Tires: Rotating weight vs radial construction

[Bobby Fazio]

Would you rather run a 30lb radial or a 20lb bias ply? My problem is no one makes a drag radial less than 30" and I can't fit a 30" tire under my 5.0. I am either forced to use a heavier 275/60/15 street radial tire with a questionable tread width of 8.5-9.5" or use a lightweight bias ply 28x9 slick. Are radials worth as much ET as everyone says?

Does NHRA have a ruling on 275/60/15 in stock eliminator? I would really like to use the new Goodyear 4305 but different websites advertise different tread width for it. Neither the Hoosier or Goodyear trucks had any DOT radials at zmax so we couldn't measure.

[Eric Merryfield]

Originally Posted by SStock1373

Would you rather run a 30lb radial or a 20lb bias ply? My problem is no one makes a drag radial less than 30" and I can't fit a 30" tire under my 5.0. I am either forced to use a heavier 275/60/15 street radial tire with a questionable tread width of 8.5-9.5" or use a lightweight bias ply 28x9 slick. Are radials worth as much ET as everyone says?

Does NHRA have a ruling on 275/60/15 in stock eliminator? I would really like to use the new Goodyear 4305 but different websites advertise different tread width for it. Neither the Hoosier or Goodyear trucks had any DOT radials at zmax so we couldn't measure.

Bobby try the hoosier dot radial they are really lightweight for a DOT tire..24lbs which is close to the weight of a 30 inch drag radial..but you will have to do with the 28 inch diameter

If you can fit a 295-65-15 you will get 29.6 od, for 27 pounds..The MT et drag radials are the 38 pounders, but they are a very stout tire, were/are the choice for the super fast outlaw type cars, but they are 30 inch tires.

I think the critical question for you is are you going to running a stick? If so the radial might work or not, with a low HP pure stock style Stang.

On a non tire question......how do you block just the middle bulb?

Eric

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[Bobby Fazio]

Eric, the hoosier dot radial was my other choice but it is a 10" tread width according to their website and jegs/summit sites so I don't know if its legal in stock eliminator. I am using an 8" rim so I don't know if that would bring it down to legal tread width.

[Chris Hill]

Gut says lower rolling resistance of radial will be faster than lower rotational inertia of bias ply tire.

Rotational inertia is more a factor the faster it spins and axle/tire wheel combo is very low speed relatively speaking. Axle rpm though traps will be in 1,500 rpm range for a stocker.

Figure the stick guys would chime in here. Similar to a heavy vs. light flywheel debate and I don't have a dog in that fight.

[tj310]

Rotating weight is not the same as flywheel weight . A heavy flywheel may help launch. Heavier rotating weight ( wheels tires brakes axles ) is just extra weight to accelerate. Depending on who's formula you believe tire weight is about 3 times as important as dead weight. ---Trevor

[Todd Geisler]

You need to find out if a 275/60 D/R is legal for Stock or not.

If so, the Hoosier is a very good choice. For the past couple years it has been the tire of choice for X275 racers running as quick as 4.70's in the 1/8 mile with 60's in the mid teen range, so it's a proven performer. The Hoosier weighs 24 lbs each.

Mickey Thompson came out with a tire to compete with the Hoosier which it's new part number is 3754X. Not fully released right now and again, need to verify legality for the stock class. The new M/T weighs 32 lbs each.

Rumor has it Hoosier wasn't happy with M/T coming out with it's new "Pro" 275 and is planning a tire to compete with it. Should be interesting to see if and how this plays out.

If legal, put them on a 10" rim.

[Bobby Fazio]

Originally Posted by Todd Geisler

You need to find out if a 275/60 D/R is legal for Stock or not.

That is what I've been trying to find out. I can't fit anything larger than a 28" tire under the car so my only option is 275/60/15 street radial or 28x9 bias ply.

[Jeff Kempton]

From the NHRA 2012 Rulebook:

"Section 10A, page 9 Stock Cars

TIRES
Street-type or drag slick tires, maximum 9-inch tread width. Tires
may not be altered from tire manufacturer’s original design or
pattern. Size of tire (new) must not exceed 9-inch wide x 30-inch
diameter (94-inch circumference). Tires may not exceed 10 inches
wide regardless of wear. Front tires must have a full street pattern
and must measure a minimum of 4 1/2 inches on ground. Tire tread
may not extend outside fender; maximum clearance between side
wall and body is 3 inches. Slicks permitted on FWD cars. All-wheeldrive
vehicles must have treaded front tires. Recapped/retreaded
tires prohibited. See General Regulations 5:1."

[partsbob67]

a lot of mustang guys running the 30" hoosier out here. why won't yours fit? mine hit on the back side, just had to trim them on the back side a little.

[ALMACK]

Originally Posted by Jeff Kempton

From the NHRA 2012 Rulebook:

"Section 10A, page 9 Stock Cars

TIRES
Street-type or drag slick tires, maximum 9-inch tread width. Tires
may not be altered from tire manufacturer’s original design or
pattern. Size of tire (new) must not exceed 9-inch wide x 30-inch
diameter (94-inch circumference). Tires may not exceed 10 inches
wide regardless of wear. Front tires must have a full street pattern
and must measure a minimum of 4 1/2 inches on ground. Tire tread
may not extend outside fender; maximum clearance between side
wall and body is 3 inches. Slicks permitted on FWD cars. All-wheeldrive
vehicles must have treaded front tires. Recapped/retreaded
tires prohibited. See General Regulations 5:1."

2 year thread revival because I am curious if anyone has tried to get a 275-60-15 tire size to pass tech in Stock ?

I am looking into running a drag radial on my T-Bird for combo races and Divisional events.

The rulebook says " Tires may not exceed 10 inches wide regardless of wear "

Is that 10" of tread pattern or 10 inches of contact patch ?