using larger (Dia.) wheels/tires, rotating mass effects Options

[Tom]

Have we ever discussed the effects of changing the wheel/tire sizes and the effects on acceleration, both in starting and stopping? I ended up using 195/55/15's on mine and I noticed that the speedo was off about 10% and I expected that and because the overall diameter was smaller, i thought acceleration would be affected slightly also. What I didn't take into account was the rotating mass effect. So, I guess my starting and stopping both have been slightly improved, maybe handling is improved slightly also.

Link to some info: http://www.the-welters.com/racing/rotational.html

I some times wonder how those pickups with 22" wheels brake in an emergency!
Tom

[strawman]

Several years ago, I built my '85 Toyota MR2 SCCA C Street Prepared car using 13"x9" Keizer wheels to both reduce the rotating mass and to lower the effective gearing. It was certainly more lively in comparison to the skinnier/taller stock wheels and street tires that I used to drive to events. A lot of the Miata guys used the same logic, until a couple of years ago when Hoosier came out with some WIDE 15" tires -- then almost everyone abandoned the 13-inchers. The newer logic is that the slightly greater rotating mass was worth the extra width of the taller tires. That being said, I'll be running 16x9 and 16x7 wheels on my Suby-powered teener.