Chief engineer Itoh-san does a fine job of explaining the concept during the technical briefing, but it's still not finding traction in my simple squid-brain. Let me get this straight: You push a button with your thumb and it decreases power output? Detunes on demand? Why would you ever want to do that?
Later in the day, after a few dozen laps around Australia's Phillip Island Grand Prix circuit on the all-new 2007 Suzuki GSX-R1000, I could almost understand the inclination to soften the power output. With a freer-breathing head and more aggressive cams that give the newest Alpha Gixxer an utterly ferocious high-rpm blast, this is the nastiest GSX-R ever built. Intimidating, even, especially in Phillip Island's Turn 12 where, once you finally dislodge your testicles from your stomach and find the courage to stay in the throttle all the way through, you will basically liquefy the rear Bridgestone Battlax for the duration of third gear. So tell me again, which button do you push to slow this sucker down?
After two decades exciting us with ever-increasing horsepower numbers, this latest GSX-R asks us instead to embrace the concept of less power on demand using something the acronym-happy Japanese have dubbed S-DMS, or Suzuki Drive Mode Selector. The key to getting your head around this idea is not to think of it as something that makes the bike slower, but to think of it as something that makes the bike easier to ride faster. S-DMS is essentially a passive traction-control system intended to make this bad beastie easier to manage in less-than-optimal riding conditions by allowing you to select from one of three preset power maps. Welcome to the next revolution in performance! Suzuki engineers candidly state that modern sportbikes make too much power for most riders in most situations, and the next frontier will be to harness that power and make it usable with electronic controls. The '07 GSX-R1000 is leading that charge.
The S-DMS system offers a choice between three power output levels: A-mode is unrestricted maximum power output; B-mode significantly softens throttle response until the throttle position reaches 97 percent open, at which point it merges with the A-mode map for unrestricted power delivery in the upper rev range; C-mode reduces power output by roughly 35 percent at any throttle opening. Make sense?
S-DMS is operated via two buttons (one up, one down) located on the right-hand control housing, sandwiched between the kill switch and starter button. Pressing these buttons allows you to toggle up or down between different maps on the fly. The S-DMS is driven by a new, 32-byte ECU that controls power output according to a series of complex (and instantaneous) calculations based on throttle position and engine rpm and alters either the ignition timing, the rate at which the secondary throttle valves open or both, depending on which power setting you selected. Illuminated letters beside the gear indicator on the tachometer face tell you what setting you are in. If you choose not to activate the S-DMS system (activation requires depressing either the up or down button for 2 seconds anytime after the bike is started), it automatically defaults to full-power mode.
In simplest terms, think of the differences between the A, B and C settings as the differences between the 1000cc, 750cc and 600cc GSX-Rs. Suzuki's engineers claim maximum output in C-mode is approximately 120 horsepower, roughly identical to that of a GSX-R600. B-mode produces power roughly equivalent to a GSX-R750 at anything less than full-throttle. Can't choose among a GSX-R600, 750 or 1000? With S-DMS, you can have all three bikes in one.
Offering a method to mediate the power of this latest-generation Gixxer is not unwise. The cylinder head has been revised with less-restrictive intake ports (enlarged 10 percent) and exhaust ports (20 percent larger than before), and the exhaust valves have grown 2mm (to 26mm) to better pass spent gases. New 12-hole, showerhead fuel-injectors are now positioned at a steeper, 30-degree angle to shoot more directly into the intake tracts, and a new dual exhaust flows nearly twice as much volume as the single can on the GSX-R600 and 750 finishes the job. These tweaks add up to a respectable 4 percent increase to a claimed 185 horsepower, with peak power now arriving at 12,000 rpm-1000 rpm higher than last year.
In addition to the power peak's upward migration, the dyno trace shown at the launch displayed a slight loss of midrange power, as one might expect with the move to bigger valves and more aggressive cams. The engineers said this was intentional, as the superior midrange of the last-generation bike made it more difficult to apply full power mid-corner under racing conditions. Interestingly, the strong midrange power of last season's GSX-R1000 was a welcome contrast to the more top end-biased competition in Yamaha's YZF-R1 and Kawasaki's ZX-10R and one of the main reasons why we preferred it as a streetbike. Though it was difficult to judge on such a fast track as Phillip Island where one seems to always be at the top of the rev range, it will be interesting to see how this new power characteristic will affect our opinion of the GSX-R on the street.