Cycle News - Archive Issues - 2000's

liter R1/FireBlade rivals - and even on one memorable occasion outsped Chili on his race-developed old-type Superbike! - says it all. The chance of an exclusive ride aboard the golden oldie Chili machine at the Alstare Corona team's first post-season test session at Almeria underlined several things. One, ongoing development by Suzuki's R&D engineers, and Alstare Corona's, in the team's impressive in-house facilities at their Liege base, had refined the old-model fuel-injected GSXR750 to an impressive degree that was almost unthinkable three years ago, before the Belgian team took over the Japanese factory's fourstroke race operations at the world level - while at the same time leaving room for improvement on the new model. Two, that very same new model is incredibly impressive even in barely breathed-on Superstock spec - a fact I had firsthand proof of myself at Almeria during the 20 or so laps I spent dialing myself in on what is a new - and very technical - Spanish circuit. The new GSX-R750 is infinitely more aerodynamic than the old one, as well as oozing with potential for this season's Superbike racing. Then it was my tum to experience the benchmark provided by the ultimate evolution of the old-style 750 Suzuki, which in its final developed form produces 172 hp at the gearbox at 14,100 rpm, and is revlimited to 14,400 rpm. This is rather conservative by the standards of its four-cylinder brethren on the Superbike grid, with the R7 Yamaha (with identical 72 x 48 mm engine dimensions) and the shorter-stroke ZX-7RR Kawasaki both revving to 15,500 rpm, reliably. Indeed, Suzuki did produce an Eva version of the GSX-R750 with modified internals at Brands Hatch in August, which was redlined at 15,400 rpm and had extra power up high but Chili was still getting over his broken collarbone sustained when Noriyuki Haga brought him down at Misano, so opted not to test it in order not to rest the injury. Thus, it was returned to Japan unraced, though Ryo did apparently rUQ it in the Japanese Championship with some success, as part of the R&D program for this season. But the lower-revving motor used by Alstare Corona has been quite reliable, except for a couple of high-profile engine failures caused by broken valve retainers - a problem which the factory apparently managed to cure. That huge radiator is there for a purpose, though: the Alstare dyno reveals a 12 hp power drop if the water temp rises from 176 to 194 degrees Fahrenheit, as it would for example at Laguna Sec a last July, without that massive radiator. It earns its keep. For 2000 there were many detail improvements to the engine specifications, as part of the ongoing evolution of the bike that had allowed Suzuki to join the World Superbike circle of winners in 1999. Though retaining chain drive to the double overhead camshafts, rather than the gear-drive option previously used on works Suzukis, new 2000 World Superbike parts included a lighter crank, lightweight three-ring pistons running in chrome bores, revised camshafts, titanium valves and connecting rods, and a carefully worked-on cylinder head (with different porting and ultra-hard beryllium-copper valve seats) delivering a higher 14:1 compression - all testament to Suzuki's dedicated in-house development, as well as an all-new Arrow exhaust employing a narrower bore than the Akrapovic used last season, in order to enhance gas velocity. This too was initially made out of titanium, before the Italian company produced a complete system at Brands in October that was over three pounds lighter still than the titanium pipe, made from an exotic alloy used on the world champion Fl Ferraris' exhausts called Inconel, which is heat resistant and strong enough to be used in just O.4mm wall thickness, instead of the titanium pipe's 0.8mm. The Nippondenso EFI and engine management system was also improved, to allow easier setup rather than more power - correct mapping is crucial on the Suzuki, to get it performing at its best. I had a graphic illustration of that at Almeria, as I struggled to tame a so-potent piece of hardware whose aggressive throttle response and snatchy pickup from a closed throttle made it a real handful on such a tight, technical circuit, where you have to play the twistgrip with the virtuosity of a violinist in order to keep the rubber side down and the bike on track. Mind you, I was in good company - for on our second day the Spanish sunshine was replaced by overcast conditions punctuated by rain that would not stay on the plain. Chambon refused pointblank to ride the GSX-R750 Superbike in damp conditions: "This is such a handful the way it's set up at present - I don't know how Chili rides it so brilliantly and wins races in the rain with such a jerky throttle response, that gives you a thousand rpm you don't want as soon as you think about opening the gas!" Yes, Stef, that about says it all. I reckon I'll retire to the truck and write up my notes. IAbove left) Last year's Corona Suzuki was basically a five-year-old motorcycle, refined by both the Suzuki R&D department In .Iapan and by the Corona crew In Liege, Belgium. IAbove right) Suzuki has braced up the stock frame with a strvt above the cylinder head to tie the two spal'S together, resulting In a stiff chassis. (Right) Chili uses Showa suspension on hi. Gixxer, Dunlop tires and a great deal of experience and talent to win Wortd Superblke races. To be fair, there was a good reason for this - as I had reason to suspect, having already ridden the Suzuki in fuel-injected form last season, and not found the engine response to be even as bad as the R7 Yamaha, hitherto the benchmark for bad behavior in terms of brusque pickup from a closed throttle. "We can fix this," insisted Alberto Mora, Chili's faithful race engineer whose untiring efforts far away from the limelight have played such a vital role in making the Italian star who's everyone's favorite (well, except Mr. Fogarty's, perhaps) into such a key player in World Superbike racing. "But only by altering the fuel mapping, which is critical for every circuit, and needs to be dialed in properly at every race. But the problem for you and Stef is that the Japanese engineer who is the only one who can take care of that couldn't come here to Almeria because he's back home working on the new engine. Sorry! We've made it a little better by slightly altering the fuel supply - but this is something we always have to deal with on a Friday morning at the start of practice for each race." Okay, I'll have to live with it, I guess - but it sure makes it hard to ride a twisty track like Almeria, where you have to brake deep into the apex of a bend, get the bike turned, then power out - there's not a lot of places cycle where you can keep up much turn speed on a bike this powerful. And this despite the fact that the chassis setup is definitely nicer than I remember it being from a year ago, and it changes direction surprisingly easily for an in-line four that felt quite a bit bulkier than the new-model Superstock I'd just been riding. The snatchy pickup was the worst in the bottom two gears - it wasn't nearly as bad in third, presumably as a function of the engine management mapping, so the trick then became to see how many places you could get away with holding third gear, for a nicer throttle response that didn't threaten to unhook the back wheel with the bike leaned over. That's when I discovered how well the Suzuki engine picks up low down, driving cleanly out of a turn from just 7500 rpm - Mora says he's seen Chili run it as low as 6800 rpm, and he usually uses 8000-9000 rpm midturn. The engine comes on stronger n __ • • FEBRUARY 21,2001 19

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