RIDING THE BEAST
We've dealt with previous custom big-horsepower bikes that required a strict regimen akin to defusing a time bomb--along with many prayers or acts of wizardry--in order to start. Instructions for firing up Voter's ZRX? "Just push the starter button," said Sims. After a second of turning over, the supercharged engine barked to life and idled smoothly, just like a stock machine. Sims and Voter just smiled.
Blipping the throttle revealed a hint of fluffiness off-idle, though nothing like some of the turbocharged bikes we've ridden. Once over that initial roughness, however, the rpms rise sharply at the slightest twist of the throttle as if the engine were breathing nitro. Of course, this blower isn't; with its low boost and compression, Voter's ZRX can live quite happily on a diet of pump gas without complaint. Which means you can ride it anywhere without strapping a jug of high-octane racing fuel on the back.
You'd think the blower drive unit on the engine's left side would interfere with the rider's leg, but it actually wasn't noticeable. What was noticeable was the sweet-sounding whine of the Eaton supercharger as the revs climbed and dropped; there's just something about that noise that lets you know some serious power is lurking in the engine bay. The custom Corbin seat has a nice rear lip to keep the rider in place during full-boogie launches, though as with most Corbins, we didn't like the way the edges cut into our thighs at stoplights.
Supercharger's Dyno Chart...
Supercharger's Dyno Chart
Dyno-graph mavens have surely noted the Voter ZRX's chart is simply amazing. At 5000 rpm, the engine is already producing an incredible 100 horsepower, with a monster torque curve that's as wide and flat as the Bonneville desert. Think about that for a second; that's 100 horsepower and 100 foot-pounds of torque at 5000 rpm, the same rpm you use cruising away from a stoplight on your streetbike. Needless to say, roll-on performance is astounding; unfortunately, we didn't have our radar equipment on hand to measure roll-on performance, but take our word for it--even though the bike is geared to the moon, there is basically no need to downshift. It's as if the throttle is directly tied to the speedometer needle.
Even with the outrageously tall gearing and the four-inch-over swingarm, the blown ZRX is a wheelie monster in the first three gears (actually, it should be called a "skyshot monster"--the front end comes up too abruptly and uncontrollably to be called a wheelie). It eats up the rpm range so voraciously it's a good thing the bike is equipped with a push-button air shifter, because otherwise the rev limiter would be getting a workout.
Ironically, that monstrous bottom-end power also proved to be a major problem at the dragstrip. Despite having Los Angeles County Raceway (LACR) personnel prep the launch pad, the blown ZRX would simply overpower the stock Bridgestone rear tire at the slightest provocation, burning up any decent 60-foot times in a cloud of rubber and smoke. The one time it did hook up, the front end immediately pointed at the nearest cloud formation, showing that perhaps an even longer swingarm would be necessary to unleash the bike's real potential. Nonetheless, even with the ZRX spinning wildly off the line, we still managed to rip off a 9.56-second pass with a 148.00-mph terminal speed, dwarfing the stock bike's 10.70-second/ 125.18-mph performance. We're confident a good rear tire and proper setup would yield times in the low-nine-second range without breaking a sweat.
"I could've easily mounted up a 60-cubic-inch blower with a higher-ratio drive [the current 45-cubic-inch unit spins on a 1.5:1 pulley system] and bumped up the boost to crazy proportions, but that's not what John wanted," confesses Sims. "We wanted to build a streetbike that stood out from the crowd, would start instantly, have good throttle response and overall engine manners while still offering instant monster power, and could run on pump gas." Only Richard Sims and the team at Muzzys would have the gumption to tackle such a project. But we'd have to say they succeeded on all counts.