Big Brother, the GSXR1000 gets significant udates for 2004. 

The new 2004 Suzuki Supersport Machines
Biggest changes featured in the class leading GSXR-1000
Complete details of the GSX-R600, 750

Updated for 2004 Suzuki GSX-R1000 - The reigning AMA Superbike Champion
Powering the '04 GSX-R1000 is a potent 988cc four-stroke, DOHC, liquid-cooled inline-four-cylinder motor with a bore and stroke measuring 73mm x 59mm. The engine benefits from forged aluminum-alloy pistons, chrome-moly-steel, shot-peened connecting rods, lightweight hollow camshafts and Suzuki Composite Electrochemical Material (SCEM) coating on the cylinder bores. In addition, ventilation holes between cylinders reduce internal crankcase pressure for improved torque at high rpm.

The '04 GSX-R1000 makes use of the Suzuki Dual Throttle Valve (SDTV) digital fuel-injection system with dual double-barrel throttle-body set-up. Controlling the fuel injection is an advanced ECM system with a powerful 32-bit CPU and 256 kilobytes of ROM for optimum and precise fuel injection at all rpm ranges. Exhaust gasses are expelled though a lightweight exhaust system featuring a titanium core muffler covered with an aluminum outer pipe. Mounted within the titanium exhaust system and working in conjunction with the SDTV system is the Suzuki Exhaust Tuning (SET) valve, which automatically adjusts to improve low-to mid-rpm performance and reduce emissions.

A black-painted aluminum-alloy twin-spar frame houses the powerful GSX-R1000 motor. It utilizes extruded main frame spars welded to a cast steering head and pivot plate section. The extruded frame rails feature two internal reinforcing ribs for unmatched strength and light weight. The ribs also allow for greater rigidity control and improved handling under heavy braking and cornering. A lightweight yet strong rear subframe assembly is mounted directly to the back of the main frame.

Up front, the Kayaba 43mm inverted cartridge fork offers fully adjustable spring preload, rebound damping and compression damping. The fork tubes are coated with Diamond Like Carbon (DLC) for low friction and increased durability. Bringing up the rear is a Kayaba piggyback-reservoir shock, adjustable for spring preload, and rebound and compression damping. It's mated to a black-painted, externally braced, aluminum-alloy swingarm.

Brakes are race-spec. Radial-mount, four-piston Tokico calipers grip 300mm rotors in front, while an opposed-dual-piston caliper and 220mm rear disc mount directly to the swingarm. Cast-aluminum-alloy wheels measure 3.50 x 17 inches in front and 6.0 x 17 inches in the rear. Radial tires complete the ensemble.

The GSX-R1000 is sharply styled and its fairing houses multi-reflector, vertically mounted headlights for a narrow profile, improved aerodynamics and highly effective ram air system. This narrow theme is carried throughout the machine with the slim tank and sleek tail section.

The GSX-R gauge features a white-faced stepping motor analog tachometer, digital LCD speedometer, odometer/tripmeter, clock and water temperature readouts. LEDs are also used for the turn signal, high beam, neutral and fuel level indicators. Additionally the GSX-R1000 comes equipped with a programmable engine-rpm indicator that can be used as a shift light.

The 2004 GSX-R1000 - GSX-R (K4) AT A GLANCE
Suggested Retail: $10,499.00 Engine Type: Four-stroke, liquid-cooled
DOHC, inline four-cylinder Bore and Stroke: 73.0mm x 59.0mm Front Brake: Dual Radial Mount Hydraulic Disc Rear Brake: Single Hydraulic Disc Wheelbase: 55.5 inches (1410 mm) Dry Weight: 370 lbs. (168 kg.)

GSX-R600
It all starts with the engine. The '04 GSX-R600's liquid-cooled inline-four-cylinder, DOHC powerplant features four valves per cylinder, fuel injection and a precision six-speed transmission. Bore and stroke are an over-square 67.0mm x 42.5mm, producing 599.4cc of displacement. The cylinder block is integrated with the upper crankcase and the aluminum cylinder bores come plated with Suzuki's race-proven nickel-phosphorus-silicon-carbide coating, called Suzuki Composite Electrochemical Material (SCEM) for reduced weight and increased durability.

Many changes have been made to the newest GSX-R600 in an effort to reduce mechanical losses and increase power to the rear wheel. The crankshaft itself has smaller main journals -- 30mm instead of 32mm -- and carries lighter chrome-moly-steel connecting rods. The new rods are shorter, lighter by 10 grams, shot-peened for strength and allow for a more compact cylinder block. All-new forged pistons have shorter skirts and the skirt wall is slightly thinner. These changes make each piston 18 grams lighter. As before, the wrist pin utilizes a tapered bore for even more weight reduction.

The upper compression ring and oil-control ring are now finished with a chrome-nitride plating utilizing a Physical Vapor Deposition (PVD) system. Charged vaporized chrome-nitride is electro-deposited on the ring faces, which carry an opposite charge. The chrome-nitride coating is harder and smoother than conventional chrome plating for reduced friction and a more consistent finish.

N ew ventilation holes between each cylinder have been added, reducing internal crankcase pressure at high rpm and increasing torque. When combined with the shorter cylinder block, this results in an integrated upper crankcase that's lighter by 500 grams.

The all-new cylinder head for the GSX-R600 features a more compact combustion chamber with a higher compression ratio, narrower valve angle and straighter intake port. Intake ports are now 10 degrees (13 degrees previously) from the cylinder centerline, while exhaust ports are 12 degrees (15 degrees previously) reducing included valve angle from 28 to 22 degrees. The steeper valve angle results in a smaller combustion chamber volume, in turn increasing compression ratio from 12.2:1 to 12.5:1. The GSX-R600 also receives a new lightweight flat-top piston for more complete and efficient combustion.

Straighter and steeper downdraft angle (49 degrees from the cylinder head gasket surface) is another benefit of the narrow valve angle. These straighter, steeper intake ports reduce intake flow resistance, improve cylinder charging and combustion efficiency as well as allowing the cylinder block to be 8mm shorter front to rear and 80 grams lighter. The cylinder head bolts are shorter and lighter by 3.5 grams each, while exhaust ports are larger (32mm as opposed to 30mm) to reduce exhaust-flow resistance.

Lightweight titanium valves previously only seen on factory race bikes are at home in the new GSX-R600 powerplant. Each 27.2mm intake valve weighs in at 5.6 grams lighter than traditional valves for a combined weight savings of 44.8 grams. Exhaust valves measure 22.0mm each and are 4.4 grams less than previous valves for a combined weight loss of 35.2 grams. Smaller and lighter bucket tappets operate these titanium valves, and give the steel-alloy springs 10 percent lighter spring rate. The result is a 1350rpm increase in maximum engine speed. Valve spring retainers are aluminum.

Valves are opened by hollow camshafts with thinner walls and inner diameters of 16.5mm. The intake camshaft is 45 grams lighter and the exhaust camshaft is 35 grams lighter. New internal passageways carry oil to the automatic, hydraulic cam chain tensioner, saving an additional 50 grams. The radiator is 40mm narrower, 2mm thinner but 10mm taller, resulting in the same cooling capacity with a weight savings of 125 grams. The electric fan features a new one-piece design. The oil-to-coolant oil cooler is thicker, with eight layers instead of six for increased oil cooling capacity.

Like other GSX-R models, the '04 GSX-R600 uses the innovative Suzuki Dual Throttle Valve (SDTV) digital fuel-injection system. The new GSX-R600's double-barrel throttle bodies are 370 grams lighter than the previous bank of four individual throttle bodies and use lighter-weight fuel delivery pipes. Each throttle body is now larger on the intake side (growing from 41mm to 46mm) and tapers down to an unchanged 38mm at the cylinder head. Fuel injectors are positioned at a steep 60-degree angle and now have multi-hole tips for better fuel atomization and increased combustion efficiency.

The center-to-center spacing between each throttle body has been reduced to 75mm, making the assembly more compact and creating a narrower air box and fuel tank at the rider's knees. Also new for the GSX-R600 is an Auto Fast Idle System (AFIS), which improves cold starts by monitoring coolant temperature and automatically adjusting idle quality.

Controlling the advanced fuel-injection system is a smaller and lighter ECM with a more powerful 32-bit CPU and increased ROM from 98 kilobytes to 256 kilobytes. The crankshaft position sensor is also improved with a 22-pole (as opposed to eight-) trigger for a more precise fuel-injection volume calculation.

A four-two-one stainless-steel exhaust system features a larger titanium core muffler with an aluminum sleeve with slash-cut tip. The titanium/aluminum muffler combo is about 700 grams lighter than a steel-core muffler and 300 grams lighter than an all-titanium set-up. The GSX-R600 uses Suzuki's reed-valve-controlled Pulsed-AIR (PAIR) injection system with larger PAIR passageways (8mm from 6.7 mm), which increase the volume of fresh air reaching the exhaust ports.

Anchoring the GSX-R600 is an all-new black-painted twin-spar aluminum-alloy frame and swingarm. The combo features a 54.7-inch (1390mm) wheelbase, 23.6 degrees of rake and 93.1mm (3.66 inches) of trail. Each frame spar is made from an extrusion divided into two internal sections by a single internal rib. This new type of spar is slightly taller and thinner than the previous GSX-R600 frame spars and allows Suzuki engineers to adjust vertical and horizontal rigidity, which provides better feel under hard braking and cornering. The new frame is 15mm narrower at its widest point and 5mm narrower at the swingarm pivot.
The new frame also incorporates a revised rear subframe that bolts directly to the main frame for improved durability. Other refinements for the GSX-R600 include a more compact fuel tank and repositioned footpegs for increased rider mobility and banking angle. The seat-to-handlebar measurement was reduced and seat height was lowered by 5mm.

The 43mm inverted Showa cartridge forks offer adjustable spring preload, and rebound and compression damping settings. A matching Showa three-way-adjustable, piggyback-reservoir shock with larger diameter is fitted at the rear. The black-painted aluminum-alloy, externally braced swingarm comprises extruded main arms, an extruded pivot tube, a stamped deck integrated with a cast cross brace and cast axle carriers. The GSX-R600 rolls on 3.50 x 17-inch front and 5.50 x 17-rear wheels with radial tires.

Brakes for the new GSX-R600 are heavily upgraded for '04. All-new race-proven, radial-mount, four-piston Tokico calipers are mated to a Tokico radial pump master cylinder for improved lever feel and performance. Two 300mm floating discs complete the race-ready front brake package. The rear disc measures 220mm and works with a dual-opposed-piston caliper mounted directly to the swingarm, eliminating the conventional torque link rod.
Distinctive bodywork is as aggressive as ever and incorporates improved aerodynamics and a more effective ram-air system. Thanks to the slim frame and sleek bodywork, the overall package is now even narrower than before. All-new vertically stacked headlights allow ram-air intakes to be positioned 10mm closer to the centerline where air pressure is highest. This significantly increases airbox pressure for improved cylinder charging and engine performance.

The upper headlight is a multi-reflector unit housing a 60/55-watt H4 halogen bulb positioned above a 55-watt H7 projector low beam. Taillight treatment is a compact, maintenance-free LED set-up that complements the redesigned tail section and smaller turn signals.

The instrument cluster features a black-faced analog tachometer powered by a stepping motor, an LCD digital speedometer with a combined odometer/tripmeter, and clock display. LED turn signal, high-beam, neutral, fuel-level warning, FI warning, coolant temperature warning and oil pressure warning indicators are also used. Lastly, a programmable built-in rpm indicator light can be used as a shift light, triggering at a pre-selected engine speed.

The 2004 Suzuki GSX-R600 - GSX-R600 (K4) AT A GLANCE
Suggested retail: $ 7,999.00
Engine Type: *four-stroke, liquid-cooled
DOHC, Inline four-cylinder
Bore and Stroke: *67.0mm x 42.5mm
Front Brake: *Dual Radial Mount Hydraulic Disc
Rear Brake: *Single Hydraulic Disc
Wheelbase: *54.7 inches (1390 mm)
Dry Weight: *354.9 lbs. (161 kg.)
** Specifications not final

2004 GSX-R750: Superbike Benchmark
The Suzuki GSX-R750 is more than just a motorcycle -- it is the cornerstone of the GSX-R line. Indeed, it is the original GSX-R. When the original GSX-R750 was introduced in 1985, it established an entirely new class of machine. The GSX-R750 took over the grid in production-based roadracing worldwide, becoming the race bike of choice for an entire generation of roadracers.

And now, Suzuki introduces the all-new 2004 GSX-R750. Since the beginning, the GSX-R750 has been about overall balance of handling and engine performance. For 2004, the GSX-R750 takes that balance to an entirely new level with an improved compact, lightweight design that creates an awesome combination of handling, performance and style.

The '04 GSX-R750 retains its basic race-winning layout from the previous versions. It utilizes a bore and stroke of 72.0mm x 46.0mm, producing 749.2cc of displacement. The liquid-cooled powerplant continues to use four valves per cylinder, Suzuki Dual Throttle Valve (SDTV) fuel injection and aluminum cylinder bores electro-plated with Suzuki's own nickel-phosphorus-silicon-carbide coating called Suzuki Composite Electrochemical Material (SCEM). Other competition-proven components include lightweight forged pistons mated to chrome-moly-steel, shot-peened connecting rods and a high-performance six-speed transmission.

The 2004 GSX-R750 benefits from a series of refinements designed to reduce weight and mechanical losses, increase engine output and improve power delivery while reducing exhaust emissions. Thus, it is the most efficient 750cc engine ever built by Suzuki.

The refinements start with a more compact combustion chamber with a higher compression ratio of 12.3:1, versus the previous version's 12.0:1. The new combustion chamber requires a reshaped piston with a flatter crown and reshaped valves without indented head faces. Valve angles remain at 12 degrees on the intake and 13 degrees on the exhaust from the cylinder centerline. Valve size also remains 29mm on the intake side and 24mm on the exhaust end with a 4mm stem. The big difference is that the valves are now made of titanium instead of steel. Each intake valve weighs 7.2 grams less than its steel counterparts and the exhaust valves are 6.0 grams lighter for a combined weight savings of 105.6 grams. The big advantage comes in the reduction of reciprocating mass and inertia forces, which allows for higher maximum rpm with valve springs specifications that are 25 percent lighter in rate. That lighter spring rate means reduced mechanical losses and increased horsepower and torque. Valve springs are of a special steel-alloy construction and use aluminum retainers.

Lightweight hollow camshafts with thinner walls have internal diameters increasing from 15.5mm to 16.5mm. This produces intake camshafts that are 45 grams lighter and exhaust camshafts that are 35 grams lighter. Lighter pistons and a new piston-ring treatment also contribute to improved horsepower and higher rpm limits. The skirts on each forged piston are shorter overall, reducing piston height from 40.7mm to 39.2mm. Thinner walls mean the pistons are each 15 grams lighter for a total weight reduction of 60 grams. The faces of the top compression ring and oil control ring on each piston are now coated with chrome-nitride applied in a vacuum chamber using Physical Vapor Deposition (PVD). This chrome-nitride coating is harder and smoother than conventional chrome plating, resulting in reduced friction and increased durability.

Intake ports are 2 percent larger than before, with exhaust ports growing 2mm (32 mm vs. 30 mm). The distance between the centerlines (pitch) adjacent to the ports has been reduced for a more compact fuel-injection assembly. This allows the airbox and fuel tank to be narrower by 20mm at the rider's knees. The outside intake ports have been angled inward, reducing pitch between cylinders one and two, and between cylinders three and four from 80mm to 75mm. The pitch between cylinders two and three remain at 80mm.
New ventilation holes in the upper crankcase between the cylinder bores help to equalize crankcase pressure, reducing internal crankcase pumping pressure and increasing torque by about 2 percent. Handling the increased performance of the GSX-R750 is a new trapezoidal-shaped aluminum radiator developed in the factory racing department. The aluminum liquid-cooled oil cooler now has eight layers of coolant passageways instead of the previous model's six for improved cooling capacity.

The Suzuki Dual Throttle Valve (SDTV) fuel-injection system for the new GSX-R750 has also been upgraded for '04. Dual double-barrel throttle bodies replace the four individual units used on past versions, reducing weight by 370 grams and simplifying the throttle linkage. Internal dimensions remain unchanged. New injectors feature multi-hole tips instead of conventional pintle-type tips for a finer spray and better fuel atomization. A new Auto Fast Idle System (AFIS) improves cold starting, while a smaller and lighter ECM boasts a faster 32-bit CPU with 256 kilobytes of ROM for more precise and accurate operation throughout the rev range. Additionally, the crankshaft position sensor has 22 poles instead of eight for increased engine rpm signal accuracy.

The four-two-one exhaust system is stainless steel throughout with a larger titanium core muffler for improved performance and reduced weight.

The GSX-R750's aluminum twin-spar frame is painted black and incorporates a cast steering head and plated swingarm pivot mated to a pair of extruded main frame spars. Each main spar has an internal reinforcing ribs running lengthwise, allowing Suzuki engineers to adjust vertical and horizontal rigidity for improved handling and feel under hard braking and cornering. The main spars are taller and thinner than before and the rear subframe mounts are redesigned for improved durability. Wheelbase has been reduced from 55.5 inches (1410mm) to 55.1 inches (1400mm). Rake remains at 23.6 degrees while trail has been changed from 96mm (3.78 inches) to 93mm (3.66 inches).

Showa inverted 43mm forks are fully adjustable for spring preload, and rebound and compression damping, and produce 120mm of wheel travel. Out back, a matching Showa piggyback-reservoir rear shock features the same adjustments and provides 130mm of wheel travel.
Tokico four-piston radial-mount front brake calipers and 300mm discs provide increased stopping power and reduced drag. Braking performance is further improved due to a racing-influenced radial piston front brake master cylinder. This unit more directly transfers lever travel into stopping power, creating improved brake feel. The rear brake uses a 220mm disc and a dual-opposed-piston caliper mounted directly to the swingarm, eliminating the torque arm.

Wheels are made of cast-aluminum, with a 3.50 x 17-inch front carrying a 120/70ZR17 radial tire and a 5.50 x 17-inch rear wheel carrying a 180/55ZR17 radial tire.

The new GSX-R750's aggressive and distinctive new look features vertically stacked headlights that are narrower than before. This improves aerodynamics and reduces frontal area significantly. The latter allows for ram-air ducts to be positioned 10mm closer to the fairing centerline, providing maximum efficiency and increased airbox pressure. The multi-reflector headlights use a 60/55-watt H4 halogen bulb mounted above a projector low beam using a 55-watt H7 bulb.

The reshaped fuel tank is 15mm shorter and 20mm narrower at the rider's knees, providing better aerodynamics and increased range of motion. The overall seating position for the '04 GSX-R750 has been improved in that the seat-to-handlebar measurement was reduced for increased rider mobility. Out back a more compact LED taillight resides under a redesigned tailsection, completing the aggressive new look of the GSX-R750.

Instruments for the 2004 GSX-R750 include a stepping-motor analog tachometer, digital LCD speedometer, odometer/tripmeter/clock combo, LED turn signal, high-beam, neutral and fuel level indicator, as well as a new LED rpm programmable LED rpm indicator light.

The 2004 Suzuki GSX-R750 - GSX-R750 (K4) AT A GLANCE
Suggested Retail: $ 9,499.00
Engine Type: *Four-stroke, liquid-cooled
DOHC, inline four-cylinder
Bore and Stroke: *72.0mm x 46.0mm
Front Brake: *Dual Radial Mount Hydraulic Discs
Rear Brake: *Single Hydraulic Disc
Wheelbase: *55.1 inches (1400 mm)
Dry Weight: *359.3 lbs. (163 kg)
*Specifications not final

GSX-R750 (K3) AT A GLANCE
Suggested retail: $ 9,449.00
Engine Type: Four-stroke, liquid-cooled Bore and Stroke: 72.0mm x 46.0mm
Front Brake: Dual Hydraulic Disc, Rear Brake: Single Hydraulic Disc
Wheelbase: 1,410mm (55.5 in.) Dry Weight: 166kg (365 lbs.)