[Shotimes] (OT) Rotating mass and dyno tests

[Carl Prochilo]

I seem to recall a similar thing happen on a 96 SHO with Borla exhaust and
bigger wheels in one of the car magz.
-- 
Cheers,
Carl Prochilo
92 Ultra Red Crimson

On Wed, February 2, 2005 12:54 am, Ron Porter said:
> Last night, Speed had an episode of Sports Car Revolution. One of the
> segments dealt with the Mugen Acura that they are modifying. I had not
> seen
> the earlier episodes, but in this one, the installed bigger brakes and an
> exhaust system.
> They were expecting about 5 whp for the exhaust, and when they ran it, the
> car lost 7 whp. They reinstalled the stock exhaust, and then lost 12 whp!
>
> What they determined is that the larger brakes caused the net 7 whp loss,
> as
> these were the only changes. I didn't catch which brakes they installed,
> but
> they had bigger rotors, and although each corner's total brake weight
> (unsprung) was reduced by 1.9#s (probably most of it in the caliper
> weight,
> I would guess.....they didn't break out rotor/caliper weight differences),
> the bigger diameter rotors added more rotating weight by moving the mass
> farther from the center of the hub.
>
> When modifying your car with either bigger brakes or heavier tires, it
> "will" have an effect and a heavier wheel/tire comb will have a greater
> detrimental effect on whp than larger rotors.