Racing size tires

[dnrnflcpl469]

We have a 73 Nova with a big block 402. It has a 3 speed automatic ratchet shift transmission, 3400 stall converter current tire size 28x14xr50 i have been told and have not been able to confirm that we have 411 gears and also been told we have 373 gears the car is extremely torquey pushing 450 hp after depending on which gears i have what tire size does everyone recommend for racing slicks? Also should i tub the tires or cut the fenders out and leave the axle alone, my current 14" tires stick out approximately 3" on either side of the car.. Is there any advantage to tubbing the wheels? Please advise.

[LowETz]

IMHO.... a 28" tire is a little much for a 3.73 gear in an automatic unless you're planning on hosing it, or are making some killer rwhp #'s. What are you trapping, and at what RPM? Where does peak power fall? Is that 450hp @ the crank or the wheels? Where's the limiter at? Where are your current best 60' #'s?

Lot'sa folks fall into that "bigger is better" trap when it comes to tires, and there are a LOT of guys running too much tire for the combo, and inadvertently hurting their #'s.
The thought process being the bigger the tire, the better the hook > 60'. Not always, and very rarely true. The determining factors(above)need to be considered before you can make the correct choice.

Take a look at what some of the NMCA/NMRA guys are running for tires. They're getting some insane #'s on true 10" tires(26"/28" drag RADIALS).

I'd be willing to bet that w/a smaller tire(say... 26-11.50-15 ET DRAG), with the power you're making on a 3.73 gear(if that indeed is the gear you're running)would result in a lower 60'/ET, though trap speed will suffer a touch. For every .010 you cut from your 60', you'll drop ~ .015 off your ET. Conversely, a taller tire on the same gear will raise your 60'/ET #'s, though MPH "should" rise. Kind of a trade off of sorts until you're making big # power. If in reality you're on a 4.10, a 28" tire would be better suited for your stall/power.... (IMO).

FWIW.... I switched up last year from a 26" ET Street on a 4.10, to a 28" ET Street on a 4.56. The taller tire is 60' ing better and easier to get down the track than the 26", but b/c I also went lower(numericaly higher)on the gear, I've cut my 60'/ET, AND picked up MPH because the gear ratio vs. tire height was a wash..... basically turning the same RPM's through the traps as the old combo.

As far as narrowing/tubbing.....AFAIC.... unless you are deflecting axle tubes at launch, or twisting/breaking axles(which I'm assuming is not an issue at 450hp), I wouldn't bother. What I "would" do is replace your rear wheels w/the correct BS(back spacing)as not to have your tires sticking out 3" past the fender lip. It will look ALOT better, tuck in nicer, and track better making it easier to handle down track.

Sorry 'bout the novel.... kinda' got off on a tangent....
hope it helped-