THE ORIGINAL KEEPS GETTING BETTER
With the GSX-R750
, we virtually invented the 750cc supersport class. In creating a new version, we knew we had a lot to live up to. And as our racing experience has taught us, it's the details that make the difference.
This new engine is the most efficient we've ever built for the GSX-R750
As before, it's a liquid-cooled DOHC unit with Suzuki Ram-Air Direct (SRAD) induction and a digital engine management system. Built oversquare, its bore/stroke ratio is the same one we give our race bikes, allowing it to rev higher and run leaner.
Every component has been minutely analysed, then manufactured in the perfect material offering you optimium performance. The cylinder block and upper crankcase are cast as a single unit in aluminium alloy. The valves – four per cylinder – are titanium, the connecting rods are shot-peened chrome molybdenum steel and the pistons are aluminium.
The cylinder bores are plated with our own race-proven nickel-phosphorus-silicon-carbide coating, known as Suzuki Composite Electrochemical Material (SCEM) which reduces friction and improves heat transfer, durability and cylinder sealing. Even the ventilation holes in the cylinder walls are
pentagonal, rather than circular, to improve gas flow and save weight.
The secret to this engine's remarkable efficiency lies in the Engine Control Module, or ECM. This controls the Suzuki Dual Throttle Valve (SDTV) closed-loop fuel injection system, which gives each cylinder its own pair of butterfly valves and compact fuel injectors. The primary butterfly valve is linked directly to the throttle grip by a cable, giving the rider a positive, instantaneous response.
The secondary valve is controlled by the ECM, which maintains the ideal intake air velocity for improved cylinder charging and more efficient and complete combustion. The result is more linear throttle response, increased torque and reduced
The system uses fine-spray injectors, each with eight small holes for improved fuel atomisation. As well as the primary injector, which operates all the time, there's a secondary injector, which introduces more fuel when the engine is working hard at high revs. Using a sensor built into the exhaust system, the ECM monitors the exhaust gases and adjusts fuel delivery for more complete combustion, further reducing emissions.
The new ignition circuit, developed in MotoGP, uses individual ignition coils firing 10mm NGK spark plugs fitted with iridium-alloy electrodes. These produce a hotter spark, resulting in more complete combustion, improved throttle response and longer service life than conventional spark plugs.
The new GSX-R750 is leaner and cleaner than any previous model. But it still sounds the way it should, thanks to its four-into-one stainless-steel exhaust system. In the mid-pipe is the Suzuki Exhaust Tuning (SET), a servo-controlled butterfly valve that matches exhaust system back-pressure to engine rpm, throttle
position and gear position. What you get is maximum torque and a sharper throttle response, especially in the low-to-mid rpm range.
And because this is a race bike at heart, the titanium end-pipe has been redesigned for improved aerodynamics and cornering clearance – and with thinner walls and a new exhaust chamber, it's 1.04kg lighter, too.
The original GSX-R750
defined what a 750cc supersports bike should be. With this new engine, we've stayed true to that unique heritage, while making this a bike very much for our own times.