Romano Albesiano Piaggio Group Director of Motorcycle Engineering
GOAL: To build the fastest bike on the track Brief : to create the missing link between the track and the road . Limitations : None! Focal points for development Starting from a blank sheet of paper meant being able to explore every possible solution in terms of engine and chassis technology, remaining faithful to Aprilia's commitment to the pursuit of total performance built on experience gained on the race track and, in this case in particular, drawing from the victorious heritage of the RSV
Mass integration and balancing
Performance profiles tailored specifically for results on the track
65° V4: The starting point The first task: defining the best possible solution together with the chassis and suspension engineers and the race division Defining the heart of the bike Defining the engine: the most delicate decision in the project, which would determine every aspect of the bike. The goals were established for weight, dimensions and, most crucially of all, how the engine was to be integrated into the frame architecture (in terms of centres of gravity and polar moments of inertia) V2 Momenti polari di inerzia V4
65° V4: The starting point The engine had to: 1. Remain faithful to Aprilia's commitment to setting new benchmarks for handling, stability and speed The result of painstaking studies conducted together with the vehicle engineers to define optimum solutions for centre of gravity and moments of inertia and to determine the ideal locations for the engine and other components 2. Ensuring class beating performance in terms of power output and power delivery Identifying the character to give the engine, to allow the rider to make full use of the potential of the engine itself and the vehicle, offering a levels of performance never experienced before off the racetrack. Initial proposal for engine layout Initial proposal for engine layout
65° V4: The starting point State-of-the-art virtual systems were used to simulate laps on a circuit with a variety of in-line and V configuration 2, 3 and 4 cylinder engine layouts, to identify the respective advantages and disadvantages of each engine and their effectiveness in terms of global performance. Models were then built with dimensions, centres of gravity, polar moment of inertia locations, engine characteristics and all other parameters necessary to assess the behaviour of the vehicle.
The engineers opted for a 65° V4 engine layout, the core around which every other aspect of the bike took shape 65° V4: The starting point - The engine sits perfectly in the frame, optimising mass distribution and significantly improving dynamic balance The perfect engineering solution to achieve a chassis architecture that allows the engine to express its full potential In light of these significant advantages, the higher development and manufacturing costs were deemed worthwhile - Less vibration that an in-line 4 Why a 65° V4? - Narrower than any other 4 cylinder layout
Claudio Lombardi RSV4 Engine project manager Luigi Dall’Igna Engineering Director for the Aprilia Racing Division
65° V4 - Engine architecture The angle of the V has been opened up relative to the old twin cylinder unit to 65°, to optimise the intake ducts and maximise the fluid dynamic efficiency of the engine. The angle of the V was also determined by the chassis architecture: once the overall dimensions were calculated, the maximum swing arm length was defined. A 65° V offers ample scope for further development, allowing bigger bores that would be impracticable for space reasons in an in-line engine V= SUPREME COMPACTNESS V4: 225 mm L4: 400 mm 65°
65° V4 - Engine architecture Minimised external dimensions and balancer countershaft to attenuate vibration . The result is an engine that vibrates less than an in-line 4. “ Reed valves ”, installed for the first time ever near the exhaust ducts , to allow air into the exhaust gas and enable combustion of harmful HC and CO emissions. - Non-structural components in magnesium alloy - Aluminium monobloc crankcase To keep the weight of the engine down, the following solutions were used :
65° V4 – Cylinder Head & Camshafts The gear pair at the centre of the cylinder bank transmits drive to the exhaust camshaft. This innovative solution reduces the external dimensions of the cylinder head on the exhaust side. Timing system with lateral chain and central gears to minimise head size in the area underneath the frame spars. Together with the 65° V layout, this has made it possible to achieve overall dimensions comparable to a twin cylinder unit of equal capacity. The lateral timing chain drives the intake camshaft only, resulting in a compact layout while ensuring the high timing precision necessary and chain durability.
65° V4 - Performance The fluid dynamic efficiency of the engine has been optimised by fine tuning the shape and size of the intake and exhaust ducts with mono and three dimensional modelling software used by the Racing Division. Every single component has been rationalised , resulting in a maximum power of 180 bhp and 115 Nm of torque. This, together with the adoption of 32 mm intake valves in titanium , has made higher engine speeds possible
Monodimensional simulation software allowed the engineers to evaluate a number of different configurations for the exhaust system to strike an acceptable compromise between performance, emissions reduction and noise.
The improvements in mechanical efficiency (reduced friction losses) have been made possible by:
Minimising the amount of oil used for lubrication and for feeding the crankshaft and connecting rod bearings
Motorsports-derived crankshaft oil gallery design for
minimising oil pressure.
- Minimised weight for all rotating and reciprocating components
- Reduced power losses due to internal pumping effects into the engine
65° V4 - Performance
Two injectors per cylinder : one located down stream of the throttle valve for excellent responsiveness at lower engine speeds, due to its vicinity to the intake valve and another in the airbox , which starts to work at higher loads and engine speeds , for more effective fuel atomisation and vaporisation and increased power output. A butterfly valve in the exhaust controlled by the engine control unit enables the use of a lower back pressure silencer while complying with noise emissions legislation. Aprilia's racing experience was put to use to define a particularly caompact combustion chamber with sufficiently large squish values to enable the use of very high compression ratios 65° V4 - Performance
65° V4 - Race prototype solutions The cassette gearbox is a solution used in race prototypes to allow rapid gear ratio replacement and shorten gearbox maintenance times. The desire to create a race-ready V4 superbike led Aprilia to adopt uniquely advanced solutions . The technological excellence of the V4 engine is complemented by electronically controlled variable length intake ducts. At low revs and loads, the long duct favours torque and smooth power delivery . When the rider requests maximum performance, the upper section of the intake duct rises and separates from the lower part: the duct is therefore shortened and optimised for maximum power delivery . The multiplate wet clutch features a mechanical slipper clutch system for maximum engine braking torque control and motorcycle stability under hard braking for greater precision in setting the bike up for corners and maintaining trajectories.
65° V4 - Electronic engine and vehicle management
Triple engine mapping selectable by the rider from the handlebar, to change the power delivery mode of the engine and the character of the bike on the fly.
TRACK : no compromise on the circuit. Unleashes the full 180 bhp of fury at the slightest twist of the grip. Recommended for expert riders in ideal grip conditions
SPORT : for first timers on the track, for limited grip conditions or for pure fun on the road. Smooth power delivery. Torque limited in the first 3 gears for greater bike control. For an exciting but less challenging ride
ROAD : for enjoyable ride: power limited to approximately 140 bhp in all gears. Greater rideability in all conditions.
FULL RIDE BY WIRE Full Ride by Wire : no direct connection between the throttle grip and the throttle valves, which are controlled by a dedicated latest generation dual processor Marelli control unit which manages the torque produced by the engine by controlling air, fuel and ignition. Each cylinder bank has its own dedicated servo motor which exclusively operates the respective two throttle bodies only for independent management of the two cylinder banks and of the quantity of fuel injected into each pair of cylinders. While this solution has been tried and tested by Aprilia, it has never been applied before on such a powerful production engine, thus opening up practically infinite possibilities for power delivery control .
RSV4 RbW system Hi Speed CAN line MAP 1 Sens A/B V Supply 7sm ECU MAP 2 Sens 3/4 DC Motor 2 V Supply RbW2 Intake ducts Sens 1/2 DC Motor 1 V Supply Sens C/D Sens Air cut V Supply DC Motor Valve Exhaust Demand Instrument panel RbW1
Romano Albesiano Piaggio Group Director of Motorcycle Engineering Luigi Dall’Igna Engineering Director for the Aprilia Racing Division
Chassis architecture: The perfect balance Years of world class racing and victories are encapsulated in a racing chassis developed by the Aprilia research and development division in close collaboration with the racing division, with construction solutions and a degree of adjustability that only racing prototypes can boast. RSV4 FACTORY embodies the essence of its race sibling, setting the benchmark for compactness and agility in its class. Centralising the masses perfectly was a fundamental prerequisite in the definition of the chassis and the layout of the bike's components . Everything was built around the engine to bring the centre of gravity of the engine itself as close as possible to the centre of gravity of the vehicle. The result: unparalleled handling, stability and speed through the curves . As in MotoGP prototypes, the tank is located so that the majority of the fuel sits under the saddle, optimising bike balance and cancelling out handling differences between full and empty tank conditions. The weight distribution is on a par with that of a genuine race machine, for a bike that is perfectly balanced and easily tailored to suit the preferences of each individual rider
Chassis: explored solutions Prima ipotesi layout Prima ipotesi layout Ipotesi Telaio componibile
Chassis architecture: Frame The unique construction technology allows both the frame and the swing arm to proudly flaunt the naturally gleaming colour of aluminium , meaning that the bike even looks like a race prototype. Cast and pressed aluminium elements are welded together to create a frame that beats even the benchmark twin cylinder RSV 1000 in terms of stiffness. Torsional and flexional rigidity have been optimised for perfect feeling and control and to allow the rider to handle Superbike levels of power with confidence. Made from aluminium using unique construction technology, the frame of the RSV4 Factory weighs just 10.1 Kg - a lightness only matched by racing bike frames. Comparative frame rigidity V4 - V2 With engine Weight (Kg) +4 % Torsional rigidity (Kgm/deg) +39 % Yaw rigidity (Kg/mm) -16 % Longit. flexional rigidity +16 %
To exploit the full potential of the chassis and allow the bike to be tailored to the style and preferences of the rider or the characteristics of the track, the RSV4 FACTORY offers practically infinite scope for adjustment Introducing capabilities never seen before on a production bike. RSV4 FACTORY is a true track-ready bike.
Lightness The forged aluminium wheels, featuring an all-new design, contribute to a further weight reduction of approximately 1 Kg compared with the twin cylinder RSV 1000 Factory, for improved agility through the curves. Together with the new brake disc, they contribute to minimising unsprung mass and rotational inertia, improving responsiveness and precision in setting the bike up for curves . Advanced modelling systems have been used to optimise chassis element cross sections and thicknesses . The swing arm weighs just 5.1 Kg , for improved shock absorber function and allowing the rider to read the road surface more precisely . Comparative swing arm rigidity V4 - V2 Weight (Kg) +12 % Torsional rig. (Kgm/deg) +23 % Yaw rig. (Kg/mm) +64 %
Millimetre-precise adjustability The new upside down Öhlins Racing front fork has 43 mm stanchions and a titanium nitride coating . Wheel travel is 120 mm. The fork features micrometrically adjustable hydraulic compression and rebound damping and spring preload . The progressive rear suspension includes a new Öhlins Racing piggy back design shock absorber with adjustable spring preload, compression travel and length. This allows adjustment to the height of the rear end to tailor the setup to different riding styles and circuits. Wheel travel is 130 mm. Adjustable Öhlins Racing steering damper for impeccable high speed stability and millimetre precision in setting the bike up for curves.
Awesome stopping power Radial monobloc Brembo callipers: powerful, modulable and fade resistant The 320 mm dual floating discs were developed specifically for this bike . A low profile steel rotor and asymmetric cross-drilling offer improved modulability while lightening the front wheel by approximately 500 g . The floating retainer is fastened to the flange with 6 pins only in order to minimise inertia and weight . A radial brake pump is used to improve precision and lever feel. The Brembo “Serie Oro” rear braking system features a new 220 mm stainless steel disc and a two piston calliper. A racing pump is used with a lightweight reservoir.
Miguel Galluzzi Director of the Piaggio Group Style Centre
Just a few, simple and bold styling elements emphasising the unique engineering qualities of the chassis and engine and merging them as aesthetic features in their own right. Extreme compactness : smaller, narrower and sleeker than any bike of this class has ever been. An almost obsessive research of perfect ergonomics , a trademark of all Aprilia motorcycles. Extensive aerodynamic studies to minimize surfaces without compromising aerodynamic efficiency. Performance becomes design No concession to purely aesthetic choices: the design and engineering of each component fuse in an unparalleled symphony of function for the track. Performance becomes design: every detail is conceived for functionality and performance. Nothing has been added for the sake of beauty alone, with each aspect giving shape to the technology within. Brief: Style serving technology
Unique personality The tapering lines of the ultra-compact tail fairing seems to melt away into space , while the LED taillight, embedded under the tail, offers outstanding lighting power. The needs to optimise dynamic intake system feeding the V4 dictated the extra-large air intakes, which not only develop considerable overpressure in the airbox (approx. 35 mb at 280 km/h), but also completely separate the headlamps from the bottom of the top fairing. The result is a look that is unique , technological and unquestionably aggressive . The triple headlamp design is inspired by the original Aprilia maxi-sportsbike, the 1998 RSV . The parabolic headlight mirror was developed using state of the art calculation systems to ensure maximum light efficiency at night-time conditions together with minimised weight and dimensions .