Quote:
Originally Posted by mr_lab_rat
I don't know why so many people are confused by this:
BHP - crank horsepower. Could be measured by engine dyno or calculated from WHP by adding approx 15%
WHP - measured by roller dyno like Dynojet or Mustang.
There is so much room for bending the numbers. Drivetrain loss is just estimated. Some people use 20%, some use 15%. The weight of the roller drum makes a difference. Dynojet typically reads higher.
Then there are corrections. Not every dyno operator uses them correctly. A 300 whp car can pull 330 on a cold day and 270 on very hot day. Uncorrected numbers should never be used but often are.
One time I got a pull done and the numbers were about 10% more than I expected. The operator said he had the Mustang dyno in "Dynojet emulation mode" so it read higher.
So after all that experience I really stopped caring about dyno charts. When I do something to the car I dyno it at the same shop and try to pick a day with similar weather so the corrections would also be similar.
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All about them 1/4 mi times
