Blown Away--Supercharged Kawasaki ZRX1200

Designing the intake plenum and spigots to adapt the supercharger to the ZRX engine on paper was a straightforward task for Sims--but getting his drawings transformed into hard parts was another deal entirely. Thanks to the CNC machining and welding talents of Muzzys' Dale Sugano and Joe Keck, however, that task was made much easier. Sugano's handiwork is apparent in the beautifully machined aluminum billet (obviously) manifold that consists of two pieces; the front section has four spigots in the exact shape of stock inlet manifolds, smoothly transitioning to the rear portion, which is shaped like a velocity stack leading to the blower. Sugano was also responsible for crafting the entire blower drive setup (from Sims' specs) on the engine's left side. Keck welded the intake runners from the throttle body to the blower unit, as well as the blower drive cover.

The enormous job of mapping out the fuel injection from scratch was entrusted to Muzzys' electronic guru Rick Johnson. This was a long, tedious undertaking that required many weeks on a brake dyno (so the engine could be held at a specified rpm under load in order to properly adjust the fuel delivery), as well as constant road testing by Meyer. Compounding the difficulty of getting everything dialed in were the special fuel needs of a supercharger, which are much different from a normal engine. "With a blower, the fuel delivery needs to be changed right when the throttle is opened because the fueling needs will change before the rpm even rises," reveals Sims. "You also have to watch the air/fuel mixture readings carefully, keeping it in the 13-13.8:1 zone. Superchargers like to run richer than even turbos--and definitely more than normally aspirated motors--because of their high boost at low rpm characteristics."

The engine's bottom end consists of a Muzzys 1224cc big-block cylinder assembly, utilizing 81mm bores housing 9:1 compression ratio JE pistons specially made for forced induction applications. However, the rods and crankshaft (other than the special blower drive that was welded and then trued on the left end by Falicon) are completely stock. The cylinder head received a port job by Rob Muzzy, and the clutch is stock except for stiffer Muzzys springs. A programmable Muzzys air shifter allows full-throttle clutchless upshifts at the push of the horn button.

Trac Dynamics crafted the beautiful four-inch extended-wheelbase swingarm, which offers two mounting points for the twin rear shocks, allowing Voter to drop the rear end for major drag duty. He could've (and maybe should have, considering the bike's outrageous power, which will be covered later) opted for an even longer swingarm, but decided against it to keep with the bike's "streetable" theme. The shocks themselves are beautifully made Works Performance "Eddie Lawson Replica" piggyback units with dual springs; due to the shocks' forward/laid-down mounting, the reservoir on each shock is offset slightly to clear the rear subframe tab, a nice touch. Vortex sprockets (using much taller overall gearing in an attempt to keep the front end down) and a Tsubaki chain round out the drivetrain.