As the topic stated.... will the HP numbers be affected by different sized rims/wheels?

I'm sure the smaller wheels (14" / 15") with smaller tires will be lighter and easier to spin-up compared to 17" or 18". Just curious if the size/perimeter of the wheel affects the dyno HP readings...

 

yes my friend, it does. think of it this way. a wheel is nothing more than a lever that spans 360 degrees, if that makes any sense. hmmm, imagine the difference between using a small ratchet to take off a lugnut or using a breaker bar. you're applying FORCE to the end of the wrench to obtain enough TORQUE to loosen that lugnut. the greater the length of the wrench, the less force you must exert to get that result. this is the same principal that must be kept in mind when contemplating this issue, only reversed. since the torque is being applied from the rotational axis, and not the line of action(the road), the greater mechanical advantage will result from a shorter lever or smaller wheel. more so than the decreasing of the weight, the leverage is where it counts. that's why most drag wheels you find are a meager 13". i run konig heliums and they kick ***. they only weigh 10lbs a peice, and were way less expensive than the 17" ones i used to have.