clemsondave

How important is the weight of wheels to performance (acceleration, braking, top speed, etc)?

I found some wheels that I really like (Ruff Racing 278s). I am still trying to find the weight of the 18 x 9.5 and the 17 x 9.5s, but the 18 x 8.5s are 28.5 lbs each without the tire. Is that heavy? I am guessing that the 9.5s will be around 30lbs or so.

SJM Manufacturing Inc

iTrader: (5)

Not only is the overall wheel weight important, but how the weight is distributed.
Moment of inertia is greatly affected. Additional power required is going to be proportional to a higher moment of inetia at acceleration. Another negative results will be longer braking distances.

More mass moved towards the center of rotation will result in faster acceleration with less hp and less braking distances.

I can ramble on some physics and math formulas for you, but I don't want to bore you...lol

In closing, overall weight IS very important and also WHERE the weight is placed in relation to the center of rotation.

2002BlackSS

iTrader: (4)

Because he didn't include the formulas, I feel this is also needed. The moment is decreased if the weight is focused closer to the center of rotation. Therefore, the ideal wheel would not only be light, but have most of it's mass centered around the center.

clemsondave

Thanks for the input.

I guess my question is more specific than I mentioned. Would 30 lb. wheels make a noticable difference from the stock SS wheels? I think the stockers are apx. 22 lbs

SJM Manufacturing Inc

iTrader: (5)

Yes, general rule of thumb without running through some equations ....this is a GENERAL rule...for every 1 lb of added rotational weight...is like adding 4-8 lbs of static weight. You'll probably loose ~.1 of a second...your 60 ft times will be slower and you will take longer to stop. More then likely if you did a quick change and tested back to back, you'll probably notice a difference in acceleration and deceleration.

2002 thanks for clarification of my statement

"More mass moved towards the center of rotation will result in faster acceleration with less hp and less braking distances."

...it may have not been clear to some.

Case in point...look at our P2 rims...true they are lighter in overall weight...BUT most importantly if you notice, the center sections are smaller in diameter (where most of the mass actually lies and the rim shells which are the furthest point of the rim are a different mill thickness).

2002BlackSS

iTrader: (4)

I think I completely skipped over that part of your response! Oh, well, like you said,

LS1_PNYTAMR

iTrader: (1)

this is a good thread... any idea how much a weld prostar or dralight drops off the front end in size 15x3.5 or the stock 16x8's with 245 tires.... also how much on the bogarts.... im talking actual wieght.. like 20 lbs ect, then it will give us an idea of how much ur also dropping rotational wise.. i intend to post this on another board local where a lot of us discuss such things..

also if u dont mind, post the actual formulas.. i was trying to look them up the other day!

WickEdSix98

iTrader: (4)

My stock 16x8" wheels w/245/50 tires were 42lbs. My 15x3.5" draglites were 25lbs in the front with tires and the rear 15x8 with 275/50 BFG DR's were 42lbs.

lou23

My Z06 18x9.5 wheels are 22 without tires, haven't weighed them with the 275 35-18's yet.