Quote Originally Posted by Grayfox View Post
I am sure modern dynos have a input for gear ratio.

So you could do it in 2nd, you would just have to tell the dyno what the ratio is so it can give the correct results
It's to do with the losses coming from the other gears moreso than he ratio

A low gear (high ratio) will make all powertrain items (engine, trans,driveshafts etc.) spin faster than what it would with a 1:1 ratio, and the converse in a lower ratio (5th gear).

So to get the most accurate reading you use 4th.

Maybe it's worth dynoing each gear so you know what power you have everytime you shift

lol