Tire size effect on 1/4mi. times

[Lonnie]

Does anyone have a comparison of different size tires & their effects on 1/4 mile ET's? I'm wrestling with a tire decision for my truck & wondered if anyone had proof of how much a larger tire slowed your truck down. I will probably go with 33" tires, but going fast is still important. Just trying to see how much I have to alter my decision.
Thanks in advance.
Lonnie

 

[McRat]

Depends on how much power.

Factory 30" tires are great on a prepped track with up to 500rwhp.

After that, you will need more traction. Taller tires do two things:

More footprint
Less applied torque

But more weight, and higher wind profile on the truck.

We have run tires from 28" to 33" tall on Casper and Blue. Big tires do not hurt like they do on cars. ET's have been awful similiar. Some of our best runs have been with bigger tires.

 

[SBCNX20]

I wonder now with the skip shift eliminate and a shorter tire could be a good combo.

hmmm

 

[05_LLY]

My findings have been the same as Pats other than i find the truck launches better for me with a smaller tire (around 29 inches) than it dose with a 32inch or so tire, but that the down fall of racing a stick truck! My tire choce for this year is Toyo ST 285/60/17s they measure right @ 30" tall and a pinch over 9" TREAD width mounted on H2 wheels!

 

[chevmike]

When my truck was basically stock ( so tire spin wasnt an issue) i ran better with a 33" then I did with the stock 245's. Has to do with they turn more revolutions once they get rolling. I have also been looking at running a 20" wheels but there is also the discussion of weight. From what I see though there really isnt a difference in weight more then a few lb's running them. I would think the added traction would make up for 2 or 3 lb's. Ill experiment this summer.

 

[Lonnie]

Thanks for the info.

The truck is my '82 conversion, probably 5800lb max.
McRat LLY 500RWHP tune.

I was curious based on my experience with my other truck (gas engine). Went from 32's to 35's & it felt like it lost 100hp. Even after changing gears to get the equivalent ratio back, it still was much slower.

Pat like you said about cars, I lost .1 sec & 2mph going from a 26x11.50 to a 27x11.50 tire on a low 12 sec Camaro... even though the 60' was a few hundredths better.

So what is the difference from say a stock tire (245) to a 285 or 33? Is it 1/2 sec or ?????