I was told that if two wheels weigh exactly the same...say 20 lbs. and one is 16" in diameter and the other is 17" that the 16" will yield a faster ET because of rotational mass...

heres my question. How much will a 21.0 lb 17" rim slow my 1/4 mi ET rather than the 16" wheels I have now that are 19.6lbs I believe

or how about a 27 lb 18" rim

 

I don't have a definite answer but I'd guess a tenth. You also have to take into account that 8" wheels need 18" tires and 18 tires tend to have stronger (read: heavier) sidewalls, hence heavier tires(not to mention the extra inch all the way around).

Kloogy runs 14.8 in his 2k2 auto with 19s so I guess it depends.

 

yeah i was thinking about .1 sec too.

 

The difference between the 2 wheels you are looking at will be minimal. So minimal that you would never be able to tell whether it's your driving inconsistency or the weight of the wheels affecting it. Not to mention you didn't say what the tires weigh. Tires are usually heavier than wheels, and not all tires weigh the same.

In going from a 37lb wheel/tire 17" combo to a 30lb 15" wheel/tire combo I improved .1 second and 1mph on average. You are changing the weight a TINY fraction of the change I made, you won't be able to tell a difference one way or the other.

 

My Combo for this season is a 12 lb wheel and a 11 lb slick, total 23 lbs so I should go Mega fast.

 

I run an 11.5lb wheel with a 13.5lb slick net result 25lbs.

Jime what wheel are you using?

 

I haven't got the wheels yet, still waiting but they are Rota's. I am looking for a lightweight combo for the rear to, I may just get a couple of millenia wheels and some real small light tires for there.

 

Im debating on selling my 17 pound volks and slap on my stock alloy 15's thats around 15 pounds give or take with drag radials since i want to concentrate on this up coming race season. So your saying it isnt worth the change and i should keep my 17's?? seriously every .1 second faster sounds a hell of alot better than .1 seconds slower

 

yeah i think you should get the 15s and sell the 17s to me