HP vs Gear ratio question

[Don Hardcastle]

Ok,
I did the dyno drag thing at the Harley shop last night. The bike made 147.64whp in 6th gear.

The ratio for 6th gear is 1.043:1.

We do whp runs on these things in 4th gear. That ratio is 1.285:1. I can't seem to figure out the equation that will tell me how much whp my bike is making in 4th gear.

Any help??

Don

 

[Don Hardcastle]

anyone??

 

[Red05]

I might be way off, Don, but if the RPMs are the same in each gear, I would think that HP numbers should be the same.

 

[Spike]

Two things must be known to calculate HP, Torque and RPM.

HP = (Torque X RPM) / 5252

OR

Torque = (HP X 5252) / RPM

You can probably use the gear ratio to figure out your RPM's but that still leaves you needing your torque number.

 

[Professor]

Don was that peak HP or the HP at max mph?

 

[Commuta_Busa]

gearing doesn't effect your engines hp... wheel thrust is effected by the gearing. This is derived from the engine torque.