S-DMS: It's Not Just For Big Bikes Anymore.
Like the GSX-R1000 and Hayabusa, the GSX-R600 now features Suzuki's Drive Mode Selector (S-DMS) technology that allows the rider to choose among three distinct power output profiles on demand, via a handlebar-mounted switch. A mode corresponds with full power output; B mode reduces power by roughly 20 percent across the rev range, while C mode cuts output by about 40 percent. A new, 32-bit ECM boosted with 1024KB of ROM (up from 384KB in '07) handles the math to manage S-DMS and some additional EFI functionality.
New forged-alloy pistons bump compression from 12.5:1 to 12.8:1. Changes to the intake-cam profile (lift has been reduced from 8.6 to 8.2mm) and exhaust system (header diameter has been reduced from 38.1 to 35.0mm) boost low-end and midrange power while still achieving the same peak output as last year, thanks to the across-the-board gains produced by the higher-compression engine. Underneath the engine resides a new, higher-volume Suzuki Advanced Exhaust System (SAES) with a servo-operated butterfly valve (Suzuki Exhaust Tuning, or SET) built into the mid-pipe to further enhance low-end performance, and a new, distinctly shaped triangular silencer at the terminus. Suzuki's Dual Throttle Valve (SDTV) fuel-injection system with two injectors per cylinder has been upgraded for '08 with new, finer-atomizing eight-hole injectors compared to last year's four-hole units. The throttle-body shape has also been revised, with the outlet diameter reduced from 40 to 36.5mm to increase intake airflow velocity. The motor also gets enlarged ventilation ports between the cylinder bores (increased from 39mm to 41mm), to reduce internal crankcase pressures and allow the pistons to more freely pump up and down.
The twin-spar aluminum frame is composed of five individual cast sections engineered to maximize rigidity and minimize weight. The die-cast aluminum subframe is now a two-piece design (split down the middle), to reduce weight and minimize damage in the event of a crash. The braced aluminum swingarm offers a larger pivot area to better transmit rear-tire feedback to the chassis. Helping to stabilize the stiffer chassis over uneven pavement is a new, electronically controlled steering damper that uses a tapered needle attached to a solenoid valve that automatically reduces or increases oil flow to adjust damping resistance according to speed and steering action.
Showa supplies the suspension front and rear. On the bow you'll find the same 41mm inverted fork as last year, with the standard twiddlers attached (preload, compression and rebound damping). At the stern resides a single 46mm shock, with adjustable preload and rebound as well as high- and low-speed compression ranges, for added tuneability. An extra-stiff, forged-aluminum shock linkage reduces side loads and enhances rear tire grip.
Wheels And Brakes
Lighter steering and quicker acceleration are the aims of the new, lighter-weight cast-aluminum wheels, which also feature a more modern, angled-spoke design. New 310mm brake rotors utilize 12 floating pins (compared to eight last year) for improved heat dissipation, and are reduced in thickness from 5.5 to 5.0mm to offset the added weight of the four extra buttons. Radial-mount, four-piston Tokico calipers (shared with the Hayabusa) are boosted by a revised front-brake master-cylinder ratio to improve lever feel and outright stopping power. Out back, a new caliper bracket makes it easier to remove the rear wheel or perform routine brake maintenance.