Posts Tagged ‘Suzuki GSXR 750’
Suzuki has definitely got the recipe right with the GSX-R series, starting with the 600 and finishing with the Hayabusa, but one particular bike gets our attention for one good reason: you don’t see this every day! The Suzuki GSX-R 750 situates just between a middleweight and a liter class sport bike, but offers its own kind of riding excitement.
With a fuel injected 750cc liquid-cooled, inline-four, DOHC and 16 valves engine improved by the always efficient and reliable six-speed gearbox, having both reached the highest levels of development and performance, there is no wonder why some riders simply can’t jump straight on the 1000cc GSX-R and choose the 750cc model as being the most adequate for them. Another good reason is the chassis, which makes it more of a sharp handler and confidence-provider, perfect for those who feel like going through all the steps in motorcycling.
A veritable super sport motorcycle that offers an enough comfortable riding position without sacrificing the racing appearance that practically sells it, the 2009 Suzuki GSX-R 750 is a light (437 lbs curb weight) and compact motorcycle that gives more than a clue on the powerful engine that sits behind that nice looking fairing.
Given to the shape of the bike, once the rider takes the top speed position, he is practically part of the aerodynamic design of this GSX-R. All pieces unite perfectly to create a winning puzzle combination: the air intake, headlight, signal lights and windscreen result into a wind tunnel master. The gas tank, well positioned into the frame, allows enough space for the rider to tuck into the fairing while the seat is positioned almost horizontally, setting the GSX-R series apart from more aggressive accommodating bikes and yet which have the same results.
- Electronic fuel injection system features Suzuki Dual Throttle Valve (SDTV) system – with dual fuel injectors per cylinder and new compact 8 hole, fine spray injectors for improved fuel atomization.
- S-DMS engine management system allows the rider to choose from three engine settings to match riding conditions with a handlebar mounted switch
- Under deceleration the back torque limiting clutch reduces pressure on the clutch plates for smoother downshifting and corner entry.
- Aluminum clutch cover and oil pan feature internal ribs for increased rigidity and reduced engine noise
- Suzuki Idle Speed Control (ISC) system for improved cold starting, consistent idle quality and reduced emissions
- High volume Suzuki Advanced Exhaust System (SAES) with an innovative under engine chamber leading to a large volume muffler with a distinctly shaped triangular silencer
- Hydraulic cam chain tensioner automatically adjusts while reducing noise and mechanical losses.
- Ignition coil outer diameter is smaller for reduced weight and the starter motor uses new rare earth magnets for a compact lightweight design
- 32 bit ECM features 1024 kilobytes of ROM for maximum engine performance working in conjuction with the new S-DMS engine management system
- Compact 4-stroke, 4-cylinder, liquid-cooled engine designed for optimum combustion efficiency and maximum power delivery
- Cylinder head with narrow valve angles creating a compact combustion chamber design, 12.5:1 compression ratio, large intake and exhaust ports for optimum intake and exhaust efficiency and new Iridium spark plugs
- Lightweight titanium valves with steel alloy springs and aluminum spring retainers operated by thin-wall hollow camshafts to reduce weight and inertia
- Lightweight forged aluminum alloy pistons with short skirts, cut away sides and an anti-friction surface finish along with shotpeened chrome-moly steel connecting rods for improved strength
- Crankshaft features forged steel construction and a secondary balancer shaft for reduced vibration at high rpm.
- Crankshaft and transmission shafts are positioned to create a compact engine design and the engine itself is rotated slightly forward in the chassis allowing for straighter and shorter intake and exhaust ports
- High capacity large trapezoidal-shaped radiator provide efficient engine cooling – includes compact cooling fan assembly designed for improved air flow
- SRAD ( Suzuki Ram Air Direct) force feeds cool, pressurized air into the airbox at highway speeds, improving engine efficiency and throttle response.
- The 2009 GSX-R750 features a sharp and aggressive look utilizing a bold new headlight design, angular tail section and compact overall layout
- Electronically controlled steering damper uses a solenoid valve to move a tapered needle reducing or increasing oil flow to adjust damping force.
- Lightweight cast aluminum wheels featuring an angled spoke design for improved rigidity, reduced unsprung weight and improved acceleration
- Inverted 41mm Showa cartridge front forks are fully adjustable for high and low speed compression, spring preload, and rebound damping
- Radial mount four piston front brake calipers works with 310mm front brake rotors and a radial pump front brake master cylinder
- ’09 GSX-R750 fuel tank features an innovative design and fuel capacity is 4.5 gallons
- The lightweight frame is built entirely of aluminum alloy castings and is engineered to deliver optimum rigidity, unmatched accuracy and maximum cornering performance.
- A braced aluminum alloy swingarm features a large 22mm swingarm pivot and is designed for optimum rider feel and maximum rear wheel traction
- Innovative rear suspension linkage utilizes a forged aluminum alloy link and a forged aluminum link rod that reduces side loads and helps the rear shock absorber move in a smooth arc
- Showa 41mm aluminum alloy rear shock with a 16mm rod diameter are fully adjustable for high and low speed compression, spring preload and rebound damping for maximum rider control
- Three way adjustable footpegs now feature die-cast construction and can be moved into three different positions with a 14mm horizontal and vertical range
- Compact, lightweight instrument cluster features a step motor controlled analog tachometer, LCD speedometer, dual trip meters, clock and a convenient gear position indicator.
The original GSX-R set a design theme Suzuki engineers have followed with success ever since: Make the GSX-R respond to the rider and do what the rider wants, when the rider wants, how the rider wants. The GSX-R750 has consistently outperformed anything else in its class, proving the slogan, Own The Racetrack. Would-be competitors finally gave up racing against the GSX-R750, and then stopped building 750 Supersports altogether. The 2011 GSXR 750 features advanced engine technology, with broader power delivery, improved throttle response, lower emissions and about 10-pecent better fuel mileage as measured by Suzuki engineers using the standardized Worldwide Motorcycle Test Cycle.
Efficiency By Design
Combustion efficiency, for example, is a measure of how completely an engine burns its fuel. Better combustion efficiency can increase power and torque output across the rpm range; improve throttle response, acceleration and fuel mileage; and reduce emissions.
Mechanical efficiency is a measure of how much of the power and torque produced by an engine actually reaches the rear wheel. Reducing mechanical losses by minimizing internal engine friction, reducing the weight of reciprocating internal parts and relieving crankcase pressure can increase mechanical efficiency, putting more of an engine’s output to use actually moving and accelerating the motorcycle and also improving fuel mileage and reducing emissions.
Performance efficiency is best expressed by the power-to-weight ratio, or, the comparison of a motorcycle’s output to a motorcycle’s weight. The more power and torque the engine makes and the less the motorcycle weighs, the better the power-to-weight ratio becomes. In turn, a better power-to-weight ratio can produce stronger acceleration, better fuel mileage and reduced emissions in many situations.
The new GSXR750 features a completely new chassis designs, based on a more compact, lighter twin-spar aluminum frame with a 15 mm shorter wheelbase. The GSX-R750′s wheelbase is now 1390 mm.
Rotating the engine rearward by 3 degrees around the countershaft sprocket made it possible for the engineers to reduce the distance from the front axle to the swingarm pivot while maintaining the race-proven steering geometry and without losing the needed clearance between the front wheel and the radiator at full wheel travel.
The shorter wheelbase better centers the combined machine/rider mass between the wheels, improving racetrack cornering and also shortening the reach between the seat and the handlebars. The shorter reach and slightly wider handlebar angle make it easier for the rider to reposition their weight while on the racetrack and also improve comfort on longer highway rides.
Each GSX-R 750′s main frame is built using five welded-together castings. But changes in the size and shape of the main spar castings and the relocation of the connecting welds contributed to a 1350 grams significant reduction in frame weight for each model and also allowed the engineers to adjust torsional rigidity and enhance racetrack cornering. Each frame is also narrower at the seat, making it more convenient for the rider to reposition their weight for cornering on the racetrack.
The inline four-cylinder engine is liquid-cooled with Suzuki Ram-Air Direct (SRAD) induction and a digital engine management system. Double Overhead Camshafts (DOHC) are driven by a link-plate chain off a forged crankshaft and open four titanium valves per cylinder through bucket tappets, with shim-under-bucket lash adjustment. The valves are set at a narrow angle, 22.5 degrees for the GSX-R750, allowing a very compact Twin Swirl Combustion Chamber (TSCC)-with the intake valves set at 10.5 degrees from the cylinder centerline. The exhaust valves are set 12.0 degrees from the cylinder centerline.
The engine is oversquare, which means that it has a larger bore and a shorter stroke, producing a race-proven bore/stroke ratio which contributes to better efficiency and allows higher rpm. High-compression, forged aluminum three-ring slipper pistons feature cutaway sides and ride on short wrist pins carried by shot-peened chrome molybdenum steel connecting rods. The rectangular upper compression ring and the oil control ring on each piston feature a chrome-nitride coating applied in a vacuum using a Physical Vapor Deposition (PVD) system.
The chrome-nitride coating is harder and smoother than conventional chrome plating, reducing friction and improving cylinder sealing; the rectangular upper compression ring is pushed out against the cylinder wall by combustion pressure, reducing blow-by and further improving cylinder sealing.The four-into-one stainless-steel exhaust system features four individual head pipes and a single collector. The mid-pipe located between the collector and the under-engine exhaust chamber carries a Suzuki Exhaust Tuning (SET) servo-controlled butterfly valve to match exhaust system back-pressure to engine rpm, throttle position and gear position, maximizing torque and improving throttle response, especially in the low-to-mid rpm range.
The GSX-R features a repositioned engine management computer (also known as the Engine Control Module, or ECM) to allow the wiring harness to be simplified and made lighter. The ECM operates a state-of-the-art Suzuki Dual Throttle Valve (SDTV) closed-loop fuel injection system, an advanced ignition system and several emission control systems, producing better throttle response, smoother power delivery, improved mileage and reduced emissions.
The secondary valve is controlled by the ECM, which monitors engine rpm, primary butterfly valve position (or how much throttle the rider has selected) and gear position, then opens or closes the secondary butterfly valve incrementally to maintain 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 emissions.
The primary injector for each cylinder has been repositioned at a shallower, 35-degree angle from the throttle-body centerline, spraying atomized fuel below the primary butterfly valve and directly down the intake port, improving throttle response. Each cylinder’s secondary injector is mounted at a 15-degree angle and is aimed to bounce sprayed fuel off the secondary throttle valve, improving atomization and combustion efficiency while also contributing to more linear throttle response.
The Suzuki GSX-R750 comes with the revolutionary, race-developed Showa Big Piston Front-fork (BPF) inverted front suspension system. Conventional inverted front forks use a cartridge assembly that fits inside the fork leg on each side and typically incorporates a 20 mm piston to control damping.The BPF design also has minimized change in internal fork pressure throughout the stroke, improving response to small bumps and racetrack surface imperfections. And because the fork springs are relocated to the bottom of each fork leg where they are completely submerged in oil, foaming is reduced and damping performance remains more consistent.