While the engine's power advantage was seen on the faster tracks such as Suzuka (which is actually owned by Honda), Assen, Spa and Paul Ricard, on tighter tracks such as Jarama and Jerez it was off the pace due to its handling. More improvements gave the 1989 NSR500 upwards of at 12,000 rpm — essentially doubling the output of the 1966 Honda RC181 Grand Prix four-stroke. Capable of well over , the 1989 bikes had more top speed and acceleration than anything else on the track. To contain all that muscle, the stiffer, twin-spar aluminum chassis used a curved, gull-wing-type swingarm to accommodate more efficient expansion chambers. The 1989 bike was also the first Grand Prix bike to incorporate an early form of a quick shifter, although it only allowed clutchless no lift upshifts. The result was an unforgiving, but brutally fast, package that earned Honda a fourth 500 cc World Championship in 1989 thanks to Eddie Lawson who had joined the factory backed Rothmans team alongside Gardner and young Australian Mick Doohan. 1990–1998 Though the 499 cc V-4 could produce more than , chassis development, sophisticated engine management and an Australian named Mick Doohan made the NSR500 a legend in the 1990s. Extensive testing in 1991 led to a new aluminum chassis patterned on the successful RVF750 endurance racer. Honda unveiled a revolutionary idea with a 1992 V4 that was timed to fire all four cylinders within 65-70 degrees of crankshaft rotation — the so-called "Big-Bang" engine. Along with a balance shaft that neutralized the single crankshaft engine's gyroscopic effects, the 1992 NSR500 was a breakthrough. Emphasizing acceleration over sheer speed, Doohan used this engine to win five of the first seven 500 Grand Prix races of 1992. Although a badly broken leg denied Doohan's bid for the 1992 World Championship, he would not be denied for long. Beginning in 1994, Doohan and the NSR500 won five consecutive 500 cc World Championships. Winning 12 of 15 races in 1997, he broke a single-season win record that was set in 1972. Combining for 54 total 500 Grand Prix wins, no man and machine in modern history had dominated the 500 World Championship so thoroughly. From around 1997, the NSR500 again featured the older "Screamer" engine in some factory racers, with Mick Doohan preferring the higher outright power of this design despite it being much more difficult to harness. 1999–2002 Constant