[Eljeffrey13]

So the M5 has the 8hp75 the 75 is the tq rating
And the demon has the 8hp90 so the one in the demon is rating to hold more tq
I think the 75 means 750lb-ft
And the 90 means 900lb-ft

[DrivenAgain]

Originally Posted by Eljeffrey13

So the M5 has the 8hp75 the 75 is the tq rating
And the demon has the 8hp90 so the one in the demon is rating to hold more tq
I think the 75 means 750lb-ft
And the 90 means 900lb-ft

I believe they carry the hp76 now

[lixiang7349]

Originally Posted by DrivenAgain

I believe they carry the hp76 now

Here is what Wikipedia has to say.

"In the 8HP70 version, it has a torque handling limit of 700 newton-metres (516 lbf⋅ft), and weighs 87 kilograms (192 lb).[5]"

[pbonsalb]

Isn’t there is torque limiting in the software to help keep everything together during shifts?

[Eljeffrey13]

Originally Posted by pbonsalb

Isn’t there is torque limiting in the software to help keep everything together during shifts?

There is but i also know the transmission is built to also handle a certain amount.. some of the internals are stronger depending on which model u have

[pbonsalb]

Only 2 fitted to F90 — HP75 and 76, from what I have read

[Demon Barber]

Given that the car is pushing higher than 516 lb ft factory, makes me think the quoted 8HP75 torque limit either can't be right or they upgraded the internals to handle higher torque. Doubt BMW would put a transmission rated so low in a car making 553 lb ft claimed (actually higher in reality). Another concern that hasn't been discussed is the transfer case and its limits.

[pbonsalb]

BMW has put manual trans in cars before that are not rated for the official engine torque, like the GS6-53 in the F10 M5.

Maybe the factory software limits the engine torque under certain conditions in the F90 M5 or maybe there simply isn’t anything to worry about because the trans is under rated. We will know in a few years when the cars are out of warranty and the mileage is higher. So far even tuned examples that are a few years old seem to hold up, though there are a handful of reports of broken trans. Those may be due to aftermarket trans tuning that removes some safeguards.

[wrecklesswun]

ZF - 8HP75Z

[Ron1n]

The LCI F90 trans will handle 800lb/ft wheel torque. The pre LCI trans was rated lower, but we've seen time and again how ZF tends to underrate their transmissions, just like BMW underrates their power.