    |
 |
|
|
|
Although Suzuki has recently added the World Endurance Championship, the AMA Superbike Championship and the World Superstock Series to the growing list of credits for its class-leading GSX-R750, it isn’t resting on its laurels.
Consequently, it has an all-new model ready for release, and amazingly, it’s faster, lighter and more powerful than the model it supersedes.
Amazing because the current GSX-R750 is already the fastest and the most powerful 750cc sports bike available.
However, rather than waiting for rival manufacturers to even get close to the GSX-R750, Suzuki has upped the ante with the all-new fuel-injected GSX-R750Y, continuing the trend it started with the original model back in 1985.
That motorcycle stunned the motorcycling world because it was the first 750 to crack the 100 bhp mark and at 179kg, it was by far the lightest 750 in production.
Apart from the powerful air and oil-cooled engine of the original, it was the GSX-R750’s weight advantage over its competition that won it so many fans.
Now, 15 years later, Suzuki is about to release an all-new GSX-R750 that weighs 166kg (dry) and cranks out a stunning 140 bhp.
Starting with the chassis, Suzuki has produced a more compact frame that’s 10mm shorter front to back and 13mm lower from top to bottom. The frame is also lighter than the current model and its torsional rigidity to weight ratio has improved 10 per cent.
The new chassis was designed in conjunction with the new even more compact engine, which remarkably is 15mm shorter front to rear, 8mm narrower and 6mm shorter from top to bottom and weighs a useful 5kg less than the current motor, which is already an extremely compact design.
At the same time, power has been bumped up by 6 bhp.
Engine weight savings have been achieved through the use of hollow, thin wall camshafts, lighter and stronger connecting rods and forged instead of cast pistons. Weight savings continue through the use of magnesium alloy for the camshaft cover as well as the clutch, starter, alternator and countershaft sprocket covers. The sump pan is also made of magnesium alloy.
The biggest change from previous Suzuki practice sees the cylinders are now cast integral with the upper crankcase half. As well as being lighter and stiffer, this also allows Suzuki to use cast-in oil passages, with lubricating oil routed from the pump through the upper crankcase and cylinder, with internal passageways distributing oil throughout the head.
The clutch has been revised with the diaphragm spring replaced by coil springs for better feel at the engagement point while there’s a revised lever ratio for the cable.
Like the 1998 and ’99 GSX-R750s, the new Suzuki features electronic fuel-injection with all new throttle bodies that feature twin butterfly valves to smooth part throttle engine response. When the throttle is opened, the primary butterfly, which has a throttle position sensor on the end of its shaft, opens. A servo motor controlled by the engine management system controls the second throttle butterfly. This is opened and closed to maintain maximum intake air velocity, resulting in more seamless and linear throttle response.
As well as the twin butterfly intakes, Suzuki has altered the position of the injectors in the throttle bodies to spray directly on the primary butterfly when it is between halfway and fully open. Suzuki says this results in better fuel atomisation leading and more complete combustion, with more power and reduced emissions the twin benefits.
Other power enhancing changes include repositioned intake ducts for the ram-air system that feeds high pressure air from the nose of the fairing to the airbox.
On the suspension front, the GSX-R750Y again uses a set of Showa inverted forks with 43mm diameter stanchion tubes but travel has increased by 5mm to 125mm while the fork legs are 7mm closer together to help reduce frontal area and also provide less steering effort.
At the rear, a piggy-back shock with a 75mm stroke offers 130mm of wheel travel. The shock features a larger bore damper piston made in aluminium alloy for greater heat dissipation and reduced weight.
To enable the new GSX-R750Y to be banked more easily and quickly into corners, the rear tyre has switched from a 190/50 ZR17 to a 180/55 ZR17 while the front remains a 120/70 ZR17.
This new model GSX-R should be on dealers’ floors in April 2000.
Contact the online Suzuki dealers for more info:
Phil Turnbull Motorcycles
Ingram & Worsley
Red Baron
