect...

I just bought a 1990 325 with an S50 in it:up:

[e30polak]

Just adding a little info for those considering a 6-speed swap. Here's the speed/RPM calculations for an E46 M3 6MT (S6S 420G) with my tire size and differential. I can post other combinations if anyone needs, including substituting gear ratios for the ZF 6-speed. LMK.

I want to do this tranny with a 3.46, get into powerband a little quicker! :D

[BeirBrennerE30]

^^ I also would like to know?

im sure you could hook it up but i have no idea what your clutch pedal would feel like. Try it

[BMWtech@mac]

^^ I also would like to know?

[bmike666]

why use a e36 slave cylinder

i get asked pretty frequently how i fit the getrag s6s-420g transmission from the e46 m3 into my e30. So instead of answering the question a few times a week i thought i would just do a write up of the parts necessary and some tips and notes.

Parts:

E46 m3 getrag s6s-420g transmission
e46 m3 flywheel
e46 m3 clutch
e36 325i clutch slave cylinder(there may be a better option out there but i know this works, the pedal is kinda light for my taste)
custom trans x-member
automatic e36 m3 with e30 csb driveshaft
e46 m3 guibo
e36 engine to trans mounting hardware(e46 stuff is too long)
e46 m3 driveshaft to trans hardware (12mm bolts)
e36 m3evo shifter assembly(details below)
e30 late model rear shifter mount
shift knob with 6-speed shift pattern ;)

install highlights:

The e30 reverse light switch threads into the e46 trans no problem and functions

you need a lower rear end gear ratio. I run a 3.91 and its very streetable. For a daily driver the 3.73 would probably be perfect.

For the shifter you need the e36 m3evo 6-speed parts:

thats everything in the above pic except 12,13,14,15. You need 1-11! This will slide into the late modle e30 rear shifter support. For early e30s(pre '86) you need to convert to the later style mount.

For a drive shaft you need one of custom length made. ( or apparently you can use an e36 m3 automatic driveshaft with an e30 center support bearing swapped in ) bimmerworld made mine and make a very quality unit. They will send you a sheet to fill out with critical measurements like the one below.

for me the measurements were the following:
1. 21.5"
2. 54.375"
3. 1.375"
4. Stock e30 non-m length
5. E46 m3 flex disk
6. 12mm bolt hole
these may change depending on your particular set-up. Make sure you confirm these measurements on your car before you order. If it doesn't fit its your fault!!!


As for the custom x-member your on your own. You can use the stock e30 x-member and weld on extensions so that it reaches the front and rear sliders.

Thats it!

Technical notes:

Gear ratios:
1st 4.23
2nd 2.53
3rd 1.67
4th 1.23
5th 1
6th 0.83

the internals of this transmission are the same used in the 6-speed mkiv supra. So its basically indestructible.

This trans is the upgraded version of the e36 6-speed. The syncro problems of the e36 were fixed to solve the miss-shift problems and early wear.

will a e46 m3 slave work