Years again, I penned an article titled Professional Suggestions for Tire Strain that talked about setting drag race tire pressures and coping with altering circumstances. It supplied a variety of good recommendation, nevertheless it dealt largely with slicks.
However when you’re into the street-legal and drag-and-drive occasions which have turn out to be so well-liked, you’re working DOT-legal drag radial tires. These are a complete completely different animal than slicks. In case you’re fortunate you may have a spare set of DOT drag rubber mounted on wheels. If not, you’re coping with the tires you drove to the observe on. That’s why I wrote this text.
Establishing a Baseline
It is perhaps stunning to find that typical DOT avenue tires truly like extra stress than regular in a drag race utility. However, a sticky drag radial would possibly like far much less stress than you may need thought of. There’s one other catch—some drag radials are designed to work at decrease pressures than others. In consequence, you possibly can’t simply set your tire stress to the identical PSI your buddy makes use of along with his Mickey Thompsons, M&H Racemasters, Nittos, or Hoosiers.
The width of wheel you utilize can have an impact upon the tire stress. So can the observe prep. Some have higher prep than others. Some haven’t any prep. A closely prepped observe has a shiny floor—it nearly appears to be like moist. A observe that isn’t prepped can have a floor that appears boring.
All this implies it’s a must to set up a baseline tire stress. The primary order of enterprise is figuring out how a lot of the tire truly contacts the pavement. You don’t must be on the observe for this. Merely drive via a little bit of water on pavement and look at the contact patch. It’s best to be capable of see if the middle of the tire is making extra contact than the perimeters. If that’s the case, there’s most probably an excessive amount of air within the tire. If the outer edges present extra contact space than the middle, the tire wants extra air. Setting tire stress this manner is not any assure that it’s the precise stress in your automotive, nevertheless it’s a place to begin.
Listed here are some fundamental stress suggestions from M&H Racemaster and Mickey Thompson:
• Tires beneath 30 inches in diameter: 12-16 PSI
• Tires over 30 inches in diameter: 11-14 PSI
Mickey Thompson ET Avenue R Drag Radials
• Minimal stress: 11 PSI
• Tires as much as P275-50R15: 12-16 PSI
• Tires P295 and up: 11-14 PSI
With most drag radials you’ll in all probability wish to begin at 20 PSI and work down from there. You probably have a stick-shift automotive, you could have to set the stress a wee bit larger. You’ll additionally must work laborious on clutch manipulation as handbook transmission vehicles appear to love bias-ply tires higher.
Now it’s time to go to the observe for some apply runs. After you’ve made a number of passes, test the damage throughout the tire face. You need the tire to put on equally throughout the whole width. Once more, an excessive amount of stress leads to heavier put on within the heart, and too little stress leads to heavier put on on the outer edges.
After you have equal put on throughout the face, you may have the baseline tire stress that your automotive and tire mixture like. Be certain to put in writing this quantity down someplace. You may need to regulate tire stress to compensate for climate and observe modifications, nevertheless it’s far simpler when you solely have to change it barely moderately than ranging from scratch.
Clearly, you’ll want a tire gauge to determine a baseline stress and make any mandatory modifications. A standard pencil gauge gained’t lower it for the low pressures you’re coping with. Spend the cash to get high quality analog dial or digital gauge—there are a lot to select from.
Attempt to use the identical gauge each time you test or change air stress. Readings do fluctuate between gauges. That’s why many professional racers all the time use the identical gauge and report the pressures in a log ebook.
Different Concerns
What about burnouts? The kind of burnout you carry out is expounded to your tires’ compound. M&H gives this recommendation when utilizing its HB11 compound drag radials:
“A tough burnout isn’t mandatory. For the primary move of the day, make a lightweight to average burnout. After that, a lightweight burnout ought to suffice. Proceed the burnout till the engine begins to drag down. A dry hop after the burnout isn’t beneficial. For a stick-shift automotive, carry out a lightweight burnout, haze the tires, and stage instantly.”
Mickey Thompson says the tread compound used for its ET Avenue Radials is designed to warmth rapidly and doesn’t require a heavy burnout. A dry hop after the burnout isn’t beneficial, both.
When within the pits or ready within the staging lanes in the course of the day, needless to say the solar can play havoc with the tire stress, notably on the facet of the automotive that faces it. That’s why professional racers usually cowl their tires whereas ready. Summit Racing gives a number of sorts.
The preferred (and customary) is a lightweight coloured cowl that attaches with suction cups. The colour higher displays the solar’s rays and the suction cups permit attaching the quilt to steel and composite fenders. You probably have a problem with making the suction cups stick, strive utilizing lubing them with a twig bottle stuffed with a number of drops of dish cleaning soap or automotive wash cleaning soap. Usually cleansing the suction cups with rubbing alcohol is a good suggestion too. It really works for me.
Probably you’ll be driving your automotive to the observe as an alternative of trailering it. Which means you possibly can’t haul a big air compressor with you to regulate tire stress. There are a few choices. First is a transportable air tank. Summit Racing has them in capacities from 1.5 to twenty gallons in metal and aluminum. A transportable tire inflator is another. Most run off 12 volts out of your automotive or tow car battery, however there are some that use rechargeable batteries. Some take 4 or 5 minutes to inflate a tire from flat to 30 PSI. Because you’ll be adjusting stress in fairly small increments, you shouldn’t have any main points.
One of the best thought could also be to take the guidelines we offered right here and a few from the Professional Suggestions article and create a tire stress ‘program’ that works finest for you. Simply do not forget that each automotive is completely different and can want its personal stress tuneup. And please, don’t neglect to make use of a logbook!
