Xeon

Hi all,

I am just wondering,

does sizes of wheels affect the speed of a car?!...or acceleration?!

Mach430

Size and weight both affect acceleration. The heavier the wheel is, the harder it is to spin (or stop spinning). The larger the rotational mass, the more power is required to spin.

Iceman's C230

That's why people don't drag with 17" 18" 19" wheels. It reduces acceleration. They could but their times won't be good as let's say 15" wheels.

mdp c230k

Yes, as Mach430 said, weight makes a difference. Even more important is the diameter of the overall tire/wheel package. The gearing of the car is designed around a ratio related to the radius of the tire/wheel. Remember the tire/wheel converts rotaional force to linear force to drive the car. The size of the tire/wheel changes the relative torque require to turn it. A bigger combo will be harder to turn but more distance will be covered per turn, smaller is easier but less distance is traveled. The larger combo aslo puts more strain on the drivetrain components under acceleration. Stick with the designed size for reliability.

tommy

I think that Mach was talking about the rims only. Any good plus sizing will allow for keeping the overall diameter the same.

If I read his comments right, a larger wheel puts more mass further out from the center, which requires more force to get it turning. It's also not supported by the suspension (unsprung), so that has more effect on acceleration than say, an extra couple of pounds in the passenger area.

Width also has a similar effect on acceleration - more contact patch, more friction, but that has the benefit to handling, so you'd have to weigh the two against each other for a happy medium.

mdp c230k

Tommy,
I reread Machs comment and I think you're right. I wasted all that good ink!

tommy

It's only virtual ink, no biggie!

gab

Sport Compact Car Magazine did a test last year on how the rim size affect the track time.
They did a test with 14" 15" 16" 17" wheels and they turn out that 16" wheels has better performace with 15" very close and far better than 14". 17" are the worst.
their reasoning is that Plus Sizing increase the contact area and improve handling and therefore increase peformance on twisties. bigger heavier wheels might hurt straight line performance.

Well for drag racing u might want to use like 14" 15" drag racials on track u might wanna use slightly bigger rim size that will fit your brake!

Mach430

It is not the wheels or tires alone that are important, but the overall combination of the two. Even when downsizing the tire to compensate for a larger wheel, you are still slightly increasing the overall diameter of the wheel+tire. With a larger wheel comes a smaller tire (which typically weighs less). Personally, I think that a 18" or 19" lightweight-forged wheel is perfect. Depending on where you are coming from, you may make it easier to spin the wheels. The smaller tire wall of a large wheel helps handling a lot, and is another plus for going to a bigger wheel. It's the 19" 35lb+ wheels that will definitely slow down the car.

Xeon

Mach....

I am just wondering...i might be getting a Brabus V on my car...

My mechanic told me i might need fender modification..is that true??

I had already lowered my car with HnR....the brabus are 18'...what tyre size do you recommand? and what offsets?? i need some help here...don't wanna depend too much on him ( you know.....he know things that i don't...and can make huge bucks out of me..although he is a nice guy)

Xeon

Also..any updates on the kleemann?

Mach430

I don't think that you would need any fender modification. You can always roll the fenders afterwards if necessary.

trench

This is the main reason that touring race cars have such big rims. It's worth the trade off in loss of acceleration and increased unsprung mass (which effects handling) to be able to run larger brakes. Most people don't think of brakes when they think of racing cars but they are a key factor in reducing lap times.

Cheers, BT.