Motorsport News

How to find the ideal wheel and tire size for your track car | Articles

How to find the ideal wheel and tire size for your track car | Articles

How do you determine the ideal wheel-and-tire setup for your car? Sometimes you need to do a little testing.

As we prepped for this year’s One Lap of America, we needed to make one key decision as early as possible: What tires should we run on our Honda CRX

Miata Tire Test Times

But every tire is different, and the A052 is typically not happy being pinched. Of course, with the available A052 tire sizes for our CRX, pinching was not going to be a factor. In fact, the 205s were fairly stretched on 9-inch-wide wheels, with the 215s and 225s being a normal straight-up fit.

CRX Tire and Wheel Specs

Now to see which tires our CRX preferred. One logistical shortcut we took was to change only the front tires for each round of testing–the rears were kept constant at 205/50R15. 

With our nose-heavy, front-drive application, the fronts do most of the work anyway, so this shortcut has served us well in the past. It did make for some rather odd-looking combinations, though. 

From left to right: 205/40R17, 215/40R17, 225/50R15, 205/50R15

As we always do, we heat-cycled our tires prior to test day. In this instance, the entire operation was done at the track. We built heat into them by doing some skidpad circles in an empty paddock area before running six laps on each set of tires. Tires were then removed and allowed to cool for 24 hours, better curing the rubber for optimal performance.

Not all tests go as planned. We typically do our work on weekday mornings when the track is mostly empty. This minimizes track evolution beyond an initial dust-off, and also allows for uninterrupted lapping for evaluating heat-sensitive tires. But this weekday was different, as a slew of cars began to fill the paddock not long after the track opened. Still, we were hopeful we could find gaps in the flow to make it work.

  • size: 205/50R15 
  • best lap: 1:24.3

After 20 minutes of lapping on some old scrubs to clean the line and get our shifting and braking points dialed in, we mounted up the 205/50R15s to set our baselines. With the A052 at full tread, the first lap is typically the quickest. Heat soak sets in soon after, dropping the performance potential. 

  • size: 205/40R17
  • best lap: 1:23.9

Our next size was a little wider but also had much…

Click Here to Read the Full Original Article at Grassroots Motorsports Online Articles…