Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128407
Did I guess right, teacher? "I can't tell you exactly what we've done, but you're close," says Yamaha team manager Maio Meregalli. "The riders complained early on about the aggressive throttle response, plus, on top of that, we weren't allowed by the FIM to do what our Virgin colleagues did in Britain to improve traction out of a turn, and anyway, the big-bang engine's closed-up firing order works okay on tight tracks like the British ones, or Valencia; but on bigger circuits like here or Assen, it affects performance because it gives less power at higher revs. So what we've done is try to make a compromise, both mechanically and electronically." It seems likely that what this entails is rephasing two of the four throttle butterflies, so that when you twist the wrist from a closed throttle, only one pair opens while the other lags behind, only catching up at that 6-7,OOO-rpm threshold, with the ECU varying the degree to which they're out of sync with each other, depending on the rpm, the gear selected, and the throttle opening. Once all four butterflies are wide open, the process is eliminated because the flow is equalized; but at lower revs it's more noticeable, and effective. Clever - and whatever they've done, it definitely seemed to work in giving enhanced drive out of the ,low first two chicanes at Monza, a fact con. 'led by ex-12Scc World Champion Alex Gramigni, who won the Italian Superbike title on his kitted privateer RI last season, and he says the Haga bike hooks up much better out of these very turns than his own Yamaha does, without this trick system. For this is also effectively a form of traction control, albeit working mechanically on the throttle rather than electronically on the ignition andlor fuel supply - a fact that concords with Haga's expressed desire not to have such a system on the bike. "This is my traction-control-best system it means Iam in control, not computed" says Nori-chan expressively, twisting his throttle wrist and flapping his clutch fingers. MeregaJli isn't so sure; "On tracks with poor grip, for sure, traction control would be an advantage," he says, "and also when the tire is worn. But we don't have the time, the resources or the facilities to develop this - that's why we hope the factory will support us directly in future, especially since next season we will use the same ECU as Rossi has on his MI, the Magneti Marelli Marvel 6. This year we are using the MFS, which is the same we had on our Supersport R6 it's okay for development, but the other one will offer a much greater choice of solutions." However, that may not provide the fix for what appears to be the Yamaha's biggest handicap at present, which is the layered nature of its power delivery. This is really noticeable compared to the Corona Suzuki's fabulously linear but still potent power curve, against which the Yamaha's motor is still quite powerful, but much less ridable. There's less drive at lower revs than the GSX-R I000 - or indeed the PSG-I Kawasaki Itested earlier in the year - meaning that on the RI, I had to work hard at keeping up momentum in those two slower chicanes, or else the engine would bog if I let the revs drop too low. At first, I even found myself clutching it up into the powerband exiting that slow first turn 'til 1 had enough confidence in the front end to crank it on its side and maintain momentum. "Okay" - I hear you say - "but this is a racer, so you must expect keep it rewing." To which the reply is that there are several turns on racetracks around the world (Monza's first two chicanes, Magny-Cours' array of hairpins, Valencia's turn two - need I go on?) where you can lose far more time with a bike that won't drive well from low revs (i.e., 6000 rpm upwards) than you'll ever be able to make up on faster bends or down the straight. But then on the Yamaha, the engine takes off at the 8S00-rpm mark, with a fat midrange surge of power, between there and 12,SOO revs, that had the rear Pirelli spinning up after four or five laps of hard use - in spite of which it'd grip well enough to deliver repeat leaned-over power wheelies exiting the Ascari chicane for the run down to the Parabolica. Before I worked out that, I needed to lever my weight forward by pushing on the footrests to counter this. Not easy to do while you're still hanging halfway off the bike, but I got it figured out well enough in the end to post a qualifying time for the World Superbike race that will be held there in May this year, and that was quite satisfying on race tires. Or rather, the ones they used back then for the moment. But at around 12,SOO rpm, the RI's power curve starts to flatten out, and while absolute power does keep bUilding more slowly to the soft-action 14,200-rpm rev-limiter, there doesn't always seem too much point in flirting with that, so by the time that