Superbike Screts
Superbike Screts
Digging below the FP1'S sexy green bodywork
KEVIN CAMERON
THE FOGGY-PETRONAS FP1 MAY be crucial to the future of World Superbike. Without it-and with Honda out-there is only Ducati in the first rank, opposed by teams of lesser reputation.
Malaysian oil company Petronas has reportedly allocated $50 million for the development and operation of the new Superbike. Its threecylinder engine was designed by project engineers Luca Guerciotti and Zaimizi Hamdani, with oversight by veteran Honda/Ferrari/
Sauber Formula One engineer Osamu Goto. When Goto first came to Ferrari from Honda, it was rumored that he was in some sense a “gift” from the Japanese, a means of revitalizing F-l auto racing. Trends at Ferrari are seen in the Petronas Triple’s radial valves. All valve stems (four per cylinder) tilt slightly away from the central sparkplug, concentrating charge there. The nearer the main mass of charge to the point of ignition, the faster combustion will be.
While the original 990cc MotoGP Three measured
93.0 x 47.5mm, for a bore/stroke ratio of 1.96:1, the FP1 is
88.0 x 49.3, a ratio of 1.78:1. This splits the difference between F-l car practice and the 1.6:1 ratio seen in today’s production sportbike engines. Cars, with their wide tires, better tolerate an abrupt powerband than can bikes. Extreme F-l bore/stroke makes power on top, but must trade away compression ratio to achieve the flame speed to do it.
The FP1, with its faster-burning, lower-aspect-ratio chamber, may deliver a fuller powerband through its 14:1 compression. Claimed (or expected) power is 185 at 13,500 rpm, with peak torque of 78 ft.-lbs. at 11,000.
Converting these into BMEP, or net strokeaveraged combustion pressure, we get 197 and 215 psi, respectively-very high but definitely achievable numbers that characterize fully developed race engines.
Peak-power rpm gives a moderate
piston speed of 4400 feet per minute and peak piston acceleration of 6200 times the force of gravity. Today, these figures are almost conservative. Aprilia’s WSB engine reaches for 6000 fpm and acceleration touches 7500 g. All this indicates that the FP1 has room for development.
Which it will need: In Mr. Forsyth’s preceding text, he notes some power-delivery problems, especially accelerating away from slow comers. The FP1 crew tells him a quick fix is forthcoming via ignition/injection remapping. Upbeat attitude is fine, but “typing” (software) doesn’t always fix this problem. The bike carries an MF4M fuel system from the respected maker Marelli, with dualinjector 55mm throttle bodies operating at 74 psi, but injection may not be the issue. What if, in the rpm band used for most comer launches, the cams and pipe are leaving the cylinders mostly full of exhaust gas?
Chassis and suspension are what you would expect-twin aluminum beams and premium components, including “Foggy-O.Z.” six-spoke wheels, Brembo radiale calipers and Öhlins suspenders. But attempts by Cycle World to obtain fairing-off photos and information have been parried. Such secrecy is comic. In my experience, the tighter the security, the fewer secrets a team actually has. Think of the Harley VR1000!
This team has solid assets besides Petronas and Sauber support. It is rare for top riders to be directly involved in prototype development, but here Troy Corser-not some corps of nameless test riders-is at work. Engineers shuttle back and forth between engine-builder Eskil Suter’s shop and Sauber, in charge of parts production.
Two development schemes exist in this business. One is Ducati’s, the small, efficient group of race-experienced engineers, riders and technicians who stay close to their work. The other is the Corporate Giant Method, which substitutes numbers and procedures for experience, and often uses racing as a training scheme for novice engineers. Both have worked, but based upon WSB titles won, which do you pick? Foggy-Petronas, though backed by multimillions, has picked small and efficient.
Having confidence to put a journalist on the FP1 indicates the team has achieved predictable parts life. Improved parts were under test as the article was being written. That will continue as long as the program itself, for a racing motorcycle is not a thing, it is a process. Who grows fastest, goes fastest. □
