front tire size worth in delay
 

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?

Re: front tire size worth in delay
 

All else being equal, they should be worth.....something.
Sorry for the nonspecific answer, but the question is that way ,too.
BTW, if you're on a pro tree, shouldn't you be over on the .90's forum?

Re: front tire size worth in delay
 

bottom bulb full tree I know a larger tire will help slow down reaction time, added roll out i was hoping others have tried different tire sizes and found out what size is worth what

Re: front tire size worth in delay
 

Worked for me.... dad needs to do the same thing right now... @ the local 1/8 mile track he only runs 18psi in the fronts (26")

Re: front tire size worth in delay
 

Lower the RPM

Re: front tire size worth in delay
 

I'm a little confused (not an uncommon state) but why would a tall tire slow reaction time?

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

Not a slam against you electronic guys.

Re: front tire size worth in delay
 

Mark,
Why would you think he is a .90 racer. Even if he is what difference should it make the driver has a problem.

913,
I think the tire will help but not very much. The problem you will run into is it may help a race or two, then you will get comfortable and start going red again. I bottom bulbed for over 20 years. When the Led's came out it screwed me up. I fought it for 5 years. I built 3 different cars. Different e.t. range. The problem always came back. I won a lot of races and finished high in the points too, but the problem always came back. Not saying I gave up but I moved on. I found a home in Delay Box/.90 racing for now. I may come back one day, but will have to build a "BETTER MOUSE TRAP"
Some things we tried on the last 2 cars.
Tires-front and rear
RPM
Blocking
Timing
Rear Gears
Transmissions
Trans gear ratios
Convertors(Lots of them)
Headers
Header collectors
Traction bars
Weight (LOTS OF IT)
Weight in different locations
Mufflers
DeTune the motor which worked somewhat but did effect consistancy and then when you get a heads up you are out to lunch.
De Tune- with Cam Timing, different oil, More oil, We ran a holley and tried it on 2 bbl. etc, etc, etc,

We were trying to kill the initial move of the car but keep it fast and consistent.

Good Luck.
Chip Johnson

Re: front tire size worth in delay
 

Experiment with lowering air pressure in front tires, lowering rpm a little at time.

Re: front tire size worth in delay
 

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

Re: front tire size worth in delay
 

[QUOTE=THE LEGEND;131331]Mark,

Why would you think he is a .90 racer. Even if he is what difference should it make the driver has a problem.

Chip, because he said he said he was ABLE to go red. That sounded like .90 talk.
Anybody can go red on a full tree.
Nothing personal. Just trying to get him in the right place.

I know what you mean about the LED lights. I wasn't "the driver " when they first came out.
Then I built a car with an adjustable button. I was trying to get away from deep staging with the autostart. I'd adjust the button and then end up right back where I was , usually red. No real explanation for it.
I've since gone back to deep staging and a solenoid to set the rpm at the last second. I seem to be on the right track with that.

Re: front tire size worth in delay
 

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.

Re: front tire size worth in delay
 

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

Re: front tire size worth in delay
 

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

Re: front tire size worth in delay
 

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.

Re: front tire size worth in delay
 

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

Re: front tire size worth in delay
 

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.

Re: front tire size worth in delay
 

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.

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/

Re: front tire size worth in delay
 

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

Re: front tire size worth in delay
 

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.

Re: front tire size worth in delay
 

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.

Re: front tire size worth in delay
 

Yes, I forgot to add SS racers to the mix, my point is that "footbrake" racers work harder on their packages than electronics guys and most of the stockers and some SS'ers run tall tires. I run 29" moroso's and when in practice I have run O's and OO"s with them, so how does a tall tire hurt me vs a small tire?

Jim R

Re: front tire size worth in delay
 

I run the tallest I can get under mine. I have had several 00s, if your over .030 in SS at a div race around here your usually going home. Too many Emmons, Cumings, Helms, etc. I can't seem to get off Slate's side of the ladder. That kid kills the tree.

Re: front tire size worth in delay
 

Lay a board in front of the tire and one behind it at say, 30 psi. Measure the distance between them. Lower air to 22 psi and do it again with boards. THat is change in physical roll out.
Go to the pits and ask some guys if you can measure that same thing on some different tires.

If I was looking for a solid .01 (which I was with Camaro) I would look for 1" to 1.5" wider gap in the boards. I went from tall Moroso to 26.5 M/T and it was about 1.5" at 26 psi. Haven't been red since but then again....I have been late a few times.

I still feel it is best to find a "spot" you like to leave at and you are consistent at, then work on the car to use that "spot".

A lot of guys on here have done this more than me but we are getting better every time out. I just keep running into guys who crush a .006 light and run the number...I know my day is coming, just have to keep working on it.

Good luck in your tire search.

Jok

Re: front tire size worth in delay
 

Thank you for your help

Re: front tire size worth in delay
 

careful there 442 darryl...i believe you are touching on performance enhancing drugs...

jack

dont forget the ET difference them big tires help with :)

Re: front tire size worth in delay
 

I'm with Mark on this one.... but I am OL' SKOOL also.... drop RPM.... and/or drop tire pressure.... but as stated earlier, it will probably be a race to race thing as you get used to your changes.... I used to have a good crew guy who would make the changes without me knowing, and I would just do my normal thing.... worked great until I finally gave in to electronics.....

Re: front tire size worth in delay
 

" still feel it is best to find a "spot" you like to leave at and you are consistent at, then work on the car to use that "spot"."

I agree wit this 100 percent L.E.D.s caused me to sell my Duster after 17yrs Used to footbrake with 13" front tires on the old bulbs.440 Dusters with fenderwell headers have major tire clearance issues and chassis headers will really slow them down and cause other issues. I had a new set of Hooker S/C,s (over $500) modified (another 300) to get a taller front tire.Still could only get 25" Still red lighting unless I sit on the bottom bulb.Then I was just terrible. I could have fixed it with a glide I guess at even more expense.I came on here and you guys helped all you could.-----heres how I addressed the problem--with a 81 Malibu wagon! Had to fix the motor and come up with some parts but its about 2-3 tenths away I look forward to the day I can slide the 28" tire on there if needed.