2008 Suzuki GSX-R750
The 2008 GSX-R600 and GSX-R750 would be perfect accessories at a roadracer's wedding: They have something old, something new, something borrowed-and they come in blue.
The closely related small- and medium-sized GSX-Rs were completely redone for '06. But in an effort to stay current-or ahead-in the demanding sportbike marketplace, the 600 and 750 have been restyled, refined and rethought for '08. The basic engines and chassis, and their vital dimensions, remain the same, but a raft of improvements distinguish them from their predecessors.
The 600's engine is essentially the same liquid-cooled, ram-air-equipped, 599cc inline-four we've come to know and love. Bore and stroke are unchanged at 67.0 x 42.5mm, but a reshaped Twin Swirl Combustion Chamber (TSCC) and accompanying new forged-alloy pistons bump compression from 12.5:1 to 12.8:1. Suzuki claims the reshaped chamber reduces shrouding of the intake valves at low lift, resulting in better cylinder charging and a small-but-significant increase in power.
The valvetrain received only slight upgrades: All four poppets are still titanium, 27.2mm intake and 22.0mm exhaust. The only change is bigger (25mm, up from 24) exhaust-valve buckets, which allow a new exhaust camshaft profile for increased acceleration.
The one-piece upper crankcase/cylinder castings now have thinner walls for reduced weight, and the new 10mm iridium plugs are said to deliver a hotter spark and a longer life. New smaller coils (20mm vs. 22) save another gram or two.
Enlarged ventilation ports (41mm vs. 39) in the crankcase reduce pumping losses, a serious consideration when your engine revs to 16 grand. The magnesium clutch cover and oil sump are new, with extra ribbing to add rigidity and reduce noise. The starter motor is smaller and 155 grams lighter, and the alternator makes more juice without growing in size or weight.
2008 Suzuki GSX-R600
The 600 has also borrowed the Suzuki Drive Mode Selector (S-DMS) from the GSX-R1000. The handlebar-mounted three-way switch lets the rider tailor the power curve to suit bad weather, thrashed tires or a sudden decrease in genital mass.
The new bodywork leaves the Cyclops aspect of the '06-'07 models behind, with the headlights wrapping farther around to the sides in a design that looks more like a face than an oncoming alien. There are three separate lights: the center one is low-beam and all three come on for high-beam.
The bodywork is slimmer on the bottom and wider at the handlebars, all in the name of reduced drag. The ram-air intakes have been moved to an area of higher pressure, and the previous mesh screens are gone, replaced by a louver system that is also claimed to increase air pressure to the throttle bodies.
Those double-barreled, 40mm throttle bodies are new, equipped with Suzuki Dual Thottle Valve (SDTV) technology and two new eight-hole fuel injectors each. The primary injectors have been re-angled for a straighter shot at the intake ports, and the secondary injectors, which come on-line in high-rpm and/or high-load situations, are re-aimed as well. The fuel injectors, secondary butterflies, exhaust butterfly valve and ignition are all controlled by a smaller, smarter ECU to optimize air, fuel and spark for any situation.
The 600 also gets a longer, larger-volume, triangular-section muffler, to meet new Tier 2 and Euro 3 emissions standards, and a computer-controlled butterfly valve still flaps in the mid-pipe under the engine, just upstream of the catalytic converter.
The slipper clutch and six-speed, close-ratio transmission are unchanged.
The aluminum main frame is unchanged as well, welded from five precision-cast pieces. The braced-aluminum swingarm uses both die-cast pieces and extrusions, and works with a motocross-style shock linkage and a four-way-adjustable Showa shock. The inverted 41mm, three-way-adjustable fork is also from Showa, and there's now a computer-controlled steering damper, replacing the previous always-on unit.
A new wheel design provides added lightness and enhanced rigidity, and thinner (5mm vs. 5.5) front brake discs and smaller disc mounting bolts decrease unsprung mass even further. The front rotors are still squeezed by four-piston, radial-mounted Tokico calipers, but more stretch-resistant brake lines and a smaller-diameter (17mm vs. 19) radial master cylinder are said to improve both braking power and feel.
The 2008 Suzuki RM-Z450 uses hardware modeled after that of the GSX-Rs to become the world's first mass-produced, fuel-injected motocrosser. Its chassis is also new, modeled after Ricky Carmichael's factory racebike. Handling is said to be sharper and smoother, with more powerful braking.
Chassis dimensions and riding position are unchanged: Wheelbase is 55.1 inches, rake is 23.8 degrees and trail remains 3.9 inches. Claimed dry weight has gone up, largely due to the porkier exhaust, from 354 pounds to 359.
The GSX-R600's sister ship, the GSX-R750, is not so heavily modified. It shares the new bodywork and ram-air system, three-position powerband selector, electronic steering damper and electronic upgrades, as well as the bigger, heavier exhaust. Its valvetrain is unchanged, but it does share the 600's new 41mm crankcase ventilation ports. And all the front brake and wheel upgrades made to the 600 are also present on the 750. Claimed dry weight for the 750 has crept up from 359 pounds to 363.