Quote:
L18_B110 wrote:
Quote:
Datsun1000 wrote:
Hi Guys,
Can tyre size affect rear wheel horsepower?
The basis of the question
If you put a car on a Dyno and perform a run and then chage the tyre size up to a larger overall size, will the rear wheel horsepower change.
excluding the very small fraction of a friction increase by the larger tyres.
Cheers Guys,
A link to proof or actual mathmatical proof for a yes or no answer would be appeciated.
no, tyre diametre will not affect bhp on a dyno. tyre diametre is just another form of gearing. and gears are torque multipliers. a taller tyre (or gear) will mean less torque (tractive effort) at the wheels, but they will be turning at a proportionately higher speed, so no net change to the power. eg change to a 10% larger tyre will make 10% less torque, but it will be going 10% faster at the same time, so it all balances out.
power = torque * speed / a constant
Below is what the retorted with
@ says:
so your saying that bigger tires need computer adjustment to multiply the torque change?
# says:
no that is not what is being said
@ says:
that is exactly what was said "torque multiplier"
@ says:
you need to change to settings on the dyno to adjust for the change in ratio
@ says:
so the ratio DOES make a difference
@ says:
otherise you wouldnt need to tell the computer the difference in gear ratios
Transfer
