front tire size worth in delay

[Jerry Hatch]

Originally Posted by racer913

I have ben having a problem with being able to go red I need to know what tire size is worth in roll out delay I have 26" tires on and I need about .010 would a 28" tire work?

racer913,

Depending on what you have for a car, a two inch taller tire may be exactly what you are looking for in reaction time gains (or in your case, loss). I bracket raced a ’65 Dodge Coronet 500 2 dr. hardtop for nearly 14 years with the same combination. It was making approximately 425hp, ran 7.50’s 1/8th and 11.90’s in the ¼ with 1.55-1.58 60 ft depending on the track and conditions. I was not happy with my reaction times with a 26” tire in the beginning and went to the taller 28” tire. After doing so, I lost approximately .010 - .015 in reaction times. My car weighted nearly 3600#. Keep in mind that air quality plays a substantial role in how quick a car of this weight and hp moves off the line. Lighter quicker cars will not see the same loss in reaction times as a heavier car with this same tire change. Jerry.

[tpoh815]

Jerry sounds about right .Chip holy cow, easy on the knowledge. Thats 20 years in 2 min!

[442OLDS]

If you are redlighting,try taking a couple of aspirin.If your lights are slow,drink a few bottles of Mountain Dew!

[treessavoy]

Originally Posted by SmallBlockNova

You get a longer "run" at the beam before you knock the stage light out and start the clocks..

True you get a longer run but the roll out distance is the same, the taller the tire the sooner you can leave on the tree.

Small tire, big tire you still have to roll that 9 inches to break the beam.

[Jim Wahl]

Originally Posted by 442OLDS

If you are redlighting,try taking a couple of aspirin.If your lights are slow,drink a few bottles of Mountain Dew!

This is funny! I don't care who you are! Jim

[SmallBlockNova]

Originally Posted by treessavoy

True you get a longer run but the roll out distance is the same, the taller the tire the sooner you can leave on the tree.

Small tire, big tire you still have to roll that 9 inches to break the beam.

The taller tire is able to move more distance before the beam is broken, thus resulting in quicker ET's yet slower RT's. Think about it...There's still 6 inches between the stage beams. If you take a tire that is 26" in diameter and center it on those beams, then roll it and write down the distance it rolled before the beam was broken...Then do the same with a 28" tire...The 28" tire will roll more distance before it breaks the beam.

[Michael Beard]

Hatch is correct. Given 'typical' and equivalent tire pressures, a 2" diameter change will probably net you .010-.015. I went the other way a number of years ago, trying to deal with the very loose rollout at Quaker City. I went from a 25-26" tall street type tire to a 23" frontrunner, and was surprised to find that I only gained about .015 in r/t.

Originally Posted by treessavoy

True you get a longer run but the roll out distance is the same, the taller the tire the sooner you can leave on the tree.

Small tire, big tire you still have to roll that 9 inches to break the beam.

What you are saying is only applicable if you're deep-staging, in which case you have part of the tire *in front of* of the stage beam, with the remainder being between the stage and pre-stage beams. In regular staging, the 'extra' tire is still *behind* the pre-stage beam, and that too needs to clear the stage beam to stop the r/t clock.

Much of this is discussed in my Guide to Bracket Racing, at www.staginglight.com/guide/

[novanicks]

In my experience, you will get exactly what you need in changing the tire. I would even suggest that it would be worth .010 and up to .020. Just make sure that if it makes you too slow that you have a way to add some reaction time back if needed.

Nick Shepherd

[Ed Wright]

Originally Posted by treessavoy

Stock drivers are known for the quickest and consistent reaction times and most of us run tall tires.

Really?? First time I've heard or read this. The only National Dragster I have on hand right now has E-Town sportsman coverage. I averaged the Comp, SS and Stock elimination round reaction times. Comp had 8 red lights, average reaction time was .0675. (Wonder why Fletch and Biondo do so well there.) SS had 4 red, average reaction time was .0335, Stock had 3 red, average was .0448. The .90 classes, of course, killed us all. Should with all the crap they have on those cars. I can't see why foot brakers would have any advantage, from what I have seen S & SS are normally pretty close in that dept.

[Michael Beard]

Originally Posted by novanicks

In my experience, you will get exactly what you need in changing the tire. I would even suggest that it would be worth .010 and up to .020. Just make sure that if it makes you too slow that you have a way to add some reaction time back if needed.

On the plus side, changes in rollout will effect your reaction time far more than it will your E.T.'s At some loose rollout tracks, I've taken 2 bumps after staging to pick up .015 in r/t, but only loose a few thou in 60' & E.T. IMO, it's a good tradeoff.