Does anyone have a link with some sort of proof about lighter wheel performance including somesort of numerical function, such if you have this weight rim moving down to this weight will have such numerical results.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cbmprelude &raquo;</TD></TR><TR><TD CLASS="quote">Does anyone have a link with some sort of proof about lighter wheel performance including somesort of numerical function, such if you have this weight rim moving down to this weight will have such numerical results.</TD></TR></TABLE>


Neglect drag cause I am lazy and it won't change things.

Let:


T: torque at the wheels
I: total moment of inertia of the rotating parts
u: angular acceleration of the rotating parts
M: total mass of the vehicle
r: external radius of the tires
a: linear acceleration

T = Iu + Mra (1)
u = a/r (2)

(2) into (1)

T = I(a/r) + Mra
a = T[I/r + Mr)

Let R1 be inner radius of ring
R2 be outer radius of ring
m be the mass of the wheel.
I of a ring = 0.5m(R1^2 + R2^2)
I of cylinder = 0.5mR^2

So without knowing the actually weight distribution of the wheel wieght it is hard to give an exact % difference. But either way it seems you will see more effect from driving with a half tank of gas rather than a full tank.

it says here http://www.audiworld.com/tech/wheel13.shtml that adding about 10lbs of mass to your wheels is the same as adding 20lbs in your back seat.

There is also one last thing you need to consider "unsprung weight" that is how much your suspension weights, this determins how nice of a ride you will have as your suspension will be able to react quicker cause it has less mass to move/accelerate up and down.

Tire rack says that they tested lighter rim wieghts and they found better steering response. This could be very so because a lighter rim has less gyroscopic effect and can be turned more easily.

Cheers, hope that helps.