What's wrong w/this tire idea?
 

I can't see what is wrong with this inexpensive way to "improve" the RX-8 for track use, and also improve street driving w/little consequence. So blow a hole in this idea, please :D I think this sounds pretty much like a win-win situation, or am I missing something?

Thanks :)

I know big wheels 19"/20" may be in style, and upsizing to a larger section width tire seems to be popular. Also, often those that buy these upgrades get new suspension pieces, coil-overs, or lowering springs, struts. Great for improved handling...But this all is expensive stuff and can cost $2K-4K, or more.

It seems to me the following provides even more benefits than just bigger wheels/bigger tires/lowering without the expense :confused: Pls focus on the idea, not the specific tires I choose, although the wheels or smthg close to them in weight is important.

So, rather than get larger wheels, get smaller, as an example, Kosei K1 TS 17x8" only 15.4lbs, a 6-7 lbs saving over stock! That's a big saving in unsprung weight, and rotational weight (good)

A couple other imspired features of these wheels:

Dual valve stems (one inlet-one bleed) facilitate the use of nitrogen gas for racing applications and the wheels use a Super-Formed rim section exhibiting characteristics similar to that of a forging w/o the cost. Downside, it may not look as good as bigger. :rolleyes:

Here's where it seems to get even better, check out the cross section picture. For example, using 245/45x17 GoodYear Eagle F1 tires, they are wider than stock (good), and w/lower aspect ratio (good) however the tire's overall diameter is smaller, so the car automatically gets lowered by .6" (good), so center of gravity is lower (good). Bottom line we're lowering the car without new springs or shock purchases.

The tires likely weigh less too, so there's NOW maybe a total 10+ /per axel weight reduction! That has to be good, yes?

Now actual speed in-car reads 4.8% too high due to the diameter difference, maybe a little inconvenient but.... We also just got an effective higher numerical rear axel, with faster acceleration, at the expense of less top speed by roughly 7 mph (141 vs. 148 mph). I don't think I'll notice that too often. But I likely would notice the faster acceleration at lower useable speeds.

That seems like a LOT OF POSITIVES for JUST SMALLER WHEELS AND TIRES. Help! I'm thinking I should do this. :)

wont a stock car float just as much? if so, because of the lowering, could this be a problem?

We've actually discussed that idea in several different threads before. You are absolutely correct, in performance terms 17" light wheels with wider tires is absolutely the way to go. Better handling, better ride, better acceleration, better braking control, there are no downsides. On the cosmetic side, the smaller diameter tires will not fill the wheel well as nicely as a slightly larger tire, but that's the only significant negative of any kind. I've written last fall about how my 17" winter wheels (Konig Holes), ~17 lbs ea IIRC, with tires are 6 lbs lighter than my OEM 18" wheels/tires, and that the improvement in ride and responsiveness is very noticeable from the lighter unsprung weight.

Regards,
Gordon