18 vs 16.

[adamism]

I have stock GSX rims right now; they weigh about 25lbs.

If I were to go to Rota Slipstreams 16" that weigh about 13lbs.

Would that make a considerable amount of difference in acceleration?

 

[DSMSpyder99]

its gonna make a HUGH diiferent if i did my math right thats -48lbs of rotation mass you should feel a improvment acceleration, cornering, and braking

 

[adamism]

Really? Someone told me it could improve your 1/4 time by .4 secs.

Anyone else have evidence to back this up?

 

[L2RTSiAWD]

Moved.

 

[wret]

Really? Someone told me it could improve your 1/4 time by .4 secs.

Anyone else have evidence to back this up?

Seems like a stretch. First 13 x 4 = 52 (not 48). Estimates I've seen of the equivalent of rotating mass to static mass are about 1:2, meaning a pound of rotating mass is like two pounds of static mass. So loosing 52 pounds of wheel weight is like loosing 104 pounds from the chasis.

100 pounds is worth about 8 hp in my power to weight book. I don't think 8 more hp will get you 0.4 seconds.

This is all speculation of course.

 

[greathuskie]

there is a 12lb difference between wheels, so its 48 lbs

 

[gofaster87]

I heard the ratio was closer to 1:5 from unsprung to sprung weight. So losing 48 lbs on your rims would equal to 240lbs on the track. That would be quite a difference.

 

[Twizzle]

tires have alot to do with rotating mass as well..... dont forget that!

 

[Bad93ex]

I thought slipstreams only came in 4 bolt arrangements?

 

[igs]

I heard the ratio was closer to 1:5 from unsprung to sprung weight. So losing 48 lbs on your rims would equal to 240lbs on the track. That would be quite a difference.

Actually it's closer to 1:1.5. So losing 48 lbs on your rims would equal losing 72 lbs of static weight, which is still a lot.

edit: I misread the original post. Unsprung to sprung is 1:1.

 

[ACM]

According to Herb Adams, it's 3:1, chassis weight to axle-speed rotating weight.

Charles

 

[its_hey_ma]

If i remember correctly, given a good driver and all, for every 100lbs of chassis wieght lost you can cut .1 sec off you 1/4 times