Ultimate S1

ULTIMATE S1

Thunderin' Lightning

WITH A PENCHANT FOR stoppies and wheel ies, Buell's Si has built a reputation based on its hooligan street manners. But a serious side to the Si also exists, as evidenced in the Buell Lightning Series-a spec roadracing class pitting lightly modified Sis against their own.

However, for Team Corbin Motorcycle Online, beating similar Sis just wasn't enough. For the past two seasons, the team has also developed and raced an Si in NASB's EBC Sportbike class, the rules of which mandate a 1 02-horse power maximum, 395-pound weight minimum and the use of DOT tires. It's a formula that's tailor-made for 600cc inline-Fours.

Making inroads into a regime ruled by Japanese 600s hasn't come easy. "Last year we ran the gamut of hightech drag-racing engines-big bores, special crankshafts, huge carbs and cams pushing gigantic lifts. All to no avail," states Shawn Higbee, a former factory Ducati Superbike rider who joined Team Corbin MO this year, taking over engine-building and riding duties. Now, the motors are essentially stock with two key performance mods boosting power to 102 bhp: 1) a set of Bartels' cus tom-ported and reshaped cylinder heads and 2) American Air-Cooled Cylinders' nickel-silicon-carbide-coated alu minum cylinders. Beyond that, the rest of the motor is largely stock-including cams-the exceptions being a 42mm flat-slide Mikuni, a race header and muffler, a Screamin' Eagle ignition box and an S2-style air filter.

L~.i `U,LIi1I1 5L~ L~11LLI~JA1 LJ~.JI~ t1I1~.L (411 L7A..~LJ 1%' 1411 Chassis changes are minimal, mostly a Fox shock, a steering damper and a Ferodo staggered-eight-piston caliper with a small-diameter brake line. A Renthal chain conversion was also necessary due to a lack of gearing selection available for the stock belt drive.

The bike currently checks in right at 102 bhp and strad dles the weight minimum with a splash of fuel in its tank. Its best showing to date is a sixth place at the series' Portland round. The team feels a win is near, but just in case, development continues on a short-stroke, light-fly wheel, high-revving motor already on the workbench.

Don Canet