Yamaha launched the YZF-R1 after redesigning the Genesis engine to create a more compact engine by raising the gearbox input shaft and allowing the gearbox output shaft to be placed beneath it. This ‘stacked gearbox’ was followed by other manufacturers. Compacting the engine made the engine much shorter, allowing the wheelbase to be shortened. This allowed the frame design to place the weight of the engine in the frame to aid handling because of an optimized center of gravity. The swingarm could be made longer without compromising the overall wheelbase, which was a short 1,385 mm (54.5 in). Four 40 mm Keihin CV carburetors fed fuel to the engine. It had KYB upside down 41 mm front forks and 300 mm semi-floating disk brakes. The instrument panel was electrical with a self diagnosis system and digital speed readout. The exhaust system used Yamaha’s Exhaust Ultimate Power Valve (EXUP), which controlled the exhaust gas flow to maximize engine power production at all revs. This created a high powered and high torque engine. The Yamaha YZF-R6 was introduced in 1999 as the 600 cc version of the R1 super bike.