Rim size benefits?

[ScotcH]

Hello,

Some questions regarding rim sizes. It seems that mostly 15" and 16" are in use by Solo 1 competitors. However, when watching production car racing on TV, it seems they all run pretty low profile tires (larger rims)

So, what are the pro/cons of a larger rim size? Is it weight? Cost? It would seem that a lower profile tire would perform better, no?

I have yet to pick up some rims for my track tires, so any input would be appreciated. I know weight is definatly a factor. Are there others I should watch for?

Thanks!

[rainman]

There may be a couple reasons why larger wheel/lower profile are used by pro series:

- Need larger wheels to clear lerger rotors/calipers
- Series rules (read sponsor deals) mandate the use of a certain wheel or tire

[pokey1]

Besides bigger brakes, they have budgets / sponsors that allow them to get lightweight (read EXPENSIVE) wheels.

[ScotcH]

Hmmm ... ok, so in terms of performance, what is the effect?

eg: I'm looking at a set right now. 16x7, 15lbs or 17x7, 16.5lbs. Would the lower profile tire benefits outweigh (no pun intended) the added wheel mass?

[rainman]

Are you planning on running R compounds? If so, you'll be hard-pressed to find low profile tires in a 17" configuration and if you do, they will be significantly more expensive than the more common wheel sizes.

[pokey1]

If it's the same wheel (make) then I would personally go with the 16". 1-1/2 lb is 1-1/2 lb and you'll save on tires too.

[ctenche]

The rule is to go for the go for the smallest, lightest and widest wheel/tire combo you can get. Weight is way more important than tire aspect ratio. If you're looking at the BTCC cars or the JTCC cars then remember that 1) the cars have gobs of power to deal with the heavier wheels/tires and 2) they use slicks which is an entirely different thing.

Also, keep in mind that a bigger wheel requires a bigger tire which also weighs more and obviously costs more.

[GregR]

I've gone through this same hair-pulling exercise for probably 2 months, and I'm guessing the 16's and 17's are Rota rims? Nice and light and cheap, but I'd rather get something stronger for race use (they'd be fine on the street, though).

I was close to using 235/40-17 R's, but the rim availability was so slim that - well, the only things available were damned expensive or damned heavy (17x9's)..... I'm ending up with 225/45-15's on 15x8's which are light and cheap and strong (but look like snot).

[ScotcH]

The 16x7 I have in mind are Rota slipstreams, Team Dynamics Pro Race 2, and SSR integrals. They are all fairly cheap (the SSR's are used). I'm not sure I can do 15s ... the stock size for my car is 215/55/16. I was planning on running 225/50/16, which on a 16x7 rim should be nice.

What did you end up getting, and since you're also in Ottawa, can I ask where did you end up buying from? What about tires? Same place (package deal)?

Thanks!

[GregR]

I'm in Ottawa, but bought my stuff all over the place. I drive a 5th Gen Prelude, and my factory size is 205/50-16.

For rims, Circle Racing Series 82, 15x8's. $192 US each, bought direct from them.
For tires, Kumho Ecsta V700 225/45-15, from Wheel&Tire Zone, $190 Cdn each.

I know one guy who is running 16" Slipstreams but he doesn't autocross it - he's a drag race kinda guy.