Marinevette1

I've always wondered why the Corvette runs a staggered wheel setup (17" fronts and 18" rears) and what the benifits are to doing that? I also wanted to know why many Corvette owners decide to change to a "squared" setup and it doesn't seem to affect anything with the car? I am asking because I plan on purchasing a set of wheels soon and wanted to know which setup I should go with, either staggered or squared and the reason for doing so?

Please help!

AU N EGL

Cosmetics. Purely for looks.

the square set up is best for performance.

18" wheels all around slightly less width in front.

mcgilles

Sub

xtech

To avoid possible AHS/TCS issues, try to keep the rears approx 2-3% larger diameter than the fronts. Some cars will tolerate same sizes f&r, some won't. You can run 275-35-18s front & 285-40-18 or 295-35-18s rear with no issues. Not much selection in 285-40's though.

Nobody seems to know why some cars are different.

Take a look at Bill Dearborn's post towards the end of this thread:

http://forums.corvetteforum.com/c5-t...d-finally.html

Try to ignore all the bickering in the middle.

Solofast

Actually it was done for aerodynamics and ride. When the C5 was being developed, they wanted skinnier tires on the front to reduce aerodynamic drag.

They went with a 255 width tire in the front of the base car (which I told the chassis development engineer at the time was too small), primarily for aerodynamic drag (after they came out with the Z06 and the 275's up front he sheepishly agreed with me).

Becasue they had more power than a C4 they wanted more tire in the back to help put it down (which was the right answer). Since the front and rear wheels were going to be different anyway and you couldn't rotate the tires or move tires from front to back, there wasn't a requirement to make the wheels the same diameter. Moreover, a 255-17 rode a lot better than a 255/18 of the same rolling diameter and there are a lot of customers who woudn't have accepted the ride of the bigger wheel and low cross section tire.

Everything is a compromise, and this is just one of them.

vetteman741

Base front tire is 245 wide

Bill Dearborn

If you read the book "All Corvettes are Red" you will see it was purely cosmetics. The chief designer is quoted in the book stating that is why did it. The development engineers didn't want staggered wheels.

The book is a provides great insight into the development of the C5 and the reasons things were done. The author had complete access to the design team and internal GM meetings, etc during the design of the car. Lets you see how the management team had to lie, cheat and steal to get the car through the GM bueracracy.

Bill

vetteman741

I guess I will have to add that one to my Corvette book collection

jrose7004

All Corvette Are Re is a great read for any Corvette Guy or Gal!

Solofast

Oops, that was just from memory, I recalled it was a bunch skinnier than what we had on the Z07 C4's that we were racing at the time.

The engineers wanted 17's all around for weight and ride reasons. The aerodynamicists pushed the front tire width down and with the sizes and widths the ride guys couldn't make it work with anything bigger than a 17. They struggled with the skinnier front tires but were able to get the handling back with the skinnier front tires after they increased the roll stiffness of the rear suspension (compared to the C4) and to keep the back end in line they added more rear tire.

The fatter rear tires looked better on bigger rear wheels. The styling guys wanted the bigger diameter on the back for looks reasons. The ride and handling guys didn't want the bigger wheels because they were heavier and the lower profile tire didn't ride as well.

The styling guys won.

Cybermind

Purely for looks.......hmmm. I guess looks are more important than performance when it comes to Formula 1 and Indy cars? Yes, they also have a very evident staggered wheel setup along with some of the highest performance sports cars sold today.

It's obvious that there is a performance reason for it. That may have not been the main factor for GM choosing a staggered wheel setup for the C5 but it doesn't mean that there was no performance advantage in the end.

Solofast

To reduce inertia you want the smallest wheels and tires that will do the job. If you have a car that has most of its weight in the back you can use small tires in the front and gain some performance advantage in terms of acceleration by using smaller wheels and tires up front. The classic formula cars of the 60's had relatively small tires in the front because they didn't have any weight in the front and didn't need big tires up there. In a front engine car like a Corvette, the front wheel and tires are sized by how heavy the front end is, how much brake you need, and how much tire you need to get the front end to grip. The rear tire width is important, but if you can get enough width and enough tire in the back the car will have better acceleration and better ride with a smaller diameter wheel.

Bigger wheels aren't necessarily better. There is no performance advantage to bigger wheels, other than the fact that you can fit bigger brakes inside bigger front wheels. They weigh more and the shorter tire sidewall makes the tire much more susceptible to damage from potholes. Finally the bigger wheels and short sidewalls ride like crap.

F1 and Indy car wheel diameters are set by the rules. They are what they are because the rule makers say so. Not for any real reason other than to contain costs. If there were no rules the front wheels would be bigger in F1 to allow bigger brakes. Since the front brakes do most of the work the F1 designers would want bigger wheel diameters on the front than on the back.

Look at LeMans cars. They are running huge front wheel diameters to allow them to put on bigger brakes.

For some cars (mid engine cars with no downforce) a smaller tire in the front is an advantage only because they can reduce the weight and rotational inertia with a smaller front tire. For a front engine car there is no advantage in a staggered setup, and in fact lots of Corvette road racers use a square setup because there is an advantage in that.

webelo

If I remember right, the engineers wanted smaller/narrower tires to meet aerodynamics/MPG criteria and the designers wanted larger tires for aesthetics. The compromise was 17s in the front and 18s in the rear.