When we last left the GSX-R1000, it was in dire need of an update. It had gradually picked up pounds over the years to the point that it was now the heaviest of the literbikes by a good margin, and its formerly class-leading engine had become an also-ran in the chase for class supremacy. Even its superb steering and handling characteristics had long since been surpassed by the competition. No doubt about it, the Suzuki is a prime example of what can happen when you've lain dormant since '07.
Wait a second…that's only two years, right? And we're talking about the GSX-R as if it's some dinosaur whose time has long since past?
Yep. Two years—heck, even one year—is all it takes to go from the latest and greatest to the back of the pack in a class as competitive as the literbike category. The pace of development has ramped up to unbelievable levels, and sitting still for just a moment often means getting left behind by an ever-improving pack.
Definitely Not The Same Ol' Gixxer
We initially previewed some of the basic changes to the new GSX-R1000 in our January issue ("New GSX-R1000 for '09"), but the important details finally came to light at the U.S. press introduction held at the high-speed confines of Willow Springs International Raceway in Rosamond, California. Unlike the previous bi-annual changes that were evolutionary in scope, the K9 model is truly an all-new machine from the ground up, with very few components interchangeable with the old model.
New forged aluminum pistons...
New forged aluminum pistons (above) were designed around the new 0.5mm longer connecting rods (right) in order to gain more leverage over the course of the crankshaft’s power stroke and retain much of the older engine’s midrange power.
Although the previous generation K8 engine was a superb powerplant (as evidenced by its continuing dominance of AMA Superbike), Suzuki saw the writing on the wall and knew the next version would not only have to be lighter and more compact, but also need to rev higher in order to produce more power. This resulted in a new more oversquare bore/stroke layout, with a 1.1mm-larger bore (now 74.5mm) paired with a correspondingly 1.7mm-shorter stroke (now 57.3mm); nonetheless, the GSX-R still has the longest stroke in the literbike class. By combining the new forged aluminum pistons with new 0.5mm longer connecting rods for more leverage over the course of a crankshaft power stroke, Suzuki engineers aimed at retaining the previous generation engine's strong midrange power while also permitting higher top-end power potential.
The larger bore permitted 1mm larger titanium valves on both intake and exhaust (now measuring 31mm intake and 25mm exhaust) along with dual valve springs replacing the previous single units for better control at high rpm. An incremental boost in compression ratio from 12.5:1 to 12.8:1 was made possible by a slightly shallower included valve angle (the exhaust valve angle changed from 13 degrees to 12.5 degrees, for an included valve angle of 24.5 degrees) to prevent "shrouding" against the cylinder walls at lower valve lifts. Intake ports have been reshaped to work with the larger valves and higher rpm potential, as have the camshafts, with the intake cam made shorter for less weight by relocating the cam angle sensor.
Stacking the mainshafts also...
Stacking the mainshafts also permitted the engine cases to be made from two sections rather than three, cutting weight and adding strength at the same time.
The new crankshaft features...
The new crankshaft features a separate lubrication system for the connecting rod journals and the main bearing journals, with the rod bearings fed through the crankshaft end. This reduces the load on the oil pump, translating to less power loss and better durability at high rpm.
The larger bore permits the...
The larger bore permits the titanium valves to grow 1mm, with the intake now 31mm and the exhaust 25mm in diameter. With the included valve angle slightly steeper at 24.5 degrees (due to the exhaust valve angle going from 13 degrees to 12.5 degrees), the compression ratio raises incrementally from 12.5:1 to 12.8:1.
The crankshaft features redesigned oil passages, with the rod journals fed separately through the crankshaft end instead of through the main bearings. This would presumably allow lower oil pressure (and less power loss driving the oil pump) because the pump won't have to overcome as much pressure bleed and centrifugal force to feed the rod bearings at high rpm. Also reducing frictional losses is a counterbalancer with a smaller 20mm shaft bearing diameter. As is becoming increasingly common with inline four-cylinder engines, the mainshaft positioning has been stacked closer together (the crankshaft and mainshaft are now 59.7mm closer), which not only shortens the engine but also allows a two-piece (instead of three-piece as before) crankcase assembly for less weight and greater strength.