XC6VETTE

Anyone know what the stock wheels weight?

Alex Levy

Fooking heavy.. thats all you need to know.. Around 28lbs front and 29lbs rear.

XC6VETTE

Thanks very much for the info. However, I'd like to understand more. In general (I think) I understand that not all vehicle weight impacts vehicle dynamics equally....that reducing a pound of sprung weight (wheel/tire.brake weight) is roughly equalivalent to reducing total vehicle weight by 3? pounds or more. This multiplier effect is important because with lower wheel weight the suspension is having to do significantly less work...and thus allows it to do it's job more effectively. (i.e. react more quickly to keep the tire on the ground.)

However, since the C6 engineers designed the suspension (spring rates/geometry etc.,) for the stock wheel/tire/brake package...shouldn't the spring rates as a minimum need to be adjusted in accordance with the reduced sprung mass?

Anyone....?

PS If I focused on loosing 50 pounds I'd see improvement as well...but, back to a more realistic option!

shopdog

The biggest thing that lighter wheels/tires does for you is to reduce rotating inertia. This lets the car accelerate faster, same as if you went with a lighter engine flywheel. A few pounds can make a big difference. Lighter wheels/tires can help with suspension compliance too, but not all that much. More flexible sidewall tires will make a bigger difference in keeping the tires in contact with the ground.

XC6VETTE

That makes sense to me. Thanks. You mention acceleration...that sounds right from what I remember of Physics (F=MA).

So, if suspension compliance isn't biggest benefit...and acceleration is...then reducing rotational mass (inertia) is key to optimizing acceleration. Following that logic would indicate that weight at the wheel hub isn't as detrimental as weight at the outside diameter. Thus you want the lightest rim, and perhaps even more importantly, the lightest tire possible.

So, what I don't know is how much each element contributes...I guess I would only need more discrete wheel/tire weight info to figure it out. ANybody? For eample, you might get the most bang for your buck by simply changing to non run flat tires!?

In terms of rotating mass...which is better on a C6...18/19 or 19/20 assuming the same type tire/wheel in each case? How much difference would it really make...is it significant or negligable....assuming all other things being equal? I understand racing tires don't yet come in anything bigger than 18"....what does that tell us?

I'm just trying to quantify the difference and rank top to bottom their effect on performance. Anyon care to chime in?

shopdog

Smaller diameter is better, same reason as why hub weight isn't as important as rim weight, shorter torque arm. But, if you want the same ride height, you'll need a taller sidewall tire to make up for the smaller diameter wheel, and that can add weight back where you don't want it.

Better is low profile tires on smaller diameter rims, then control ride height by using the ride height adjusters. You can go up at least an inch from factory stock on those, so 17 inch fronts and 18 inch rears are practical, maybe even 17 inchers on the rear too. Big advantage to 17 inch rears is that good drag tires are available in that size.

I'd better add that 17 inchers in the front probably won't clear Z51 brakes, but they'll work with the standard brakes.