i know if you swap gears or change tire sizes it will mess up your speedometer but is there anything wrong with running taller tires on the street and putting smaller ones for the track? the reason would be for the (simulated) extra gearing. i seem to remember hearing something about the car not shifting right or something. so would there be anything wrong with this or should i give it a try?

 

It would upset your shift points to some degree. If you're talking about a 1/4", I don't think it's a big deal.

I used to run 26" E/T's at the track and 25.75" Nittos on the street. I just set my PCM up for the track as that's where I wanted to be totally accurate.

Mark

 

do you now off the top of your head if smaller tires would make it shift earlier or later?