SUVs are roomy, practical, versatile, and-fast? Consider the supercharged Silver Streak shown here. It started life as a Mercury Mountaineer, certainly a capable vehicle, but hardly our first choice for high-performance thrills. Great for climbing mountains, but not for dropping the hammer on the drag strip. That shimmering, quicksilver Spectraflair paint on this modified SUV is more than just for looks, though. The Silver Streak lives up to its name, thanks to a Kenne Bell twin-screw blower, reportedly the first one ever installed on a Mountaineer.
SUV enthusiasts might get caught up admiring the custom Katzkin upholstery and those 20-inch chromed-alloy Oasis rims shod with Toyo Proxes S/T (265/50R20) tires. But, you know you've got the beans to kick their butts around the block. The supercharging pros at Kenne Bell crafted a whole new realm of power for the Mountaineer's 4.6-liter V-8 by bolting on its twin-screw supercharger kit and Optimizer II Engine Management Computer (to reprogram fuel, spark and shift points). For better breathing, a K&N Filtercharger and a low-restriction after-cat performance exhaust system were also added.
Unlike other Ford applications done by Kenne Bell, the Silver Streak presented some new challenges, because of a different type of computer that required six months' worth of tedious programming to re-flash the chip. Fortunately, on the fuel side, things were somewhat simpler. Other Ford vehicles often use a return line, which can create some problems with octane loss when fuel delivery is increased for the blower (due to increased heat from friction at the orifices). Jim Bell (the Bell in Kenne Bell) points out that the Mountaineer doesn't have a return line, so all he had to do was install larger injectors (42 versus 24 pounds) and his Boost-a-Pump for upping the fuel flow.
Rather than installing a larger fuel pump (which would entail dropping the fuel tank and possibly add to tailpipe emissions), the Boost-a-Pump increases flow by simply bumping up the voltage on the fuel pump from 12.5 to 16 volts when a pressure switch is activated under boost. At cruising speed, however, the pump flow remains stock, so there's no sacrifice of fuel economy-until you stomp your right foot, of course.
No Dog Water.
All told, at a healthy six pounds of boost, the engine's stock output increases by as much as 40 to 50 percent, depending on octane and other variables. For instance, although Ford claims an ideal output of 239 hp at the flywheel, on Kenne Bell's dyno it showed 210 hp (and 168 hp at the rear wheels). Force-fed by six pounds of boost, the engine produced 315 hp at the flywheel. Bell says that if you multiply that by 0.8, it comes out to a rear-wheel-and real-world-figure of 252 horses.
With anything lower than 92-octane go-juice, though, the horses pull up lame. Figure on a loss of 10 hp for every 1.0 drop in octane. The point is clear-when you're running a blower, you can't fill up with dog water for fuel.
Matching the Silver Streak's looks with its performance are several subtle but classy touches, such as an AMP Research billet fuel door, a red mesh screen behind the grille, and Katzkin custom leather upholstery. For in-flight entertainment, Clarion supplied an audio system and KVE a video player. Woodview spiffed up the interior with dash and cockpit trim. And for the right stance off the starting line, Intrax springs lowered the vehicle three inches. All of which means this Mercury not only delivers the goods, but also looks good when it delivers.