Take internet horsepower with a grain of salt

Often very high (sometimes unbelievable) horsepower numbers are published.

There are a few methods (wether applied intentionally or accidentally) to publish wrong results.

When you compare engines, before deciding to believe or not, it's a very good idea to

If the VE numbers for an engine at MAP=250 kPa and 9000 RPM (especially if it's 2 valve head :-) calculates to be higher than a factory variable valve Honda/Toyota at MAP=100kPa and 8000 RPM, start to doubt.

Consider 400m time

The measurements done on 2 different dyno's at different times deviate more than desirable for sane comparison. Even if there is no intent to publish bad data (from bad calibration or multipliers).

The best times usually tell much more.

TODO: find or build a program to closely estimate best times, using

I did a brutal C hack for estimating acceleration through the gears with a specific torque curve years ago. I guess that someone can find the formulas helpful when making one that is not configured at compile time. Note that the shift time is only additive, the time counter is only incremented which make the graph look a bitr wierd. It's simple to fix but it was outside the scope of the program. -Jörgen

Knowing the time and speed after 60 or 100m makes it all much more precise by largely eliminating the tire traction part.

Having RPM log of the whole run also helps a little (to find not only the area under - a certain RPM-range of - the torque-curve, but the shape of it too).

See also