Hey guys! I'm pretty new to tuning and i have a little doubt and maybe you guys could clear it up for me.

I'm currently looking at how to calculate the maxium HP a vehicle can do

I've done some researching and appears that the formula is:

(RPM * Torque) / 7120 = HP

However looking at manufacturer specification for lets say,Honda Accord 2.2 ctdi, the maxium HP should be 140hp @ 4000rpm.

Looking at the Torque Limiter map (stock), 4000rpm is 314 nm.

So (4000 * 314 ) / 7120 = 176 HP which is not correct by manufacturer specifications.

Maybe im misunderstanding something?

Thanks in advance.
Best regards,
Ruben Teles

internal engine torque and wheel torque are not the same thing...there are losses

I also think its 5252 and not 7120

5252 for torque in lbft , 7120 for torque in nm

Formula is in attachment.
Manufacturer Horsepower is measured on wheels
where this formula gives HP at crankshaft.

5252 / 0.73756 = 7120 as i stated above for NM, your formula is just longer but same

dadoom wrote:Manufacturer Horsepower is measured on wheels

wrong, manufacturer always claim flywheel numbers.