The trick to making a supercharger (Vortech S-trim, in this case) work with the returnless
As part of the full-boogie G-Trac suspension, the brakes have been up-graded to 13-inchers
Previously, we did a tech story with Steeda Autosports regarding bolting typical speed parts onto a brand-spankin'-new '99 Mustang GT (see "Agent 99," Jun. '99 issue). We marveled at how much power this car had right off the hauler, and were quite happy with the resulting 250-plus hp that the rear wheels put to the Dynojet after all the bolt-ons. Well, soon afterwards, we got a call from Steeda saying that they had taken it one step further by installing a Vortech S-trim huffer on essentially the same combination. And the results were astounding.
The biggest hurdle to overcome with installing a supercharger on the '99 Mustang is the fuel system, which does not use a return line. Pre-'99 supercharger kits use a fuel management unit (FMU) which increases fuel flow through the injectors by restricting the return line. That means you don't have to change injectors or burn a custom computer chip. The '99's fuel system won't accommodate an FMU, however, so the injectors and fuel maps have to be massaged.
After bolting the blower in place, Steeda replaced the stock injectors for 30-pounders, and added basically the same bolt-ons that we featured in the previous story--a 77mm mass air, throttle body, pulleys, K&N, and Flowmasters. The injectors and specially calibrated mass air meter were the key to making it all work with the new fuel system. With strictly bolt-on parts, and no custom computer programming, this sucker was thumpin' the rollers to the tune of 380 hp at the wheels, all the way up at 6,000 rpm. Power was still climbing when the rev limiter kicked in and spoiled the fun, so true peak power is probably a bit higher. Remember, this is a two-valve engine, not a Cobra!
Only a week or so after they got those numbers, the car was taken to the Fun Ford opener at Bradenton for a few exhibition runs. Forgetting to turn off the traction control, Steeda's driver ran a few mid-13s in the heat of the Florida spring day, and the rain postponed the effort for better times. A few weeks later, with Motor Trend's Jeff Bartlett running the clocks, "the yellow car" ripped off consistent 13.10s at 110, with one pass at 13.0 at 111 mph. This was on Nitto Extreme street radials (not drag radials), so the 60-foot times were dismal at 2.20 seconds. For those of you that live and die by 0-60 numbers, the car ran consistent sprints to 60 in 4.6 seconds.
Even more impressive is that the rest of the car carries the full Steeda G-Trac suspension, which is designed for cutting corners, not yanking a pair of skinnies a foot off the ground. The combination of short, stiff springs, road race shocks, and wide, heavy wheels and tires is most certainly not the hot ticket on the dragstrip. Throw a loose drag racing suspension and a set of slicks, or even drag radials, on this car and you're looking at a legitimate mid-12 second ride. With the G-Trac, though, the car is much more fun to drive on the street, especially when that street has some rad switchbacks!
As with any car Steeda builds, you can own this one, with all this stuff, including the trick Steeda 18-inch wheels, for around 34 large. Or, you could drop significant digits off that price tag by deleting the road race suspension and opting for a drag-specific setup. Could be just the thing to compete in the new mod-motor drag racing classes this year. Mid-12s with a two-valve should put you in the show. Steeda's number is (954) 960-0732, if your checkbook is willing.