Just a quick recap on the GS6-37BZ transmission and how it's holding up, as well as the Z4 non-M 3.64 Diff (with a Quaife).
I have no idea how much longer these two will last, but:
- I'm on my 2nd transmission. 1st one lasted ~155 20 minute HPDE sessions before it blew. I am pointing the finger at heat. I've since installed two oil coolers and a pump, keeping it below 230F. Latest transmission is at ~70 20 minute sessions and going.
- I'm on my 4th? diff, this latest one is on ~49 20 minute sessions. Again, added larger oil cooler and pump.
I'm not sure if the cooler fluid will extend the life of these any further, but I'm at 630+whp for all of these events. I do not launch the car.
I think it's safe to say these two can handle 630whp with quite a bit of abuse. I went into this thinking the transmission would be a box of marbles but it's somehow holding the power. Perhaps don't spread this secret because I need spares to exist
The diff is smaller than the Z4M, and I may upgrade the entire rear end at some point. I'm itching to bump this to 700whp soon because why not.
I do wish there was someone else with evidence of power limit on this transmission. Doesn't seem to be much data out there...