Quote:
Originally Posted by Pimpsy
Sorry, but this is not correct.
The ZF8HP75 is rated 750 max gasoline torque per the manufacturer spec. A stock M5 is about 550 torque so 20% more is not even close to max spec.
Aside from that, common sense will tell you that the cars are not designed to run at max stress. There is plenty of room to add extra horsepower and torque without destroying the drivetrain.
Much more important is how you actually drive the car. After all, BMW will tell you that even a stock car can be damaged by repeatedly using launch control.
Your basic premise is of course correct, which is that as you add power it will add additional wear to some extent. But I imagine if we pulled apart a stock drivetrain driven hard at 100,000 miles it would look worse than a race chipped car driven reasonably at the same mileage.
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No, I'am sorry.
The 75 is referring to 750Nm, not to lb-in. And it's referring to engine input, not to wheel torque output. This being said, the M5 is tuned to the max of the drive line from stock already. No slack at all, look at the competition which can't up the torque either for this reason while for a few hundred dollars you can chip to +900Nm. No room for discussion at all: beyond specification! PS, previous M5 was also on the verge of the specification of the transmission: 680Nm and full stop.
Of course, there is a design margin of ~15-20%, but it is not to be used for tuning, it's to be used for warranty risk by the manufacturer.