The 5.0 Mustang is one of the most popular cars found today at the drag strip. Not without good reason either. The Mustangs good power to weight ratio from the factory. Along with the extremely large availability of both factory and aftermarket parts. Make her a great platform from which to build a fine racing machine. However the Fox-body Mustang is not without its shortcomings (nobody's perfect). The non parallel four link rear suspension, nose heavy weight bias, and several other factors. Leave a lot of room for improvement, thankfully most of them are easily remedied.
Lets begin with the tires, the tires are the main link between the car and the road. Making them the single most important part of getting your Mustang to launch correctly. The factory supplied rubber, Goodyear Eagles on most models. Are a fine tire, but not exactly optimized for drag racing. The short sidewall height, combined with the relatively hard rubber compound. Mean lots of wheelspin and black marks on the ground. So a change to a dedicated drag racing type tire is in order. For street driven cars drag radials are hard to beat, on a strictly track only ride racing slicks are what you want. Mustangs can use either a 26" or 28" tall tire with only slight massaging of the inner fenderwells. Use a 15x8" wheel with a 5.5" backspacing and you should be able to fit a 275/60x15 radial or a 28x12.5-15LT ET Street or a 28x10.5-15 slick. The difference is in the way the tires are measured, slicks are listed by tread width, the rest are given by section width(overall width).
While a 28" tall tire, like the above sizes is best for a high horsepower, supercharged, turbocharged or nitrous car. If your ride is mostly stock in the horsepower department, a 28" tire would definitely be overkill. One thing to consider is the weight of your tire, taller = heavier. Once your car launches that same tire now becomes a liability, because of rotational inertia. In other words if your car hooks fine with a 26" tire and does'nt spin excessively. It will actually be quicker with the smaller and lighter tire. If your budget constraints limit you to one set of tires the shorter tires are probably the way you want to go. A 28" tire will require a rearend gear change as well. Which is an extra expense that I'll discuss in a later chapter.
On the lighter is better topic, most factory wheels are ungodly heavy. Changing to a lightweight aluminum wheel like a Centerline or Weld Draglights, or if you're in the money a set of Bogarts. Will definitely shave some time off your 60' ET, as much as 1/10 second or more on some cars. Most wheels will require longer wheel studs to properly secure them to your ride. Safety rules say the stud must extend at least the diameter of the stud (1/2") into the hex portion of the lugnut. Radials are usually run tubeless, slicks and ET street type tires are generally run with tubes inside. Running tubes requires you to run screws through the bead. To prevent tire creep from ripping out your valvestems. 10-12 self tapping S.S. screws equally spaced around the bead on BOTH sides of the wheel should do the trick. Make sure the screws you use are long enough to go through the rim but not so long as to puncture the tire. Something around a #12 hex head x 1/2"-3/4" length should be good, (make sure you check though). Be sure to have your new wheels and tires professionally balanced before hitting the race track. Self sticking wheel weights work better than the hammer on kind most tire stores use. You might want to pick some up and bring them with you when you go to have them mounted.
Now that your Mustang has new shoes, its time to air them up. Buy a high quality tire pressure gauge made specifically for drag racing. The old pencil/stick type gauge is just not going to cut it anymore! My recommendation is to start on the high side of the pressure range (Do not exceed maximum pressure) and gradually lower the pressure 1-2 psi at a time. Keep checking your 60' times, look for the pressure that gives you the quickest time. After that you can vary pressures by 1/2 pound at a time to perfect your ride. Be wary of the fact that a drag slick with low air pressure is a hairy ride that takes a little getting used to, be careful! By now you should have lowered your ET by several tenth's of a second at least. Keep reading along with me and I'll bring you my best racing tips and techniques to make you the king of the strip!
Copyright 2010 by Tommy Gambon
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