Alright I have a question for you guys about wheels on a car that I had an argumant with my brother about tonight.

I know I may sound foolish but here goes.

My older brother claims that if you take any kind of fast car (he used a dodge viper as an example) and take the same driver and everything and put 20 inch wheels on it as opposed to 15 in wheels it will beat it in a race whether it be drag or autocross.

He claims that the 20 inch wheels will get better traction and run faster than the 15's. I am asking you guys if that is true or if the 15's are better and why?

He was also trying to talk me out of buying the Type R and buying a car "with more cylenders". I myslef like the import scene while he was going on about a '67 mustang shlby gt and ignoring my explaining VTEC and the better build of then engine trying to bully me verbally because of the older brother thing.

Another thing he was trying to tell me was that someone such as an indy car racer will beat anyone on in AutoX event because they are supposed to be the best drivers out there according to him which I said wasnt true. As I went on about me wanting to AutoX for fun he continued on how its racing and how people that do that are sponsered by companies and me going on about how you guys are daily drivers.

I am rambling on but any answers to my wheel question or about the driver of the car such as an indy driver to drivers like you guys.

Thank You

Bryan

ps. he didnt talk me out of buying the R, I still am going to get one, even though I claimed it was rare he said he could call a dealer and a dealer find 50 R's if i wanted one (he is full of so much BS I wanna punch him sometimes)

 

First off, from what I have been told, larger rims = slower acceleration... Secondly, he sounds like he has seen "Gone in 60 Seconds" quite a few times.. Wasn't the main car in that movie a 1967 Shelby GT 500.. Don't listen to him, and get an R :: You won't regret it!

 

Well the "appropriate" size to me on any Civic/Integra are 15"/16". Yes smaller wheels are lighter than bigger wheels so that's why u accelerate and decelerate faster. U won't put too much "extra" work load to the engines and brakes. But not the bigger/smaller the better. U have to ask around what is "appropriate" on a certain car for example for Civic SiR and Integra GS-R, 195/55R15, 15x6.5 or 15x7 are pretty much the best setup u can know of. They're the most "appropriate" setup that's what I meant.

For the Indy car racer's case. Well yes they got tons of skills they know well how to control the car good in like 200mph+. But under auto-x they may or may not win. U're doing no more than 3rd gear most of the time in the auto-x. U have to steer, brake, accelerate at the right time to make the car balance better and have a better time. Two different cases anyway. Pls Indy car do oval track most of the time, u don't see them turning left and right on a course that much don't u?

 

Thanks alot guys, could any of you inform me why some cars are better with small wheels as opposed to others are better with big wheels?

thanks

Bryan

 

I was always told in physics class way back in High School, that bigger tires do not give any more traction than smaller tires. they can give more stability being wider and also help w/ the temperature and heat dissipation better, but no better traction.

You also have to keep in mind one thing. A smaller displacement engine has a harder time overcoming the additional weight for the wheel, where a Viper's V10 isn't really going to make a difference in the extra 8 lbs on the rear wheel. When you have 500 lbs of torque compared to 120, it's a huge difference.

 

Overall wheel size is dependent on so many factors. A Viper has large wheels in order to fit over the brakes and the width is needed for traction because of the powerful motor. If you were going to do a controlled test, where all wheels, no matter the width or height, weighed the same, then maybe the larger wheel will be the best, even though it has a larger moment of interia. (this is not taking into affect like wheel offset or any other suspension related item).


[Modified by davidnyc, 1:06 PM 8/9/2001]

 

Kick him in the nads and tell him he's F.O.S.

Accelleration is affected by the OVERALL diameter, so a larger rim will make little difference, though WEIGHT is the second factor. If you have a larger diameter rims that is the same weight as the original, there will be a performance gain in handling due to the shorter sidewall, but not necessarily accelleration. This is, of course, with the same width tire and same track width (not offset).

When have you ever seen professional drag cars with 20" rims? They use small rims and lots of sidewall & width to get traction. The tires flex, storing up some of that power, and help reduce wheelspin.

20" rims will come with a serious weight penalty on anything that did not come with 18" or 19" rims stock, unless they are forged or of some other light weight manufacture.

For every car, there is a point of diminishing return in going up in rim size due to weight. For the R, I believe 17" is it (and too large, IMO). Lightweight 16" will leave you with decent sidewall and slightly better handling.


[Modified by FBP_1171, 1:26 PM 8/9/2001]

 

There's another factor. Beyond a certain point, you're no longer going to be able to find tires with the same outer diameter. And when you get tires with a larger outer diameter, that's just like putting taller gears into your car. And taller gears mean poorer acceleration.