[Schmidty_]

So just looking at a few options out there for differentials, I understand we have the quafie, MPP LSD and wavetrack options. What if we were to use an Active M Diff from the F8x, it has variable lockup rates by using an electric motor. I am just looking to see if anyone thinks we may be able to code it and have the car control it or activate it off a switch. Should be able to bolt up since it is the same used in the M2. Also did I mention these can be found salvage low miles for around 500-1000 bucks.

EDIT: Looking at the wiring diagrams it looks like it would be a chore to integrate the bosch computer controller into our system. However the way the motor only rotates and holds a cam, it looks like we could have full lockup activated by a switch. Maybe even splice into a trigger wire that is triggered when the car goes full DSC and TC off...

[Dylan86]

F8x setup sounds ghetto, unless you were to wire in the OEM harness/Diff ECU, yaw sensors, etc. Also, you wouldn't want this to act like diff locker, that would be a waste of time and effort, imo..

I doubt you'd save any money retro fitting an active diff. Might as well buy an F8x car if that's what you want. Otherwise the Wavetrac LSD is your best and most cost effective answer (imo).

[Schmidty_]

The big thing I was looking it with it is obviously you can turn it up to full lockup, but you have the ability to turn down the pressure on the clutch packs.
It would be as simple as having a rotary switch that runs current of .5 A or less to the motor, giving you freedom of how much "lockup" you want. If you want the car to behave similar to stock turn the knob all the way down and have a full open diff, if you are auto crossing turn it halfway up and you now have a limited slip, if drag racing turn it all the way up and mimic a spool.

[Dylan86]

Originally Posted by Schmidty_

The big thing I was looking it with it is obviously you can turn it up to full lockup, but you have the ability to turn down the pressure on the clutch packs.
It would be as simple as having a rotary switch that runs current of .5 A or less to the motor, giving you freedom of how much "lockup" you want. If you want the car to behave similar to stock turn the knob all the way down and have a full open diff, if you are auto crossing turn it halfway up and you now have a limited slip, if drag racing turn it all the way up and mimic a spool.

I had an entire rear end operate off of a switch, on an AWD Haldex drag car, and it's just not practical on a DD/ street car, trust me.. Also, unlike your 2 series, that car was worth more in parts, than as a whole... I honestly can't see this coming to fruition, within your expectations for cost/ ease of install.

You want to be able to drive your car and have it perform on demand, the same way, all the time. In theory, the concept of your vision makes sense, and "could" be done, but I don't think it will be anywhere near the cost to justify the effort. Sometimes being different, isn't better...

[Taunto]

Working at the dealer.. I did my fair share of rear Diff Recalls in the M2,M3, and M4 cars when they came through... I thought about putting one of those diffs in my car...But before you even think about wiring and codeing and retrofitting.. the diff its self will not fit.. Its a completely different rear subframe Not worth the time