I was thinking about new wheels for road races out on tracks. i heard that the smaller the wheel size the more torqe u get. so will 16" wheels on my 8 give me more performance gain or loss? i was thinking about getting 16" wheels 8 inches wide on some 40 profiles. some people say the the handling of the car will go down if i go with smaller rims, are there any truth to this? would appreciate some suggustions from the pros out there. oh yeah, mazda took first place in P2 class of american le manz this pass sunday, congrats to them. renisis engine starting out pretty good so far.

 

Well, depending on what brakes you got with your RX 16" wheels might not clear the calipers. Most people seem to run 17" wheels for the track. I believe the MT has larger rotors which will obviously make a difference.

 

please.... someone help..... i'm seriously thinking about buy some 16's. pm me if u know :o

 

you need at least 17's to clear the big brakes on the 6 speed cars.

 

cool, thanks, but what will happen performance wise? will i get some more torqe? will i lose anything in my handling? thanks again :D

 

the main reason people get smaller wheels for track is to reduce unsprung weight. Basically, the lighter the wheel/tires are, more power can be put down to the ground instead of wasted trying to turn the heavy-*** stock wheels the 8 has :D

LIGHTWEIGHT is the key, not actual rim size.

 

I see, very helpful. but i also wanted to go down on the size cause of the prices of tires on 18's, ouch. :p

 

It will be fine. Unless your a pro, you won't notice the difference betwen 45 and 40

Besides you haven't even been on the track yet.

 

You won't get more torque. There's no way a smaller tire will increase the torque output of an engine.

What it WILL do is help the car be at a higher RPM at a lower speed where HP/TQ can be accessed and put to the wheels more efficiently/quicker, by keeping the RPMs up.

I ran tires that were 1.5" shorter than stock on my old WRX which allowed the boost to come on about 300-500 prm sooner which meant torque was put to the ground about 500 rpm sooner.

But as others have said, without that much of a change in tire diameter or weight, you won't notice it that much. Here's a good calculator to show the average difference in diameter:
http://www.miata.net/garage/tirecalc.html

--kC

 

tracked my car twice, frist time i only had 4000 miles on it, with no lic plate. :p i still need like 10 more track days under my belt before i can start saying that i know what i'm doing of course. i don't mean that i'll get more torqe at the enige, i mean at the wheel silly. :D thanks everyone that replyed.

 

The only reason to go down a size would be to save money. For the most part the 17" tires are the same diameter or taller than the 18"s so you wont get any gearing from it.

 

same for the auto (sport pkg or higher). rear brakes may be a bit smaller on the auto, though.

 

ultimately a smaller diameter wheel/tire package can be lighter, but it may take a racing 3-pc wheel to get there. They aren't low cost and can be bent easily; a 16" x 8" wheel should be able to get down to the 12 - 13 lb range. You'd be more likely to get 3-pc 16" racing wheel to clear the brakes if that's an issue.

anyone ever try to fit the factory 16" x 8" FD wheels? They were in the 15 - 16# range as I recall. The pattern and offset should work, not sure if it will clear the calipers though.

 

I run Kosei K1 TS 8x17 with 255/40 Kumho MXs. Saves me 7.6 pounds per corner and the tires are cheaper. And the MXs are .8" smaller in diameter then the OEM tires.

 

you can still get the Kumho Victoracer in 255/40-17 if you decide you want more grip, they have a fairly long wear life for an R-tire