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      01-09-2008, 12:48 AM   #11
InJapan
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Drives: E46 M3 Cab, imola/imola
Join Date: Oct 2007
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I also saw the article. There is no mention about if the numbers were calculated or modified with coast down static drivetrain losses calculated. The article shows the car strapped to four Dynopacks at the hubs. The graphs appeared to be straight acceleration graphs with the numbers peaking at 508 ps with the exhaust and 485 ps in stock form. So, I'm assuming that drivetrain losses were not accounted for.

Unless someone has more information about how the test was done. You must assume that these numbers were at the wheel hubs. I'm guessing that Eric Hsu just mis spoke / typed.

You can also get a hint from what he wrote... 5% higher than other dynos... Dynopacks in general only lose about 10% compaired to 15% from a Dynojet because there are no rotational / frictional losses from the wheel and tire. If he meant flywheel, then he would have said 15% higher than other dynos.

Engine dynos... at the flywheel
Dynopacks... at the wheel hubs... 10% losses
Dynojet... at the tires... 15% losses
Mustang / Dyno dynamics... at the tires... 15-20% losses.

This is all approximations for a clutched tranny. Lots of other variables.

I am somewhat of a dyno expert. I arranged the distributorship of Dynojets to Korea.

Last edited by InJapan; 01-09-2008 at 01:08 AM. Reason: addition
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