|
Suzuki
GSXR 600 and 750 Supersport Setup Tips Yoshimura brought the AMA 750cc Superbike Championship to Suzuki in 1999 with Aaron Yates in the saddle. For the 2000 AMA race season the riders are again Aaron Yates, together with Jason Pridmore, both in the Superbike class and in the 600 Supersport Class. In 1999 Suzuki made Team Chpparal Suzuki it's designated 750cc Supersport team, and their rider Top Kipp pulled off the 750cc Support Champioship title with the GSXR 750, which at present is the best showroom production bike in the class with lightweight, good handling chassis and powerful fuel injected engine. Legendary former 250cc World Champion and tuner Kel Carruthers is the roadracing team manager at Chaparral Suzuki. And Yoshimua R&D is the team's product sponsor for the majority of their performce products. For the purpose of this tech feature we will just deal with the Yoshimura and Chaparral Supersport GSXRs, since the tuning modifications allowed in this class are limited by the AMA rules, and similar to what most street riders and amateur racers will make to their bikes. We spoke with both Don Sakakura and Kel Caruthers to find out what they do to their team race bikes. |
|
ENGINE
MODIFICATIONS If you're on a tight budget you might want to opt for a lower priced Steel Duplex System from Yoshimura at about half the price. It weighs in around 12 pounds and offers the same power gain as the Titanium Duplex System, but the additional cost for the Ti Exhaust's weight savings is worth it, particularly if you're racing. All of Yoshimura's high end Duplex Exhaust systems are extensively tested to produce the best possible power for the 600 and 750 GSXRs, and they are the exact same Systems the two teams use in Supersport, so we really wouldn't recommend a lower priced non Duplex system, particularly from another American exhaust pipe manufacturer. However, the European exhaust manufacturer Akrapovic also produces excellent race systems as used on the winning factory Corona Suzuki's in World Championship Supersport and Superbike. But they are priced similarly high to the Yoshimura Duplex. Kel Carruthers then points out the only other internal engine modifications they are allowed in AMA Supersport is careful reworking and blending of the valve seats in the heads for maxium flow. Plus hours spent in the parts warehouse at American Suzuki carefully measuring and selecting production parts like heads and cylinders that are at the far end of approved production tollerances for a slight advantage in increased compression or reduced friction. Advantages a non factory team will never have. IGNITION
and INDUCTION RECALIBRATION Besides rejetting, the other trick to making more horsepower in Supersport is increasing engine RPM, which is limited for reliability by the GSXR's stock ignition module. Suzuki offers an optional race ignition module with a higher RPM limit which is a must-have for Supersport racing, but not very practical for the street. You can purchase this Race Ignition Module which offers no other advantage but a higher RPM cutoff point, either through your local Suzuki dealer or from Yoshimura. The GSXR 750 now uses electronic fuel injection for induction, so conventional jetting changes to match our racing exhaust system is a thing of the past. Electronic engine management is the future and Suzuki offers its Advanced Fuel Management Adjuster (black box) for the GSXR750, also available through Suzuki dealers or from Yoshimura. We asked Kel what he uses on the Chaparral GSXR 750s and he said the Suzuki Advanced Fuel Management Adjuster is limited in only offering only 3 fixed programed settings for fuel and rpm increases. For their Supersport GSXR 750s they use the Dyno Jet Power Commander ignition system, which is somewhat programable with external buttons, and fully programable from a laptop PC computer to adjust the fuel injection's fuel flow, the ignition's advance curve and RPM cutoff limit. For a race team in Superbike or Supersport with access to race track testing and a dyno to measure tuning adjustements the Power Commander is the hot ticket. But for a street ridden GSXR the Suzuki AFMA might be a more practical and affordable choice. |
HANDLING
Up front with the production Kayaba USD forks, Kel did admit they went inside the forks to play with the valving internals, but it isn't a service they offer to the public. But for most street riders the stock fork's external adjustments and a change to good quality suspension fluid will offer all that is really needed for any sportriding application. Once on the racetrack you might want to pay for the services of an experienced suspension tuner like Jim Lindmann of LE race Suspension, Stig Pettersson of Ohlins PPS, or Dwyane Jones. OTHER
GOODIES YOSHIMURA
PARTS Suzuki
GSX-R 600 Yoshimura
R&D of America Dynojet Research / Jetting Kits, PPS Suspension
/ Ohlins (714) 630.4777 |
|
At Right: Aaron Yates' 1999 AMA National Championship winnning Yoshimura Suzuki GSXR Superbikefeaturing the Titanium Duplex Exhaust System, Crash Guards, Billet Raised Foot Peg Set. Paddock
Garage Index
|
