[coolman2527]

Hello all, does anybody know how much torque the ZF8 on our M40i can handle? I realized this can be a possible concern as I recently tuned my M40i and I'm wondering if the transmission can handle it in the long term...

So according to MHD, stage 2 can bring torque # to 600nm+, and I looked up stats on ZF8s, and only 8HP70+ varints have the capacity of 700nm+. Unless I am missing something here? Or TCU would automatically cut torque whenever it reaches the limit?

But then again, I also have stage 3 XHP flashed as well, which has the "Torque Limiters" removed, so does that overwrite the original TCU torque safety limitation?

[Keefy]

Originally Posted by coolman2527

Hello all, does anybody know how much torque the ZF8 on our M40i can handle? I realized this can be a possible concern as I recently tuned my M40i and I'm wondering if the transmission can handle it in the long term...

So according to MHD, stage 2 can bring torque # to 600nm+, and I looked up stats on ZF8s, and only 8HP70+ varints have the capacity of 700nm+. Unless I am missing something here? Or TCU would automatically cut torque whenever it reaches the limit?

But then again, I also have stage 3 XHP flashed as well, which has the "Torque Limiters" removed, so does that overwrite the original TCU torque safety limitation?

I have MY22 M40d, as standard it has 700Nm of torque, which is insane! I imagine the ZF8 Speed can handle a fair bit more than that.

[coolman2527]

Originally Posted by Keefy

I have MY22 M40d, as standard it has 700Nm of torque, which is insane! I imagine the ZF8 Speed can handle a fair bit more than that.

Hey Keefy, thanks for the reply! But for your case, I would guess your M40d came with the ZF8 variant that can handle 700nm, as diesel engines produce more torque, and no way BMW did not think of that.

But so far I spent some time looking and I haven't seen cases where people damage their transmission after tuning their ECUs, so I can only pray that the 500 nm transmission capacity rating on M40i is an extremely conservative number!

[suby01]

I came here. Saw NM talk. I left.

[coolman2527]

Originally Posted by suby01

I came here. Saw NM talk. I left.

Yeah it's real quite today

[Keefy]

Originally Posted by suby01

I came here. Saw NM talk. I left.

I forgot you US lads are ft/lbs only