7at11

What do stock 16" 3rd gen rims weigh? I just called on 18" Miglia's at 26lbs each.

DamonB

26 lbs? Eeeeeeeck. I think the stockers are about 15 lbs. Do a search, I know it has been posted before.

7at11

Yop found it this time... about 15-16 lbs on 94+ supposedly... anyone remember the forumla for rotational inertia? Ahh, a co-worker helped me out. Hmm.. for an annular cylinder (a tire/wheel doesn't have a consistent mass distribution as required by this forumla, but oh well)

Rotational Inertia: Tire
I=(1/2)M(R^2+r^2)
R=outer radius
r=inner radius
M=mass

Rotational Inertia: Wheel
I=(1/2)M*R^2

May yield some rough comparative data for tire/rim changes if you know the masses, but realize the non-standard mass distribution of the two will produce an imperfect result.

Now if I could run some numbers on effect change in 1/4 time...

maxcooper

I weighed a bunch of stock rims of one style (flat back of spokes, the less "webbed" ones) and they all weighed 15.8 lbs.

I think the other construction style looks lighter, but I haven't had them without tires mounted so I could weigh them.

-Max

Brad Fielder

I think that for every 100 #'s you can lose off of a car you are suppose to reduce your 1/4 mile time by 1/10. But adding/removing unsprung is supposedly a 10:1, or 1:10. If you remove 10#'s of unsprung weight it's like getting rid of 100#'s of sprung weight. But there are other factors to consider generally when you get aftermarket wheels you get wider than stock tires in the rear, so you should get better traction off of the line. Another saying I remember is that if you are 1/10 faster in the first 60 ft., then you'll be 2/10's faster at the end of the quarter mile. Any one else have more/different info ?
Brad

xeVen

Install a T-88 and a 3 row FMIC... you'll be tons faster after that....and you'll be adding weight wow!

Jerk_Racer

Hmmm, if my '89 T2 were making stock power levels and I took off 2500# I could maybe hit mid 12's. :p

jerk_racer@hotmail.com