Steve Baur
Former Editor, Modified Mustangs & Fords
February 12, 2010

We began the test with Gonyon making a few runs on the 275/40/17 NT555R drag radials that were already on the car. He started with an 11.21 at 125 mph (1.79 60-foot time) and followed this with an 11.11 at 125.33 (1.77 60-foot). Gonyon has lots of experience on drag radial tires and we felt he was getting as much from the 555s as could be had without spinning excessively. He was launching hard, but wasn't going wide-open on the immediate hit.

With our baseline times on record, it was time to bolt up the NT05R drag radials. Nitto sent us a set of 315/35/17s and we called up American Muscle for a set of its deep-dish 17x10.5 Bullitt-style wheels with an anthracite finish. They looked great against the Mustang's Mineral Gray paint, and the 10.5-inch width allowed the 315 to plant squarely on the pavement. It also fit the SN-95 chassis perfectly and without any modifications.

Airing the tires to 15 psi, Gonyon loaded up and headed to the starting line. Getting acquainted with the tires, Gonyon laid down an 11.09 at 123.97 mph (1.62 60-foot time). On the next pass, Gonyon added 5 pounds of air pressure to the tires, but got out of the throttle down track, as the transmission went into overdrive. Feeling that the tires could use a bit more air pressure, we added 5 more psi for a total of 25. The first 60 feet vanished in 1.59 seconds, and the Mustang crossed the stripe in 10.94 seconds at 124.79 mph.

Feeling the NT05R's were offering plenty of traction, Gonyon made a change to the computer calibration, adding two degrees of timing to get more power from the 4.6L. The Nittos ate up the power and bit hard-Gonyon rocketed to a 10.80 at 125.33 mph (1.60 60-foot). He then backed that up with a near-identical 10.80 at 126.38 (1.60 60-foot time).

"I was impressed," said Gonyon. "I didn't expect them to perform that well, and I think we could have gone faster-I probably could have gone up more in air pressure, too. The 555Rs are going to be better in the rain and bad weather, but I' rather have the NT05R at the track-most people don't drive cars like these in the wet anyway."

Those that have found the limits of the NT555R will no doubt find the NT05R to be what they need; it should open the eyes of a great many who use other brands as well.