Should I dyno with my oem 17's or lighter 18's?
 

I'm heading to the dyno today and I can't make up my mind which wheels I should use. On one hand my 17's are smaller and they have less rotational force. on the other hand my 18 inch SSR's are 5 pounds lighter but have more rotational force. I'm sure either way it won't make a big difference but what do you think will perform better? BTW the 18's are on right now :D

Heh at least you have the luxury to switch
 

I have the 17X8 Integrals, but I also have the Brembo Gran Turismo Kit. Can't go back down to 16's. I think it's easier to just leave your SSR's on. I'm getting my Max dyno'd on Monday at XS and I plan to leave my SSR's on...then again the Brembo rotors take a good deal of rotational mass off as well as the wheel.

*dyno with whatever wheels u had last time on the dyno then we can compare!



*fixed :laugh:

use whichever wheels you dynoed first in to get the 215 whp so we can get the exact gains from your udp and y-pipe:D If you have time change wheels during the dyno to see if it makes a difference

Use the same rims you used for the last dyno trip. That was the SSR's right?

Ditto the previous 3 posts

Ok, I will put the my 17's on the front then :)

Re: Should I dyno with my oem 17's or lighter 18's?
 

Dyno with the same wheels or get some light 15's to dyno.

I wouldn't bother with it then. Just dyno with the wheels you have on now. Your probably more intersted in the total hp than the # of gain. Thw wheel and UDP difference isn't going to be alot anyways.

I just put the 17's on so.. My last dyno was with 17's too.

Icm= MR^2
I is the rotational inertia of the system, M is the mass, and R is the radius. Plug in your info and whichever has the lower I is the rim that you want. Also remember this is only taking into consideration rims and not tires, and assumes that the mass is distributed evenly across the radius.
-hype

what measurement should R be in? or does it not matter what unit it is so long as both equations use the same unit?

same question for mass. doesnt matter just as long as both are the same, right? (when comparing)

waiting for those dyno results ewok post em up. its 8:30 here now:D

I personally would want a dyno that reflects the car I drive everyday, not the car I "prep" for dynos.

OT: Clayton ur rims are HOT!

:D Yeah - I love em...although they show off my not too pretty stock brakes.