Tall fry tires vs. Short front tires

[Mike Gaines]

Let's hear it on the pros and cons of running tall front tires versus short front tires. Personally I have the old school Moroso 760 by 15 really tall front tires. Many guys run the really short front tires like 25 or 26 inch tall. Tell me the advantages of each or disadvantages of each. Thanks let's hear it

 

[Dibbons]

On my Valiant, I used a 165/80R15 which is a 25.4" diameter '70's VW Beetle (standard size) tire which I used on narrow Centerline rims. Don't know why, but back in the '70's bracket racing days, I was told to run these.

 

[bobtile]

Let's hear it on the pros and cons of running tall front tires versus short front tires. Personally I have the old school Moroso 760 by 15 really tall front tires. Many guys run the really short front tires like 25 or 26 inch tall. Tell me the advantages of each or disadvantages of each. Thanks let's hear it

I got what you got.
Thats all I know.

 

[mmissile]

I don't drive well enough to notice....but guys claim it effects R/T.

 

[Cornpatch MO]

My theory--a large diameter leaves a tire in the " beam" for a longer period of time. That would allow you to leave a little earlier, while you were still in the beam = no red light. ??...................MO

 

[dvw]

Your car on a .400 tree needs the shortest tire possible. Needs the least roll out for a heavy car with lots of suspension travel. A 24" is pretty ugly though.
Doug

 

[mmissile]

My theory--a large diameter leaves a tire in the " beam" for a longer period of time. That would allow you to leave a little earlier, while you were still in the beam = no red light. ??...................MO

That's old-school. Doug has posted the current thought-process.

 

[dvw]

My theory--a large diameter leaves a tire in the " beam" for a longer period of time. That would allow you to leave a little earlier, while you were still in the beam = no red light. ??...................MO

Your analysis of the tall tire is correct. Takes longer to come out of the beams. For me a 28.5" works well with a .500 tree. But with a .400 pro tree tree it would put you .100 behind. So either a shorter tire, deeper stage, or quicker reacting car.
Doug

 

[Mike Gaines]

Your analysis of the tall tire is correct. Takes longer to come out of the beams. For me a 28.5" works well with a .500 tree. But with a .400 pro tree tree it would put you .100 behind. So either a shorter tire, deeper stage, or quicker reacting car.
Doug

If both the tall and short frt tire starts the et clock at the same time ( which they would) how could the height of the frt tire effect your et. (Take the reaction time out of the equation ) in other words if 2 cars (1 with short tire and 1 with tall tire) leaves the start line at the SAME TIME and neither one redlites how could the reaction time measurement come into play ? I need help with this logic.....

 

[dvw]

It is correct, they both start the ET clock at the same time. However it takes the larger tire longer to come through the beams. It has more circumference. Therefore two things will happen, if the runs were otherwise identical. #1 the shorter tire will give a quicker reaction time as the car actually travelled less distance from being staged until it broke the start beam. #2 the ET will be sightly slower due to the fact with the taller tire the car had a longer run at the start beam.
Doug

 

[theman440]

I like a taller tire because it's one more way you can adjust your reaction time buy how deep (or shallow) you stage.

 

[Wookie316]

I like tall tires because Barney would look goofy with a 26 or lower tire in the front. He’s too big.

 

[1967coronet440]

Got a 26” on mine with a 17x4.5 wheel, looks good but no performance data to share yet might end up going bigger.

 

[Mike Gaines]

It is correct, they both start the ET clock at the same time. However it takes the larger tire longer to come through the beams. It has more circumference. Therefore two things will happen, if the runs were otherwise identical. #1 the shorter tire will give a quicker reaction time as the car actually travelled less distance from being staged until it broke the start beam. #2 the ET will be sightly slower due to the fact with the taller tire the car had a longer run at the start beam.
Doug

WITH A .400 PRO TREE IS A SHORT TIRE OR TALL TIRE BETTER to win the race ??.
I cannot redlite with a .400 pro tree. Tall tire is no advantage in that respect....

 

[Cornpatch MO]

That's old-school. Doug has posted the current thought-process.

Yup, old school--that's me. DVW post after yours, teaches me some new school... I can see why flag start is getting so popular with us old foggey's .................................MO

 

[dvw]

WITH A .400 PRO TREE IS A SHORT TIRE OR TALL TIRE BETTER to win the race ??.
I cannot redlite with a .400 pro tree. Tall tire is no advantage in that respect....

Can you deep stage? That will help more than anything. But to answer your question you need the shortest tire you can get.
Doug

 

[Mike Gaines]

Can you deep stage? That will help more than anything. But to answer your question you need the shortest tire you can get.
Doug

thanks doug, I now believe in the short tire for the pro tree.

 

[Frustration]

If both the tall and short frt tire starts the et clock at the same time ( which they would) how could the height of the frt tire effect your et. (Take the reaction time out of the equation ) in other words if 2 cars (1 with short tire and 1 with tall tire) leaves the start line at the SAME TIME and neither one redlites how could the reaction time measurement come into play ? I need help with this logic.....

Mike, They won't both start the clock at the same time. Think of the beam going across the track as a laser. You pull into the stage beam and the stage light goes on when you break the laser beam. The beam won't be complete again (starting the race) until the mass of the tire passes through the beam. Think of the rear of the tire more than the front of the tire. The timer won't start until the entire tire passes through.

That being said, I LOVE 28-29" tall tires on B-Bodies! They just look right. Doug's advice about deep staging will allow you to keep your awesome Morosso's and still cut a good light.

 

[Mike Gaines]

Doesn't the ET Clock start when the BOTTOM lite turns GREEN, regardless of when you actually launch and get your Reaction Time off the rear of the front tires letting that beam connect after you start moving to get the time it took you to move AFTER the ET GREEN LITE CAME ON ?

 

[Mike Gaines]

And.....with a .400 pro tree the only real purpose of the rear beam connecting is to NOT have it connect until the bottom GREEN BULB come's on ??? As long as you leave quickly and at the same time as the other guy (if you both were dialed in at, let's say, 10.20) would the the taller tire have a slower reaction time than the other guy who might have a 25" frt tire..
But then that reaction time would be meaningless as long as both cars actually moved at the same time ????