1/4 mile E.T and tire size

[darren509]

Going back to the track on 9-21 and want to take off my rear rims and tires which are 15x8 , 275\60\15 and put on a 245\50\15 on the rear to pick up a little on the times. That set up will be on the rear so my question, is it o.k to have a smaller tire on the rear just for a few passes ? My gear ratio is 323 so thats why Im asking

[DartGT66]

What are you after with that mod? A better launch? If your tires do not spin with the current tires, then it might help. If yo already have too little traction, they will propably not help. The stiffer sidewalls of the 50 series will propably provide worse acceleration traction. But it's hard to say without trying. One solution is to get an other set of wheels, some 14 inchers with around 205 tires, 70 or 75 series. I think they should be shorter, an dyou might be surprised about the results. BTW, I run 11.609 two weeks ago with 3.23's and 205/70/15 KellyNavigatotrs!

[sixpackgut]

useing the shorter tire will help make your car quicker and i not sure the tread with on the new tires but a 275/50/15 would be an inch wider than what you were useing.

[darren509]

My car is a 318 and ran a 16:01 so traction was not an issue. I would just like to cut off a few tenth's here and there. Ive always been told that a smaller tire is like making a small change in ratio. I only will be doing this on the passes because the wheels and tires are allready ready from another car

[darren509]

I made a mistake on first post, I would be taking off the 275 and putting on a 225.

[jelsr]

As long as you are not mixing bias ply's and radials it is not a problem. 1" in dia will make slightly over 3" in circumference so going smaller (dia) will have the same effect as lower (higher numerically) gears.

[dave571]

Keeping a taller tire on the front, will also help your weight transfer.

I run the truck and the van, with taller tires on the front than on the back, while racing.

[darren509]

Thanks guys !!