Suzuki GSX-R1000 technical

By Kevin Ash

Pictures: Suzuki Press

According to the GSX-R K9’s chief engineer, Hiroshi Iio, Suzuki reversed its traditional design philosophy by deciding on what chassis dimensions were needed to achieve the improvements in traction and agility that were required, then designing the engine to fit within those. Previously the engine was designed to be as compact as possible and the chassis was fitted around it. The basic need was for a shorter wheelbase and a longer swingarm, contradictory requirements that demand absolutely the shortest engine possible.



* Engine

Click on image for galleryThe key to getting the motor as short as the chassis parameters needed was raising the gearbox layshaft higher to bring the drive shaft and crankshaft closer together – making a taller triangle of the basic three-shaft layout. But almost everything else in the engine has changed too. The cylinders are redesigned to improve heat transfer and durability while the pistons, as well as being 1.1mm larger at 74.5mm, are a new design which is stronger with a different shape to accommodate the longer conrods.

To maintain the 999cc capacity the stroke is shortened to 57.3mm from 59.0mm, and with this change comes a reshaped combustion chamber, new cam profiles, a higher compression ratio (up from 12.5:1 to 12.8:1).

The crankshaft design incorporates more than the obvious stroke change, as the lubrication circuits are completely different. On the previous model the big ends were fed oil from the same circuit that fed oil to the main bearings, meaning that big end oil pressure was reduced compared with that at the mains. On the K9, there are two separate circuits, one feeding the mains, the other the big ends, resulting in more consistent and higher pressure at both sets of bearings. In turn this means less friction and greater durability.

Engine counter-balance shaft has smaller diameter bearingsSome internal friction is reduced by the use of smaller bearings in the counter-balance shaft, down from 23mm to 20mm, while other losses are decreased by the use of two springs per valve (the K7/K8 had one): a single spring will often resonate at certain rpm, causing uncontrolled waves to pass up and down and affect its ability to close the valve. This is countered by using a heavier than necessary spring, but there is a friction penalty. With two springs the resonance issue is reduced and the springs can be lighter, cutting the effort needed to rotate the valve train.

The cylinder heads have reshaped intake ports designed mostly to allow higher revs when the engine is tuned for racing. The valves themselves are 1mm bigger at 31mm inlet, 25mm exhaust, also improving the tuning potential. All the valves are made of titanium. For the first time in a Suzuki iridium spark plugs are fitted – these have very small central electrodes which result in a denser, hotter spark for a given voltage, and they also have longer service intervals.

Crankcases are in two pieces instead of threeThe crankcases themselves are new and come in two pieces rather than the three of the old version. The raising of the gearbox countershaft has allowed the crankshaft and the output shaft to move a significant 59.7mm closer together – this is the main contribution to the reduction in engine length.

The clutch has been redesigned with new friction material and a revised back torque limiter system and is now operated by cable instead of hydraulics for better feel, especially when pulling away from a standstill. 200g weight is saved by the integration of the clutch cover and starter motor cover.

Cooling is taken care of by a smaller radiator whose trapezoidal shape was developed on Suzuki race bikes. To compensate for its reduced size, the oil cooler is larger as well as trapezoidal instead of rectangular: the new cooler is capable of losing 6.13kW of heat compared with 4.53kW for the old model.

The air intakes for the Suzuki Ram Air Direct (SRAD) pressurised intake system are positioned close to the centre line of the bike, each side of the headlight assembly, and now feature louvres at the front rather than the mesh of the old bike, which improves airflow efficiency. There is also a small weight reduction because of this.

Race-developed trapezoidal radiator is smallerThe airbox is lighter without losing any of its capacity, while the intake funnels are reshaped for better efficiency, and can be shortened by 10mm to improve high end power for racing.

The exhaust system features titanium silencers and overall is 400g lighter than the K7/K8’s. The system continues to feature the SET (Suzuki Exhaust Tuning) valve, a butterfly in the downpipes which like the Yamaha EXUP disrupts pressure waves at low rpm which would otherwise interfere with cylinder scavenging. There is also a three-way catalyst and lambda sensor.

Despite the raft of changes, both the torque and power outputs are claimed to be the same as before, and even occur at the same rpm levels, according to Suzuki. The aim of the changes instead is said to be a smoother torque curve and power delivery and enhanced potential for higher revs. Which seems like a lot to achieve little that a road rider might notice.



* Chassis

The new twin spar aluminium frame is shorter than the K7/K8’s to accommodate the shorter engine, longer swingarm and shorter wheelbase (now 1,405mm, a 10mm reduction). The frame is designed with its welded joints mostly not visible from the outside, purely so it looks better. The swingarm is 577mm long, compared with 545mm of the previous version, but it’s also 0.5kg lighter. The three-spoke cast wheels are also lighter, by 180g at the front and 230g at the rear.

Monoblock Tokico callipers are 23 per cent stiffer than beforeThe GSX-R is now fitted with monoblock front brake callipers made by Tokico, resulting in a 23 per cent stiffness improvement compared with the old ones, and with other changes the front brake system is 0.56kg lighter overall. The hoses are claimed to expand less than the previous ones for improved feel. The rear brake is more compact and 0.29kg lighter.

The front forks are from Showa (Kayaba was used previously) and feature the new Big Piston design See Big Piston Fork feature here. Because the damping valves are larger the oil flow is slower and hydraulic lock is less of an issue. Also, because the fork springs are fully submerged in the oil, cavitation is less of a problem and the tendency for the oil to foam is reduced. The forks are also 0.72kg lighter, a major weight saving in this important region of the bike. Kayaba still supplies the electronic steering damper, which is revised for 2009 (it’s 45g lighter). This increases the damping force automatically at higher speeds.

Swingarm is longer and lighterThe rear shock is now Showa rather than Kayaba and is 0.3kg lighter, as well as being adjustable for low and high speed compression damping. More weight is saved by the use of extruded aluminium linkage components in place of the old forged aluminium ones. The use of a smaller piston and rod diameters (40mm and 14mm on the new, 46mm and 16mm on the old) contributes to reduced friction as well as the weight loss.



* Bodywork and functional

Aside from the obvious styling changes there are no significant differences between the new and old models, although the new dash display is more sophisticated and aerodynamic drag is claimed to be slightly lower despite wider bodywork in front of the rider’s knuckles.

* Suzuki GSX-R1000 K9 test