BEAST OF BOLOGNA
Ducati unleashes the V-4 Panigale superbike
Despite the obvious reason for this story’s title, I chose it for the Panigale V-4’s parallel with Fiat’s 28-liter S.76 racing car of 1910—the 300 hp “Beast of Turin.” Dorna CEO Carmelo Ezpeleta said a few years ago, “Liter-bikes are finished, and they’re not coming back,” referring to when sportbike sales collapsed during the Great Recession of 2008–09. Are liter-bikes now mythic giants from a past age, destined like Fiat’s S.76 to be replaced by smaller, nimbler machines? I put this question to Claudio Domenicali, the admired and respected CEO of Ducati, a man whose ability has carried him up through engineering, racing, and R&D to the highest management level.
He answered that Ducati’s success is driven by the company’s ability to bring the leading edge of motorcycling to its customers. Ducati must therefore continue to satisfy their expectation that the company will remain the “arrow of progress.” The focus of V-4-engine development has been to combine great power with rideability. This is in contrast to the traditional sportbike torque curve, which is weak at the bottom and even in midrange, rising steeply at higher rpm.
The V-4’s maximum torque is 92 pound-feet, and lies in a broad flat zone from 9,000 to 11,700 rpm. The curve is an arc of a circle with a broad, flat on its top. Contributing to this flat torque is a motor-driven dual-length intake system. When the four bellmouth extensions are lifted, intake length becomes 25mm shorter. Each oval intake port is equivalent to a 52mm (2.05 inches) round hole. Airbox volume is a large 14 liters. Each pair of throttles has its own control motor, and throttle bodies are barely an inch high.
Bologna’s twins have advanced the state of motorcycling over four decades, but pressure for change has forced the desmodromic-valve V-4 Stradale engine into
existence. Ducati’s first sea change was from sporty singles to Taglioni’s V-twins, driven by the vibration and limited power of one cylinder. In the Panigale 1299 twin, cylinder bore became a tremendous 116mm (more than 4-9/16 inches), stretching the limits of high-speed combustion. This now forces a second great change— adoption of four cylinders to reset bore to 81mm to put Ducati at the top of superbike performance worldwide.
The new V-4 at 81 x 53.5mm bore and stroke displaces 1,102.7cc, but a 1,000cc version for World Superbike will be produced. Like the twins before it, the V-4’s V-angle is 90 degrees, making a balance shaft unnecessary. With the two crankpins of its three-main-bearing forged-steel crankshaft offset at 70 degrees and with cylinders firing as 90-degree pairs, engine sound remains close to that of the twins. Ducati calls this “twin pulse” because each sound pulse is actually two cylinders firing 90 degrees apart. Compression ratio is 14:1, protected by detonation sensor. The springless desmodromic machinery driving this engine’s 16 valves is tightly packed in its heads, and valve-clearance service intervals are 15,000 miles.
Although horsepower is only one element of performance, everyone wants the number: 214 hp at 13,000 rpm or, with the closed-circuit-only Akrapovic exhaust, 226 hp and a 414-pound weight. This engine is not working hard at peak power, if we consider that maximum piston acceleration is 6,350 G at 13,000 rpm—less than in stock 600 Supersport engines of the past decade.
Like Ducati’s present 81 x 48.5mm Motogp V-4, this engine rotates “backward” (opposite the wheels) to reduce resistance to direction changing by causing wheel and crank precession forces to partially cancel out each other. As an added benefit, it also reduces wheelie and rear-lift tendencies. In many reverse rotators of the past, this has been accomplished with a jackshaft, but in this V-4, an idler gear does the job.
As in the Panigale V-twin before it, the V-4’s remarkably light 142-pound engine is a structural chassis member. But as necessity has forced upon all builders, the V-4’s chassis aims for an optimum middle ground between extremes. The V-twin Panigale’s monocoque airbox/steering head chassis was initially too stiff, but the long-serving and effective steel-tube trellis chassis was no longer stiff enough for the rising grip of modern tires.
As GP engineer Mike Sinclair once put it, “Something must protect the grip of the tires from the inertia of the engine.” This isn’t hard to understand: Leaned over in a corner, when a tire receives a bump impact, something’s got to give—if there’s no flex in the chassis, then tire grip itself must give. Then you have a control problem.
Protective flexible chassis elements are now in place: Up front it is four struts joining the steering-head box to four points on the engine. In the rear, it is bladelike vertical elements coupling the otherwise rigid single-sided swingarm to pivot lugs on the back of the gearbox. When I asked Stefano Strappazon, vehicle project manager, about the design of this new forward frame, he said it must provide three basics: bending stiffness sufficient to handle braking force, torsional stiffness to keep the wheels in plane (preventing the upset of “flex-steer”), and lateral flexibility in a desired range of values, to provide rider “feel” and sustain tire hookup at high lean angles and on rough surfaces.
In addition, weight must be controlled and manufacturability guaranteed. Computers now use algorithms that calculate and adjust stiffness with relation to part dimensions at high speed, slightly changing the design at each step. In this way, a design can be made to converge on an optimal solution. The V-4’s forward-frame solution weighs 9.2 pounds.
In the past, the length of V-twin engines has made modern mass-forward weight distribution hard to achieve. The 1098 S, for example, was an even 50/50 front to rear, while the 1299 Panigale went to 53/47. Now in the more-compact V-4 (consider the 1299’s stroke of 60.8mm with the V-4’s 53.5), it becomes the sought-after 54.5/45.5. Central to achieving this is engine orientation in the chassis: In the first V-twins of the romantic beveldrive era, the front cylinder was raised only 15 degrees from horizontal, but in the V-4, that angle is 42 degrees.
The engine embodies the horizontally split crankcase originally planned by ottovalvole creator Massimo Bordi, who designed the original four-valve-per-cylinder 851 V-twin. The four hard-plated closed-deck cylinders are
die-cast in unit with the upper crankcase. This is not an adaptation from the Motogp engine but is designed for modern serial production. In the Motogp engine, the four camshafts are driven by spur gears, but for production, the cam drive becomes silent chains. Steel chains have replaced the rubber-toothed belts used on past Ducati V-twins because increased durability is required to give both short valve timings (to boost low and midrange torque) and high valve lift (to preserve top-end power).
A major goal of any production engine is rideability, so the V-4’s cams have a moderate 26 degrees of symmetrical overlap. In general, the longer the overlap is made in the interest of increasing power, the fussier the engine’s behavior.
Steel connecting rods are side by side on the two crankpins, compelling the cylinder blocks to be offset as well, with the rear cylinders to the right. The cam drive of the rear bank is on the left, and that of the front bank on the right. So that centrifugal force will help rather than hinder oil delivery to the crankpins—oil is fed into the end of the crank rather than bled off the main bearings as is usual in auto engines. There are four oil pumps: one pressure, three scavenge. One scavenge pump returns oil from the heads while the other two pull from the two crank chambers, all of which return to a deep underengine sump.
Pistons are hard anodized from the piston ring belt upward. This not only discourages transfer of aluminum to the top ring from the bottom of its groove, but it also protects the piston crown from detonation’s tiny teeth. These are modern nine-cavity forgings with short narrow skirts, making them ultrastrong and also light.
The forward position of the engine allows swingarm
length to increase to 23.6 inches (3 inches longer than the 1199 unit, incidentally, but the same weight). Part of what makes this length possible is tucking the gearbox shafts on a slant, closely under the rear cylinders. Swingarm weight is 11.2 pounds. Steering geometry is 24.5 degrees rake and 3.94 inches trail, on a wheelbase of 57.8 inches (that’s 1.25 inches longer than the 1299).
Brake calipers are Brembo Monoblock Stylema 4.30, an evolution of the previously king M50 units, which are 2.5 ounces lighter but equally stiff. They feature the current trend toward reduced fluid volume and increased coolingair access (thanks in part to their hollow central bridge). Front-brake discs are 330mm in diameter. Wheels on the base bike are cast aluminum, and the starting battery is lead acid (located just behind the steering head).
The S version, as well as the Speciale (limited edition of 1,500 machines), incorporates an Öhlins NIX30 fork and TTX36 shock plus forged magnesium wheels (saving 2.2 pounds of crucial rotating weight) and a Lithium-ion battery. The Speciale gets an all-titanium Akrapovic titanium exhaust, plus carbon and billet special parts (billet fork crown, hinged clip-ons, articulated levers, carbon fenders, plus special attention to detail).
When the 1098 program was initiated, Domenicali had recently become R&D director. He announced, “For every part, you must think about the weight and about the performance—no compromises.” One of the big changes in engines in the 21st century has been the application of casting methods that contribute to the V-4’s low engine weight. Also important is the use of magnesium (only 64 percent of the density of aluminum) for nonstructural case and cam covers plus the deep oil sump and forward fairing mount/air intake.
This is what the Ducati Superbike has become: a vehicle engineered for production (the “affordable exotic”) yet incorporating the latest insights from Motogp, with style we expect from Italy’s historic role as the crossroads of design. Motorcycle evolution never ceases, so there can be no ultimate. This new V-4 shows Ducati is determined to lead the advance.
TOP LEFT: The intakes stack up to where the fuel tank would be, making the engine look tall. It’s actually 1.1 inches shorter top to bottom than the 1299 engine, and 1.5 inches shorter front to back.
ABOVE: The tail of the bike is light, in more ways than one—the rear subframe weighs 4.2 pounds. OPPOSITE: The engine is 1.7 inches wider than a 1299, but the V-4 keeps the waspy Panigale shape.
OPPOSITE: When asked which part of the Panigale V-4 he would hang in his house, the V-4’s designer, Julien Clement, said: “The second panel of the fairing, the internal one. I really like this concept.”
The front subframe cradling the headlight and mirrors is magnesium and weighs 1.5 pounds—every little bit helps.