Do any of you guys run different size tires on the street then on the track?

I was thinking about doing it so not to wear out the ET Streets I am going to get soon. But I am not sure what might happen if I get it tuned for the taller tires for the track and run shorter on the street and so forth...

Or would it just be easier since I have the performance shift button to change my shift points for the taller tires only when that button is pushed???

 

The size of your tires shouldn't affect anything in the programming except for speedometer/odometer calibration. Get it tuned based on your street tire size, set your shift points however you want them (and leave them that way for street and track), and be aware that your speedo may be wrong at the track.

 

he has an A4... shifting is not RPM based, but MPH based... so, his shift points will be messed up if he doesnt account for the size change.

 

This was my thought, but in looking into the tables I think I am just going to set it up for street tires for the constants yet adjust the shiftpoints when the performance shift button is selected to where they would do the best for the taller tires at the track... I just have to figure them out and that will be a lot of T&T's...

 

Use this web site, it will get you a ballpark figure that will be pretty close.

http://www.f-body.org/gears

 

LOL, that's just funny and I will let you guess why...

 

Oooh, I have a guess.

On an entirely unrelated note, that's a nice sig you have there.

 

Thanks...

 

care to enlighten me?

 

The site with the calculator you posted appears to have ripped it off from the calculator on his site, which is linked in his signature.

 

Lol, didn't notice that.

I've seen that link passed all over the place, never knew it was ripped from somewhere else.

 

No they won't. If you don't touch the programming, the shift occurs at the same RPM as before.

 

Actually both parameters (MPH & RPM) need to be met for the computer to comand the shift...

 

And if you don't touch the programming, both parameters (MPH and RPM) will be met at the exact same RPM as before.

 

NO WAY... If you change tire size and have it programmed for a different tire the MPH read by the computer will be off...