Online Horsepower Calculators

When i used the calculator to predict my et from my mph it was alway off!
Not because i had traction issues but because it wouldn't 60 foot.

The calculator said my car should run 13.7 but my best time was 14.10(usually 14.20s)
The problem wasn't tire slip but just the opposite. Not enough converter for the cam i was using. 60' time were it the 2.2-2.3 Calculator said i should have been 1.9 60 foots.

There can be many reasons why the calculator isn't accurate. and this is just another reason why!