Kosman Racing Gsx-R1254
KOSMAN RACING GSX-R1254
PRO-STOCK LOOKS, DMV APPROVED
SPECIALIZATION IS A WONDERFUL THING, AND Sandy Kosman, major domo of Kosman Racing (340 Fell St., San Francisco, CA 94102; 415/861-4262) knows that very well. Kosman specializes in building drag-racing chassis, leaving the art of engine building to others.
Kosman’s approach to the CW “Built for Speed" project was to purchase a common streetbike, send its engine out to be breathed upon and then modify the bike’s chassis to excel in the quarter-mile.
He started with a 1987 Suzuki GSX-R ll00, the engine from which he sent to Orient Express Racing (375 W. Sunrise Highway, Freeport, NY 11520; 516/ 546-5232). He got back a monster motor which developed, without air filters, 170 horsepower on Orient Express’ dyno, and, Kosman estimates, 155 to 160 horsepower with individual K&N air filters installed.
Modifications to the engine included installation of a I254cc big-bore kit, Megacycle camshafts, Mikuni RS40 smooth-bore carburetors with special slides machined by Orient from billet aluminum, a rev limiter set for 13,000 rpm and a Murray Engineering exhaust system. The cost of this engine upgrading was $4639-about $27 per horsepower.
Kosman then added to the GSX-R’s chassis his $495 drag-racing swingarm kit. This is six inches longer than stock and is mounted solidly to the bike’s frame, eliminating the shock, spring and suspension linkage to lower the bike’s center of gravity. This he topped with his company’s pro-stock-style seat and tail section, a $295 assembly.
He then installed his own modular wheels, machined from billet aluminum, and he lowered the bike’s front end and added a steering-damper kit, adjustable-offset triple clamps, 310mm Kosman discs and Lockheed four-piston calipers as well as Lockheed master cylinders for both the front brake and the clutch. Yokohama radial tires were mounted.
Finally, Kosman added an electronic shift kit from Dale Walker’s Holeshot Performance (311 Chestnut St., Santa Cruz, CA 95060; 408/427-3625). This uses sensors on the shift-lever shaft which kill the bike’s ignition whenever the shaft is in motion or not fully notched into position, allowing lightning-quick, clutchless upshifts while, theoretically, making it impossible to blow an engine with a missed shift.
The Kosman GSX-R 1100 made at once the worst street ride (no rear suspension, no lean angles, especially on left turns, where the gear-shift lever dragged the pavement) and the best street ride (that engine, those aggressive looks) that we’ve ever experienced. And in its natural environment—any stretch of pavement 1320 feet long-this bike works so well that its deficiencies as an all-around motorcycle seem unimportant.
At a total of $7194, plus the cost of the base GSXR, duplicating the Kosman bike is for neither the faint of heart nor the faint of wallet. But if you’ve simply got to have a stoplight-to-stoplight street racer, you could do worse than own a bike like this one.
—Jon F. Thompson
