Suzuki's New Big Gun
SUZUKI'S NEW BIG GUN
ROUNDUP
FILEXIBILITY, USABILITY and tailoring engine output to the rider's needs are the future for sportbikes. Or let us say, these things are the present, as the 2007 Suzuki GSXR1000 makes evident.
The ever-increasing role of electronics in managing performance is apparent here, because the ’07 GSXR1000 has a three-position switch on the right handlebar that controls mapping to tailor engine output to conditions. Settings are billed as fitting “wet,” “mixed” or “dry” track conditions, using tuning information gathered from racing.
No output figures have been released, but the engine changes suggest what may have been achieved over the previous model’s 154 horsepower at the rear wheel. While the 73.4 x 59.0mm bore and stroke of the 999cc inline-Four remain the same, cooling capacity in the trapezoidal radiator has been increased by 10 percent, while the intake and exhaust ports have been increased in size by 8 percent. This would indicate a peak-power increase of as much as 10 percent. An additional 8 hp wouldn’t be out of the question. More interesting will be midrange output and the shape of the torque curve. The GSX-R1000’s torque curve was a work of art last year, beautifully bountiful and linear. Can this be maintained in the face of “more aggressive” camshafts, those bigger ports, 2mm larger exhaust valves (now 26mm) and while also complying with morestringent emissions standards? Certainly Suzuki is doing everything possible to maintain excellent power by using double the exhaust volume (with twin silencers and large under engine chamber) as compared to the 2006 model, while retaining an exhaust powervalve and the excellent dualbutterfly throttle system.
New 12-hole injectors replace the old four-hole units and atomize fuel more effectively, while the secondary injectors are re-angled to shoot more directly into the intake ports for improved throttle response.
Coping with the multi-map function and more complex tuning schemes has led to the engine-management computer being equipped with four times the processing power of the old unit. Added to its duties is control of the active steering damper featuring a solenoid-actuated needle valve to vary effect according to riding conditions, a system similar to that fitted to the Honda CBR1000RR.
Five main castings make up the all-new GSXR1000 frame, reducing parts count and the number of welds in manufacturing. Weight is reduced, tolerances are tighter and the delicate mix of stiffness in some areas and flexibility in others has been changed yet again. A lighter, stiffer swingarm and new shock mounts and linkage improve rear traction. The 43 mm inverted fork, like the shock, features highand low-speed compression-damping adjustments. As was the case with last year’s 600/750, a key change on the 1000 is that the rider has been moved forward, toward the center of the wheelbase, and the fuel tank is shorter to accommodate this. Also, like on the smaller GSX-Rs, three-position adjustable footpegs are used.
Material was removed from the brake discs by making them 0.5mm thinner in the same 310mm diameter. Because the loss of material can lead to overheating (not enough heat-sink), the number of carrier “buttons” has been increased from eight to 12 to provide more heat paths into the carrier.
The ridiculously limited specs (so much To Be Determined, except the $11,399 price) provided by Suzuki leave a lot of questions unanswered about the GSX-R1000. One thing is certain: This bike will be a contender come shootout time.
Mark Hoyer
