Suzuki Sets the Standard

SUZUKI SETS THE STANDARD

YOU MAY ASK WHY THE world needs an intensified Suzuki GSX-R1000 when that CW Ten Best winner is already deep into the realm of “too much is just enough.” The answer is that AMA and World Superbike racing will soon adopt a straight 1000cc displacement for twoand four-cylinder machines. That being so, this $10,499 T-Rex of liter-bikes gets a few last tweaks before the new drama begins.

Power and durability under load are increased. The engine ECU’s ability to handle information has also been boosted, controlling not only fuel-injection and ignition, but also Suzuki’s exhaust-wave control valve, which boosts off-peak torque and cuts emissions.

The dohc, 16-valve, 988cc engine employs forged three-ring pistons and shot-peened chromoly steel connecting rods. Forging increases piston fatigue strength, and shot peening does the same for the rods by placing the metal’s surface into compression via the impacts of steel shot. These measures increase reliability under stress.

Much is made of airflow through cylinder heads, but pistons also pump air back and forth in the crankcase, a process that consumes several horsepower at high rpm. Therefore, 10 ports have been pierced through the crankcase webs (two per web) of the integrated platedbore cylinder and upper crankcase above the main ings. By enlarging and shortening the airflow path from one bore to the next, these set free horsepower previously consumed as pumping loss.

Engine balancer shafts can’t directly boost performance, but a motorcycle’s chassis must be made heavy enough to survive whatever vibration the engine produces. Large-bore inlineFours generate a buzzy secondary shaking force, arising from the twice-per-revolution angling of the connecting rods, causing a corresponding cyclic variation in piston position. This engine has a front-mounted secondary balancer, geared to the crank, to cancel this high-frequency shaking. Freed of this, the chassis need no longer be overbuilt. The resulting lighter weight yields stronger acceleration. The former 16-bit CPU, with 96K of Read Only Memory is now replaced by a 32-bit unit with 256K of ROM, increasing information-processing speed. Likewise, the engine speed sensor is upgraded from an eightpole to a 22-pole trigger wheel. This gives the CPU more detailed information about engine speed variation at lower rpm, increasing the accuracy of fueling and ignition timing.

Chassis geometry is unchanged but chassis beams are now stiff, internally divided aluminum extrusions. Rigidity has been adjusted using information derived from the GSR-V

four-stroke MotoGP bike. Internally divided extrusions also form the swingarm beams. For racing, pivot location can be altered as on the GSX-R750based Yoshimura Superbikes.

Radially mounted Tokico four-piston calipers bolt to 43mm fork tubes, whose sliding friction is reduced by use of a “Diamond Like Carbon” coating. Increased caliper braking force allows front disc Suzuki’s V-Twin SV650 has been hailed as the universal, fun-toride motorcycle. Its willing power and reassuring handling have made it a favorite among club roadracers as well.

For ’03, the newly revised SV continues as two machines-a $5899 naked bike with a tubular handlebar and a single chrome headlight, and a $6299 half-faired “S” version with twin “cat-eye” headlights, clip-on handlebars and a sportier riding position. Both variants now have multi-element LED taillights. Other changes include a new cast-aluminum chassis that is 7 pounds lighter than before, and the adoption of electronic fuel-injection.

The new chassis consists of sand-cast steering head and uprights, which are welded to vacupower. Suzuki’s dual-throttlevalve injection is used, controlled by a 16-bit ECU. Exhaust emissions are further cut by Suzuki’s pulsed secondary air-injection system, which valves airbox air into the engine’s exhaust ports, where it combines with unbumed hydrocarbons.

Wear-resistant cast 11.5:1 pistons join to fatigue-tolerant shot-peened chromoly steel con-rods on a single crankpin. The engine’s 90-degree cylinder angle gives the SV650 full cancellation of primary vibration.

What if you like the concept, but 650cc isn’t enough for your kind of fun? Suzuki now adds the $7999 SV1000 and $8599 SV1000S to the family. The 90degree 996cc V-Twin is a descendant of the previous TL1000, but with its first-generation fuel-injection replaced by SDTV as on the SV650. The bigger engine features forged pistons and shotpeened rods, plus an ECU related to that used in the GSX-R1000, with a fast 32-bit processor and 22-pole rpm signal generator. A diameter to be cut from 320 to 300mm. Overall machine weight savings total 4.4 pounds over the 2002 model. Let the battle begin.

A battle of another sort is raging on the streetfighter scene. On the middleweight front, um-die-cast, internally ribbed side trusses. A 41mm conventional fork carries four-piston brake calipers and twin 290mm discs.

Fuel-injection combines emissions compliance with crisp throttle response and maximum Superbike-derived back-torque limiter on the hydraulically actuated clutch frees the rear wheel from excess engine braking during downshifts or rapid deceleration.

So, what’s your pleasure? -Kevin Cameron