With its bigger and bolder exhaust boring into our eyesockets, the 2008 Suzuki GSX-R600 makes its debut with some internal engine modifications.
In 2007 Suzuki fell behind in the ultra-competitive supersport class, both in our Supersport Shootout V and on the AMA racetrack. Suzuki is hoping for better results this year as it retools its supersport arsenal for 2008 with upgrades to the GSX-R600 and GSX-R750.
The 2008 GSX-R600’s oversquare 599cc displacement, with 67mm bore and 42.5mm stroke, remains unchanged this year, with the high-revving screamer still displaying a 16,000 rpm redline. The new Gixxer 600 does sport some internal changes, however, to its DOHC Inline-Four mill. The Zook’s Twin Swirl Combustion Chamber (TSCC) has a new shape to it, which engineers promise will “reduce shrouding of intake valves at low lift, enhancing cylinder charging and thus increasing power output.” Cylinder head refinements consist of more efficient intake ports and castings with thinner, lighter walls. The TSCC’s new shape combined with new forged aluminum-alloy pistons increases the compression ratio from 12.5:1 to 12.8:1.
Each cylinder head houses four titanium-alloy valves, with a pair of 27.2mm intakes and 22mm exhausts. Changes from last year’s design are the valve’s bucket tappets, with the intake’s 26mm tappets unchanged, but the exhaust side tappets swelling from 24mm to 25mm. Suzuki claims the exhaust tappet changes “work with a cam profile designed to increase acceleration coming off corners.”
Another internal engine modification for 2008 is the size of the ventilation holes linking the cylinder bores beneath the piston stroke, which have enlarged from 39mm to 41mm. Allowing the air to escape quicker, Suzuki PR promises the ventilation change “further reduces internal pumping pressure and mechanical power losses.”
Bore and stroke are identical to last year’s 599cc oversquare powerplant, but this year the GSX-R600 sports an increase in compression ratio to 12.8:1.
The refined mill also utilizes new 10mm NGK spark plugs, promised to deliver a hotter spark with a smaller, lighter 20mm ignition coil (down from 22mm). Suzuki also boasts a lighter more compact starter motor (0.342-lb lighter at 1.9 lbs) and a more powerful generator to keep the electronic systems juiced.
It’s no shock that last year’s slipper clutch is back. This time the back-torque-limiting design features a “new internal ribbing inside magnesium clutch cover and oil pan” to trim down mechanical noise.
Jumping out of the photos is the new exhaust, with the ’08 pipe bigger than last year’s stubby silencer. As expected, more stringent emissions standards are to blame for the larger triangular-shaped silencer. The Gixxer also features a Suzuki Exhaust Tuning (SET) butterfly valve to control back-pressure dependent on rpm, throttle and gear readings to maximize torque.
This year’s Gixxer Supersport features an all-new ECM (Engine Control Module). Lighter than last year’s model by 40 grams, the new little black box is also narrower and thinner. On top of controlling fuel injection, the ECM’s 32-bit processor crunches the numbers for the new Suzuki Drive Mode Selector (S-DMS), which now adorns the entire GSX-R lineup from the “little” 600 to the mighty Hayabusa. For those not in the know, the S-DMS provides three different engine maps: A, B and C, with the rider shuffling through the various settings via a switch on the right handlebar.
Updates to the Gixxer 600’s chassis is limited to the subframe, with the new aluminum-alloy design shaving 125 grams in weight.
The Suzuki Dual Throttle Valve (SDTV) is back for ’08, with the double-barrel throttle bodies carrying new injectors. This year the compact injectors have swapped out ’07’s four larger holes for eight smaller holes to increase fuel atomization. The primary injectors have been repositioned at a steeper 41-degree angle. Controlled by the ECM, the fueling is more efficient and along with the exhaust catalyzer and O2 sensor, ensures the Gix Six complies with tougher Euro-III and EPA emissions requirements.
The 2008 frame continues the five-piece cast aluminum design from its predecessor, along with the same aluminum-alloy swingarm. Changed for ’08 is the die-cast aluminum-alloy subframe, which shaves off 125 grams (0.28 lbs, or, in other words, a quarter pounder with cheese). Steering geometry is unchanged, with a 23.8-degree rake, 3.8 inches of trail and a 55.1-inch wheelbase. One change from last year is the 0.5-liter (0.13-gallon) increase in the fuel tank to 17 liters (4.5 gallons).
Showa suspension components also return for 2008, with an inverted 41mm fork up front and a rear shock out back. Adjustable for preload, rebound and compression damping, the two units provide a respective 120mm (4.7 inches) and 130mm (5.1 inches) of wheel travel.
The ’08 GSX-R600 wheels are lighter and stronger, with the aluminum-alloy units utilizing a new curved, three-spoke design. Although the same size as last year, the wheels’ weight differential compared to ’07 is 430 grams (0.95 lbs), with a 180-gram reduction up front and 250-grams in the rear. The wheels are shod with Bridgestone rubber.
With the addition of this year’s Gixxer 600 and 750, the entire GSX-R sport lineup utilizes the Suzuki Drive Mode Selector (S-DMS).
The braking system has seen a slight revision for 2008. Four-piston Tokico calipers, with staggered 30mm and 32mm piston sizes, still clamp down on 310mm rotors up front, but this year’s rotors have slimmed down from 5.5 to 5mm thick (a common move for the ’08 crop of sportbikes). The single-piston caliper/220mm rotor configuration in the rear also features a 5mm-thick disc.
The new styling digs for the Gixxer includes a wider fairing at the handlebar level meant to reduce drag, with the lower fairing slimmed down. Ram-air intakes were moved to the center of the fairing and they rest beneath a redesigned headlight assembly. The new headlights feature elongated highbeams flanking the central lowbeam. The analog tach and digital speedo display return, with the LCD display updated to include a display indicating what S-DMS setting the bike is running.
Now that the spec sheet and PR interpretation is done, the real question about the 2008 GSX-R600 will be whether the tweaks to the supersport machine is enough to gain ground on the class-leading Honda CBR600RR. We shall see.
The bike that changed everything when it hit the market in 1985, the GSX-R750 is back and displays many of the upgrades found on its 150cc-smaller sibling. As for what’s different from the GSX-R600, the obvious is the 70mm bore and 48.7mm stroke. At a respective 29mm and 23mm, the intake and exhaust valves are also larger than those on the 600. Unlike its smaller sibling, the Gixxer 750’s 12.5:1 compression ratio remains unchanged from 2007. The 750’s valve bucket tappets are also unchanged. An engine modification the 7-Fiddy does share with the 600 is the 2mm increase to 41mm for the ventilation holes linking the cylinder bores for increased efficiency.
Styling changes to the new GSX-R600 and GSX-R750 (above) include repositioned ram-air intakes and a new three-headlight assembly.
Other changes mirrored on the 750 and 600 are the larger exhaust silencer, new spark plugs, lighter starter motor and larger generator. The ’08 Gixxer 750 also utilizes the same ECM and showcases the S-DMS system universal now to the GSX-R sport lineup. The same is true of the SDTV fuel injection system and the switch from four large to eight small holes in the injectors for improved fuel atomization.
Changes, or the lack thereof, to the GSX-R750’s frame, brakes, wheels and styling are identical to the 600. Exiled from the major racing series, the ’08 Gixxer 750 will remain in a class all its own.
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