Cycle News - Archive Issues - 1990's

Another Kawasaki missle. The ZX-6R's Sho~-stroke powerplant makes impressive - and totally smooth - power. A slightly vague-feeling front end limited rider confidence at the track somewhat, though It was still the second-fastest bike around the Speedway. On the street, there was no vagueness to be found, and the accurate, stable chassis and super-smooth motor made it a pleasure to ride. T flIiIt. . . . 1'IIIlIliI-s of our 6OOa: sbootout took place IllOt OIl the tnlckbat in the paddock. As soon as each bike _ ~ to rIQl, it was ridden up the ramp into the offi· ciaI ~ ifeselu.dt dyao trailer, parked right beside the Freddie~HigIl Performance Riding School garage. o,nojet'a permanent developtnent facility is located just ~ from the Las Vegas circuit, so it didn't take long for tIiIir litaff to travel'from the office and set up their immacu1* trailer. While the newer, 200 model Dyno was recently Ia1iIlcbed by Dynojet, the trailer contains a 150 series, the molIt a>mmon version, with over 2220 relatives in use worldwide. The 150 series, finished in red, can be updated to 2oo/black apedfication. The 200 is designed to run a Windows 95-based operating system and has a hardware stack that measures atmospheric conditions SO that the dyno operator doesn't have to record and enter that info:rmation. In addition, the 200 series provides for a greater range of inputs, allowing the use of direct data acquisition while running on the Dynojet. Dynojet dynos are used to enforce "OOT class" rules in ASB, Formula USA and Canadian National class competition. Ensuring the accuracy of our comparison were two people familiar to most North American racers, Dynojet's Lawrence Bolton and Mike "Crowbar" Cory. Bolton is Dynojet's general manager for research and development of fuel-management Products, and as such is one of the first to test and tune new models when they debut. In a former life, power-hungry Bolton built and raced Canada's fastest-ever Suzuki GSX-RllQO-based superbike. After years of testing and experimentation, not much surprises Bolton, and the numbers generated by the four 600cc-class machines were within anticipated parameters. "These are typical of the same model machines that we've run previously," confirmed Bolton. Many sportbike fans, and particularly OOT-class racers, may be surprised by the somewhat low outright horsepower numbers produced on the dyno. Some magazines, notably in Britain, have shown the Kawasaki to produce 100 hp at the rear wheel, well . clear of our seemingly strong-running ZX-6R example. Bolton is careful in his comments, but concedes that "worldwide, there are quite a few preproduction bikes out there, and they often yield some very high numbers. But I think these bikes are a fair example of what a customer could expect from his bike." Of the four machines tested, the Suzuki would benefit the most from aftermarket carb adjustment. "We've had a lot of phone calls about the Suzuki, and we've spent time working on it," says Bolton. "I think the Suzuki may be the most tunable; you can get a night-and-day difference in throttle response. "All the bikes will improve with tuning - there are always gains to be found. For instance, you can get the Kawasaki to rev quicker, and respond betler to on/ off throttle work at higher rpm." Many sportbike owners soon go the pipe-and-jet-kit route, and Bolton believes that all the bikes would also respond well to the hot-fod treatment. '1rs difficult to choose one of the bikes as the best to modify," reflects Bolton. "They would all benefit, and by close to the same percentage amounts. On all of them you could get a 5-hp gain quite easily, and the bike would absolutely be more fun to ride." One of the central selling points to the Dynojet dyno system is the fact that each dyno produces nearly identical results when c...oon GSX-R600 . . . . - - - 8•.0 . . . T..... -42.8 MaxP_·90.o llliax Torq_ - 45.0 ,~ " " . :~ ~ E[. .---.=="'--i-.c·,···l:: 1 ~ :! . .~ . ," .j •.• ~ 10 zx..ea UNOOII ... .--.1M.3 .... T _~-.'A _ T.........7 _-43.8 Oynoj.. R• ...-m Inc. .. compared to another Dynojet. This makes comparison tuning fa.r easier for customers~ and attracts many top race-bike builders. Confident of his product, Bolton states that "if the Dyno is operated correctly, and there are no malfunctions of any kind, you should be able to take the same bike to 20 different Dynojet centers and get a reading within half a horsepower, easy. I'm pretty confident of that; they're really consistent." "For every Dynojet dyno that's sold, we first measure the mass of the drum (the weight that's spun by the rear wheel) on a test table. That gives us a mass number. The mass number goes into the computer program for that dyno, and for that dyno only. No two are exactly the same. We already know the bearing drag, and all of that. "But the software isn't interchangeable from Dynojet to Dynojet," cautions Bolton. "You can't swap software between identical model dynos. Our biggest problem is people swapping software" Viewing the results of the dyno runs conducted with the 600 machines on test, Bolton considers the Honda to be the best set up of the four in stock trim. Bolton bases this opinion on the "range" of the carburetion. "Due to regulations," says Bolton, "running at steady speed is usually lean. This isn't usually a problem stock. But if the bike isn't within its best range, when you put on a pipe or use bad gas, then you'll feel that surge." Colin Fraser . .... ~ ,~ " " " " .... : " " ., " :~ ~ . :: w ". ':: r ." :: ii~ •• ::f :; :1 >0- . • 7.\- .. .~ ." . '" ..........................................:...-~: :--- 2~.$.7 •• _(11'000)

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