beef up step tranny?

[Luke WL.]

Ive heard that the step tranny can only hold about 300hp and 310lb/ft torque? if this is true (if i were to get a turbo) is there a way to beef up the tranny to hold some where arround 370 hp?

[gmhl10]

Ive heard that the step tranny can only hold about 300hp and 310lb/ft torque? if this is true (if i were to get a turbo) is there a way to beef up the tranny to hold some where arround 370 hp?
Me wants to know too!!!
For "educational" purposes. ;)

[325i-Vizon]

i vant to know as well :craig:

[teamdfl]

You can't afford to go that fast.


Actually, I have heard of guys getting performance rebuilds on factory ZF slushboxes with improved bands, clutches, sprags, and whatever the hell else keeps an automatic from grenading. The problem is cost. A ZF reman runs $2k + and a performance slushbox will run at least double that if you can find anyone who will stand behind their work. Don't forget about a larger transmission cooler too. If you want a higher stall speed, plan on spending $1k + for a custom torque converter.


Ed

[Mr Paddle.Shift]

You can't afford to go that fast.
Ed

Bingo.

I have a Step and somehow I am not bothered by this. I see it as a way to curb my mod-spending habit. As of now, the car is more than what I need for track events. In fact, the first thing I did after installing ASA was to track the car, not to dyno. :loco:

[crazy1323]

Bump

[xS3x]

i have a steptronic transmission for sale if anyone needs it for a rebuild :thumbup:

[Mr Paddle.Shift]

You need a ZF 5HP24. This is what Alpina uses in their B10 V8s and V8 Roadster.

[sfzBimmer2]

You need a ZF 5HP24. This is what Alpina uses in their B10 V8s and V8 Roadster.
Would this be an easier swap than a manual transmission swap, in terms of software especially?

[xS3x]

I doubt the tranny will bolt up though? :dunno:

[Chi-Town]

Isn't the e46 auto trans gm/pontiac though? With that being said couldn't you just have a transmission shop rebuild it? I know there has to be someone running some type of F/I on an auto trans.

[Mr Paddle.Shift]

I have to clear something up as well. So there are two models of Steptronic tranny available and the corresponding E46s.

A5S 360R GM 5

323i/Ci/Cic :6/98 to 3/00,323it:1/00 to 3/01,
328i/Ci/Cic:6/98 to 6/00,330Xi:from 6/00,
325Xi:from 9/00


A5S 325Z 5HP 19 ZF

323i/Ci/Cic :3/00 to 8/00,323it:from4/01,
330i/Ci/Cic:from 6/00,325i/Ci/Cic:from 9/00

A lot of people have disputed that the GM model is less than satisfactory compared to the ZF one. Fact is, the GM model is not a part that is taken off the shelves but a part BMW has modified. This is done through the GM Power Train Division of Strasbourg in France. Note that GM Europe and GM USA have very different design philosophies.

[crazy1323]

so how much power can the ZF transmission hold?