Cycle News - Archive Issues - 1990's

~ !~S~Of~~~:~~~am~~d~~ e ('IJ ~ ~ ... ~ H Q) ,..CIS Q) ..... 0.. search of the extra power the Ducati now delivers between 10-12,000 rpm, under pressure from the Kawasakis. This in tum has led Bordi and his men to concentrate on smoothing out the power delivery and making the extra power more usable, and improving engine pickup at low revs. Ducati has done this by a number of detail modifications, including for Germany fitting titanium rods to all the works engines for the first time, for better acceleration and engine response via the big reduction in reciprocating weight this offers, at the expense of substantial extra cost and reduced component life. The biggest change over the winter ,hi" m"h,o" Ro'oodo Simonetti. This is not a new idea: BRM used something similar in Fl car racing in the 1960s, combined with the obvious corollary of variable length exhaust headers, and Cosworth DFV tuners ha ve been using telescopic inlet trumpets on F-3000 race cars since midway through last year - which is presumably where Rolando got the idea from. Ducati and Cosworth tuners are juggling with the same aims : to make a relatively low-revving engine (9000 rpm n 0h ly for the DFV) deliver '?fo~e pObwer at t e top end, without sacn icing ottom end and mid-range torque. By extending the trumpet lengths, you improve torque at low revs, while shortening it gives Q) if) The factory bikes use variable intake flares which change in length some two centimeters. was to source a new Marelli ECU for the engine management system, whose double capacity allows them to use two separate EPROM chips to map the fuel injection for each cylinder individually. "Separate mapping gives a much crisper engine response and better pickup all through the range, but especially from 7-8000 rpm," says Bordi. "Basically, it resolves the problem inherent in a lengthways V-twin of always having the rear cylinder running hotter, and leaner, than the front one. Even with an EFI system, this still means certain compromises which you only resolve with programming each cylinder individually. This allows us to improve combustion noticeably, and we've also modified our .combustion chambers to take advantage of this: the 'shape is crucial to optimum performance with large bore sizes." Another factor has been the introduction of a big bore exhaust system, whose revised "spaghetti" shape has helped deliver more power, but only at the price of moving the power band 1000 revs higher up the revband, making it all the more vital to smooth out the delivery. Ducati has also done a lot of work on the airbox, which is now a one-piece sealed unit instead of the three-piece design used before, but Bordi's still not satisfied with it. "We need to pressurize it more as we have done successfully with the Supermono," he says. "It's quite difficult to do this with the existing bodywork, so we may have to wait till the arrival of the 916 to get it right. But for sure we have more power to come from this area." 22 The carbon fiber inlet trumpets on the works Ducatis are a slightly different shape than before, but not as different as the ones fitted to Falappa's best engine at Hockenheirn, which were the same variable length, telescopic trumpets used by team manager Raymond Roche in the second half of last season, designed and tern for next year. In that case, they'll pr eferabl e be able to pick the brains of their neighbors at Maranello, with whom they already have an exchange of technology, for the first Ferrari Fl engine fitted with "trornbetti telescopiche " made its debut in the Canadian GP in June. However, Rolando Simonetti's practi cal genius doesn't end there, for not only has he made his own version of the CTS slick-shifter fitted to all the works Ducatis except Falappa's ("I had help from a computer engineer to make it: it's mechanically improved over the CTS, plus it's much easier to fit and set up, and is more finely adjustable - all the things a mechanic needs, rather than a computer engineer"), he's also made his , own 'anti-telemetry' system for ens uring the op tim urn EPROM chip is fitted to the Ducati's EMS/ EFI. Used for the first time in qualifying a t Hockenheim on Falappa's number one bike, this comprises a horizontal row of 20 small lights fitted to the top of the carbon fiber tach console, which form a display module monitoring the condition of th e engine at an y point on the track, especially important at somewhere like Hockenheim where so much of the circuit is tree-lined before corning into the open stadium section. The system is operated by two sensors on the front exhaust pipe, one a lamda probe monitoring the mixture, the other the exhaust gas temperature. The lights are colorcoded : red , on the left, mean lean, orange in the center is optimum, and green on the right is rich. The rider must check the reading and report back to the team, who change the EPROM if necessary. "For the first time, the rider has con- The 20 smaIllighls monitor the condition of the engine at any point on the track. better top end power. The Simonetti system works centrifugally off the crank, via an electric motor which raises and lowers the trumpets via cables , according to engine revs, over a range of 20 mm. However, the need to fit a thermostat at both Brands (because of the British springtime) and Hockenheim (because of the long straights) to bring the engine up to optimum 700 water temperature, robbed Rolando of space to fit the electric motor, so the variable trumpets stayed on the bike, but were not connected. However, the potential benefits for all Ducati users of such a system - especially one that's electronically rather than mechanically controlled, perhaps as part of the EFl 's engine management system - have been recognized by the factory, and Massimo Bordi admits that Ducati have begun work on their own, more high-tech sys- trol over the engine management system, not the other way round," said Falappa, only partly in jest. "Basically, we will use it to get the best setting at the start of each session, and in the race day warmup," Simonetti said. "I don't pretend it's as sophisticated as a full telemetry system, but it's a lot cheaper and also quicker: instead of downloading the data from the on-board computer and analyzing it, which takes time if you don 't have a real time telemetry, as only the very richest 500cc GP teams do, we just ask the rider for his report after a couple of laps, then we can make the necessary change in time to take full advantage from it in the same session." The next step is obviously to revert to the three-post tion handlebar swi tch Ducati experimented with two years ago, to permit the rider to switch between different EPROM chips already installed in the ECU. Ducati has concentrated on refining the "otto valvole" engine this season, rather than paying much attention to updating the obsolescent 888 chassis. Adding weight to meet the new 319- . pound weight limit has enabled them to beef up some key areas . Though , notably the much meatier lower triple clamp (th ey're st ill using the smaller 42mm Ohlins fork , albeit a new version) , a bigger fuel pump and so forth . There's a lot less titanium around than last year - exhausts are all steel, for example - but the bikes are still replete with carbon fiber goodies which the Italians are able to source at reasonable cos t, thanks to th eir Sloven ian -based suppli er. At 323 po u n ds the w orks bikes a re the couple of pounds over the minimum weight th a t the wid e var iation in "official" scales from country to country dictates, 11 pound s up from last season - but only when fitted with the full works motor which is evidently replete with unrevealed weight-saving tricks. Fogarty was well off the pace in Friday'S un timed practice at Hockenheim, before mechanic Tony Bass fitted the fresh "pompone" engine that had just arrived from Bologna, ready for timed qualifying. "I can't believe how much lighter it was to pick up than the hack engine," he said after completing the swap. "There must be a good five kilos (11 pounds) difference in weight between the two, and it's all inside - the two look almost the same externally, and the trick motor doesn't even have a carbon clutch cover." Ducati engineers confirm a lot of work has gone into lightening internals: hollow camshafts, drilled gears and such things one can only guess at, though. The Ducatis look subtly different from last season - apart from still very red - with the late-type fairing homologated midway through last season now joined by a different shape seat and fuel tank, entirely for cosmetic purposes to help stimulate road bike sales. Close attention ha s been paid to airflow, though, with fully sea le d carbon cladding around the engine and radiator to prevent any high pressure zones being fanned inside the fairing . The chassi s is essentially unchanged, with the same geometry as last year , but a curved front upper tube beh ind the steering head, again for cosm etic reasons, to replace the two-piece welded section from before, and a wider swingarm to accommodate the new 6.25-inch wheel. The Ohlins rear shock has been improved quite a bit, says Bordi; Ducati are still sticking with the Swedish suspension for superbike racing, in spite of their growing collaboration with Showa on their street range and af500cc GP level with Cagiva. All the works Ducatis now use Brembos new 290mm carbon discs, invariably shrouded, rather than the steel, steel /carbon cocktail or 320mm U.s.-made CAT carbon discs thatPolen used last season. The differential size compared to the 320mm steel d iscs used for the rain isn 't a problem, says Team Grottini tuner Pietro Gianesin: "We can change the wh eels and alter the location of the calipers in four minutes," he claims. Actually, four minutes, 12 seconds after it started raining on the wann-up lap of the first race at Brands, according to my stopwatch. Only as the season progresses will we see if Ducati's gamble in trying to win a fourth straight title with the final version of the 888 pays off. Some vintage racer. CN

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