Thread: M3 dyno
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      02-23-2013, 08:35 PM   #10
JerezblackM3
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Drives: e92 m3 dct
Join Date: Apr 2011
Location: lebanon


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Quote:
Originally Posted by BMRLVR
Quote:
Originally Posted by CanAutM3 View Post
"Wheel torque" as expressed here is a number that does not exist in real life. The actual wheel torque should be multiplied by the gear and final drive ratios.

The torque numbers presented on dyno charts are simply calculated from the wheel horsepower and engine RPM to represent an "equivalent" flywheel torque number. The real flywheel torque number is actually higher as it does not see powertrain losses.

Either you show wheel torque multiplied by the gear ratio or flywheel torque without the drivetrain losses (which you cannot measure wihout removing the engine). Anything else is a fictive number.

Torque numbers as presented on most chassis dyno charts should only be used as a reference to get an idea of the shape of the torque curve.

I would not dwel too long on the absolute power numbers, even less so on the absolute torque values of the dyno runs. Rather focus on the relative before and after runs to see how much gain you are getting from mods.
+100000 Even in direct drive (4th gear MT 5th gear DCT) the FD is still multiplying torque. Most people don't realize this!!!

To the OP, I think your numbers are high and I have not seen NA torque numbers from and M3 that were that high on a chassis dyno....... The numbers are probably off a bit.
Yes I believe so too, but incredibly, a rally driver and a drift champion who owns an e92 and has a BMW m power maintenance shop tested my car and was amazed with the torque it made.