Get Us The Engine Room
The S281 SC comes with a special domed and vented hood to clear the Saleen-spec, twin-screw supercharger and its integrated long-runner intake manifold. The Series VI supercharger pushes 2300 cc of air per rotation versus 1600 cc for last year's Saleen blower. According to Saleen, the supercharger turns slower for equivalent boost, producing lower stress and lower air charge temperatures. This allows for a smaller, lighter, and more compact intercooler with virtually zero pressure drop from inlet-to-outlet side.
The supercharger also features an integrated bypass for low-speed operation, which reduces heat buildup in the engine, and the intake produces more torque and better low-end driveability. There is a free-flowing air filter and specific tune in the computer for the blown Saleen.
Helping on the exhaust side is a trick muffler system that is shared by all S281s, supercharged or not. The two mufflers (with center-exiting tips) have vacuum-activated valves that open above a specific backpressure. Essentially, think of them as factory-installed dumps. When the baffles are closed you get a nice rumble; shove your foot into it and you get a rambunctious note that will scare small animals and get the attention of any John Q. Laws in your vicinity.
All this is rated at 400 hp at 5,800 rpm and 420 lb-ft of torque at 4,000 at a 91-octane friendly 3.5 pounds of boost. Why so little boost? That's all it took to reach the 400hp bogey.
Based on its trip to the Crazy Horse Racing chassis dyno (South Amboy, New Jersey), Saleen is being rather modest with its rating system. Shocker No. 3: Our example almost made 400 hp to the rear tires--390.6 to be exact. That's probably around 450 to the flywheel. Torque checked in at 387.9.
And you need every bit of this at the strip, as weight (with driver) checked in at a Crown Vic-esque 3,880 pounds. Welcome to the world of 2-ton Mustangs.
At said dragstrip (Old Bridge Township Raceway Park, Englishtown, New Jersey), the Saleen was quite capable. Test pilot Evan Smith kicked things off with a conservative 12.81 at 109.22 mph. After a brief cooldown, he blistered the tarmac with a 12.508 at 110.42. He backed that up with a 12.654 at 110.43. That was as good as it got. No amount of changes to the shift strategy or launch techniques would improve on the 12.50. This puts the S281 Supercharged right in '03-'04 SVT Cobra territory, acceleration-wise, a sizable improvement over the 300-horse '05 GT.
Serendipity struck again as we were able to test an '05 Corvette coupe with an automatic transmission and full aftermarket exhaust a couple days earlier (with near identical weather conditions). Despite being hamstrung with 3.08 gears, it still stopped the E-town clocks at 12.314 at 113.80. Our guess is that if you run into a six-speed Vette with 3.45 gears, you'll need to swap blower pulleys if you want to keep up. On the road course, the Vette and Saleen were neck and neck, with the S281 SC registering the best lap time by 0.22 second.
Having driven both cars at the road course, it was remarkable how similar their tendencies were. Whereas the stock '05 Mustangs plowed miserably on the tight course, the Vette and Saleen were incredibly neutral. Oversteer could be induced at will with the introduction of throttle; the steering and brakes inspired confidence. Both the plastic Chevy and S281 felt more like race cars that coddled you in luxury, while the stock Stangs were decent handling, fun-to-drive street cars that would absolutely frustrate the driver during athletic maneuvers.