Testing And Tuning Can Try One's Patience.
Going to the dragstrip is just one of the many things we Mustang enthusiasts like to do. For the MM&FF staff, it usually means covering a racing event or heading to Raceway Park in Englishtown, New Jersey, for a track rental. Track rentals are nice because we have the whole 1,320 to ourselves, and we're able to maintain an optimal racing surface throughout the day.
Since your author recently relocated to MM&FF's Tampa office, E-town rentals are, well, a thing of the past, so we took our resident supercharged '90 Mustang GT to the track-or tracks, as it were-to flog the ponycar amongst the masses.
To bring you up to date on our project ProCharged Pony, we'll start with the powerplant. Like many of our readers, we've bored and stroked the stock 302, as D.S.S. Racing built us a fine 331ci small-block that we topped with M2-ported, Brodix ST 5.0R cylinder heads and an Edelbrock Performer manifold. Pressurizing the intake tract is a ProCharger D-1SC centrifugal supercharger that makes about 17 psi of boost. A Comp Cams XE274HR camshaft orchestrates the atmospheric exchange between cylinders with a split duration of 274/282 and valve lift of 0.555/0.565 inch on a 112-degree lobe-separation angle.
Expelling the combustion remnants are a pair of Bassani long-tube headers that feature stepped primary pipes of 1-5/8-inch and 1-3/4-inch diameters. Past the collectors, a Bassani x style mid-pipe with catalytic converters carries the gases to Bassani's 2.5-inch after-cat exhaust system.
With HP Performance's Tony Gonyon wielding his SCT tuning prowess, the average-looking GT churned out 583 rwhp and 555 lb-ft of torque. As we mentioned in our D-1SC upgrade article ("Packing More ProCharger Performance, Part 2," Sept. '06), we were well past the recommended limit of our Level 20 D.S.S. stock block, so Gonyon pulled out four degrees of timing, leaving us with a mere mortal 518 rwhp to play with.
In the January '07 issue ("Six Ways to Slam Gears"), we upgraded the pony with a Tremec T56 transmission and chromoly drive-shaft from D&D Motorsports, and with the Drivetrain Specialties-built 8.8 rear axle, we were ready for some track time.
In order to get the power down, we needed some sticky tires, and while drag radials have become quite good lately, we were looking for a wrinkle-wall, bias-ply tire for traction. A 26x10.5x15 slick was our tire of choice, but we couldn't find anyone with a 15x8- or 15x9-inch rim with the 6.5 inches of backspacing we needed to get the tires under the car properly. We did mount up a 15x10 that had 6.5 inches of backspacing, but it stuck out way too far.
Another problem was the Cobra R rear disc brake setup, which has the rear brake line's banjo bolt positioned outward and in contact with the rim. Some people have ground these down to get the rim to fit, but that wasn't something we were interested in doing, especially considering it may be hard to remove the bolt later on. Another option would be to swap out the Cobra brakes for the smaller GT-spec disc setup, but since we couldn't find the right rim backspacing, there wasn't any point.
HP Performance's Sean Story graciously loaned us a set of 26x10.5x16 Mickey Thompson ET Street tires for our drag test. They work really well, especially when you actually put some heat into them.
Many SN-95 Cobra and Mach 1 owners utilize a 16-inch racing rim, and Bogart Wheels seems to be the only game in town for these. They're high-quality wheels and built to order, but they're also a bit pricey. After thinking about it for a while, they didn't seem worth the time or the money for a car that will rarely see the dragstrip. Why is that, you ask? Well, that leads to our next issue of having a street car with monstrous horsepower.
With the 331 churning out over 550 hp at the flywheel, our 3,360-pound GT should be capable of 10-second elapsed times. While that's fantastic, the car-and the driver, for that matter-aren't equipped with the necessary safety equipment required by most tracks to run that fast.
A six-point rollbar and five-point harness are necessary when running quicker than 11.49, and the driver should have an approved fire jacket as well. These are things that many street-car owners don't invest in because there just isn't a need, unless they want to run at their local 1,320 regularly. Some tracks are more lax than others, but these are pretty good rules, and it's in your best interest to follow them.