Cycle News - Archive Issues - 2000's

Benelli Tornado 900 Superbike (Left) The th...• into-one-Into-two exhau.t system i. made by Arrow and emits a sound that I. unique in the current Woo1d Superblke paddock,The rear-mounted radiator I. al.o unique to the SBK paddock, and Is said to help the Benelll run seven to eight degrees cooler than the Ducat! and Aprilia superblke., (Right) The adjustable triple clamps 'eature eccentrics which allow the steering-head angle to be adjusted from 22.5-24.5 degree•. The fuel tank I.n't really the tank, It's the alrbox .hroud, with the real fuel cell residing below and back in between the frame .pars. jAbove) The front end of the Tomaclo ........ 43mm Ohlin. Inverted forks which gra.p a 3.5 x 16.5 Inch ...roc.....nl wheel, with 320mm B..mbo rotors and Brembo .......1 ....lIpen "king ...... of braking. 15 degrees from vertical, and a single gear-driven counterbalancer still retained in front of the crankcase, to smooth out vibration. Rosa says that the pluses of saving 3.3 pounds of rotating weight and regaining the power lost in driving this are very attractive, so the team plans to test an engine without the balance shaft quite soon. Valves are larger, now, with a pa ir of 36mm inlets (was 32mm) and 30mm exhausts (was 29mm) for each cylinder, set at a nowadays conservative 28 degrees included angle to each other, but with a steep angle of downdraught offering a linear intake 16 AUGUST 15, 2001 • cue I • design, breathing from an 18-liter sealed carbon-fiber airbox (almost 50-percent bigger in capacity than on the 10M prototype) fed by the twin 'nostril' airducts which have now been redesigned in shape, and increased in diameter. The result is that the Tornado racer is 8mm wider than the show prototype, brought on by a combination of the revised ducting and wider cylinder bores. It's still only 23mm wider than a Ducati V-twin, though. Gear drive to the new-profile twin overhead camshafts now replaces the street prototype's chain-driven DOHC, and a trio of 55mm Dell'Orto sandcast throttle bodies is fitted under SBK kit rules, to replace the die cast 53mm units which the street Tornado will wear. Similarly. the streetbike will use British-made Sagem fuel injection, but Goddard's Superbike racer employs an enginemanagement system produced by a company actually called EFI in Bologna, a car-system specialist founded by a team of ex-Marelli engineers, whose components are found on specialist models like the Lotus Elise, and_ which manufactures a sophisticated six-cylinder ECU, says Rosa, which has readily been adapted to the three-cylinder Benelli. A single external injector - rather than the two previously employed on the Sagem EFI, one below the throttle butterfly, the other centrally located outside the intake stack - is centrally located above the throttle body intake trumpet for each cylinder, though the cen- n _ _ so tral one of these is 20mm longer than the other two, to enhance midrange performance. Maximum power in the form the Benelli raced at Misano was 168 hp at the crankshaft (171 hp from a qualifying motor readied in case the team got into Superpole) at 13,000 rpm, says Rosa, with the revlimiter set at 13,200 revs. "But I'm confident we can have the . Tornado revving safely to 14,000 rpm," he says, "given the piston speeds currently commonplace in Formula One for similar-sized cylinders. However, any more than that will require the use of pneumatic valve gear, which I plan to develop for motorcycle use further down the road, if we can homologate the system okay." Instead of the oil-bath road unit fitted to the prototypes which ran at the IT a year ago, the racer now features a dry slipper clutch, complete with the road bike's side-loading, extractable, six-speed cassette-type gearbox, which Rosa says in combination with the dry clutch allows the team to change internal gear ratios in just 20 minutes, all without having to strip the engine or even remove it from the frame . "The shift mechanism is attached to the cluster, so it aII exits together on the left side, and is very accessible," he says. Still more unusual is the cooling system, which follows the limited-edition Britten V-1000 and Saxon Triumph-3 designs in featuring a rearmounted radiator behind the engine, under the seat instead of in the conventional position in front of the motor, with dedicated internal ducting to supply cool air to it from either side of the front wheel. The prototype street Tornado's pair of electric extraction fans to blow hot air out the back of the seat are missing from the racer, which, however, has a 20mmwider water radiator than a year ago, plus a separate oil radiator. Rosa says that the team has no problem getting the bike to run pretty cool, about 7-8 degrees cooler than a Ducati or Aprilia on a hot Italian summer's day at Misano. Use of the rearmounted radiator allows the engine to be placed further forward in the frame than would otherwise be the case, in turn loading up the front wheel weightwise for added grip, as well as delivering a short 1395mm wheelbase. Weight distribution is 53/47-percent frontward, says Rosa - but excess weight is the bike's main handicap at present, even though the complete engine now scales 68 kg, three kilos less than a year ago. The Benelli currently weighs 378 pounds half-dry (with oil and water, no fuel), 22 pounds over the World Superbike minimum weight, and Rosa says the key to the bike's competitiveness lies there as much as in the engine performance, so this is the main area the team will be working on in the coming weeks. In spite of that, though, Goddard made three excellent starts at Misano (race two was red-flagged once), each time passing six to eight riders into the first tum, with no wheelies in the bottom two gears - indicating that what weight there is is balanced well. Enginewise, the Benelli seemed to accelerate well at Misano, in spite of the extra kilos - only to run into a metaphorical brick wall two-thirds of the way down the main straight. But, the team is working hard on improving top-end performance, and their efforts are sure to bring eventual reward. The Tornado chassis is a modular one, with twin tubular steel frame spars pegged and glued with aircraft epoxy into a distinctive cast-alloy rear-frame section, in which the beautifully formed cast/fabricatedalloy swing arm pivots. Because of the very compact engine, the 570mm long swing arm is the longest on any Superbike, even more so than a

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