Im unsure on how does running wider tires affect the MPH at the drag strip. Give me some input guys. Im running 255/40/17 size tires.

 

No. Your tires are now smaller than stock which is a circumference problem, not a width problem.

 

smaller means slower?

 

So a smaller tire would show lower traps?

 

Wider tires will not affect your MPH in the way that the circumference of the tire will. Depending on what brand/type of tire you may get better/worse traction I guess... but width shouldn't affect MPH other than maybe getting a better launch, etc...

 

Smaller circumference will make acceleration faster... but may have you running out of gear and needing to add another shift.

 

Like he said Width will not effect your trap speed other then more rubber on the road for traction. Its the size of the wheel wall you need to worry about and rim size. The Smaller the wall size or rim the more rotations you need to go so far, so more Tq and the bigger the tire the higher the trap speed.

 

so is my trap about right for my power output? Trap of 113

 

I would say its about right. All depends

 

What im getting at is. I ran a 12.1 @ 113mph with a 1.81 60ft shifting at 7500rpm. Car weighed 3360lb that day. Say if i would have shifted higher and got the 60ft down to say 1.6 how much faster would my time be. I know theres alot of variables.

 

bump

 

wider tires have more aerodynamic drag... more frontal area...

cb

 

Wider tires will effect trap speed since there is more rolling resistance. This is exactly why the FWD cars run skinnies in the rear and RWD cars run skinnies up front.


Even running less tire pressure effects trap speeds since it too increases rolling resistance.

 

so how much mph would it take off the trap speed? estimate?

 

Wider tires will affect performance less than the tire pressure being used.