john i heard that they have

a 411 and 440 gears for a e46 m3. i am curious my self about people who have the larger number rear gear in their car.i know
one guy who as a 391 gear in his e36 m3 and he loves it. but
he does't spend alot of time in the fanatics. he is in bimmer
forums.
bobm3 :thumbup: :thumbup:

 

3.91 is a great choice.

Much lower than that and 1st gear really becomes worthless for anything other than generating tire smoke.

You should not experience any additional noise or vibration - it's simply a different ratio, the basic gearset should work like your 3.64.

The big question is are you going to transplant the hydraulic Motorsport LSD unit? Unless you find one used and put it into your new 3.91, you are facing additional labor charges to disassemble your 3.64. Of course, you have to consider if you are going to get an additional housing so you can have the new diff built complete and then swap diffs, which allows you to keep your 3.64 intact if you decide to swap back.

Furthermore, if you do not get another Motorsport LSD, you could have the 3.91 built with a conventional LSD (which means it will work the same even when cold, unlike the hydraulic Motorsport unit) or the infinitely variable Quaife Automatic Torque Biasing diff, which works the same as the Motorsport LSD but is not subject to temp differences or power loss.

For exploring hard dollar numbers on any of these options, I suggest you contact Brett at KMS - 440-338-1650 or brett@koalamotorsport.com

- Rob

 

i sat in a friends m3 this weekend which had the 3.91 diff on and let me tell you that car moved. of course he has other mods but the car was insanely fast. i would have to say that the butt dyno told me it was like the sports button x 10.

that being said, i am sold and want to do the same mod but need to find out some more information as well. john, if you find out info and prices please pass it my way. thanks!

 

This is also a conversion I am interested in....

: popcorn:

AdamR

 

I have been researching the 3.91 M3 also. Dinan makes one
technik, turner motorsports are other sources. m3forum has a few threads. I will definitely do this at some point though by the time I can my car will be a real antique.

 

if you are going to do it then get the 411 one

to see a real defference in geting off the line. and if you put in a shark injecter top end will be 175mph because of the softwear..... i heard their is not such a big difference from 364 to 391 rear... that is why i say get a 411 rear gears.....
bobm3 :thumbup: :thumbup:

I have been researching the 3.91 M3 also. Dinan makes one
technik, turner motorsports are other sources. m3forum has a few threads. I will definitely do this at some point though by the time I can my car will be a real antique.