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Old 09-13-2012, 09:08 AM   #14
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Originally Posted by Outlaw5.0 View Post
Comparing engine Dyno to chassis Dyno is impossible without knowing the actual drivetrain losses. Maybe the loss is less than 15-18%?. The 2013 GT500 is a good example of reduced losses. Lets not leave out dyno accuracy. If believing the ST makes 267 horsepower or what ever makes you happy, then so be it.
Right, we can't know exactly how these real world numbers compare to the crank numbers, because of the uncertainty in drivetrain losses. Dyno accuracy and peculiarities are mitigated by the sampling of many different dyno's and averaging the results out. Of course we only have a small sample to deal with, but it's a start. So, even if we assume a 10% loss, the numbers still look good:

Average HP: 227.04 x 1.11 = 252.27 HP
Average TQ: 276.316 x 1.11 = 307.02 ft/lbs

It certainly seems as though the torque number is being underrated. By quite a bit.

(Aside: hopefully we all realize why I'm multiplying the whp/wtq by 1.11 instead of 1.10 for a 10% loss, and 1.18 instead of 1.15 for a 15% loss. Can explain if necessary.)
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