2005 Benelli TNT
TNT: Trinitrotoluene (TNT) is an explosive chemical and a part of many explosive mixtures, such as when mixed with ammonium nitrate to form amatol. It is prepared by the nitration of toluene (C6H5CH3), it has a chemical formula of C6H2(NO2)3CH3.
This is the definition of Trinitrotoluene, better known in its abbreviated form as TNT: a powerful but stable explosive that is insensitive to friction and jarring and needs a detonator to set it off.
Benelli admitted at the time it presented the new TNT - Naked/Cafe Racer that it aimed to combine the dynamic qualities of the Tornado 900 Tre supersports bike and the new three-cylinder 1130 cc engine developed by the firm. The result was to be the most explosive and powerful bike, but also the most enjoyable and exciting on the market.
But the bike also had to be a logical continuation of the Tornado range. It had to retain the latter's unique character and style, an unmistakable Benelli trade-mark. The TNT's first dynamic tests allow us to say right now that we have certainly achieved this.
OBJECTIVES OF THE TNT
Here's what Andrea Merloni, president of Benelli, has to say about the TNT project:
"We wanted a bike with a comfortable riding position, with body slightly forward, slightly raised footrests to allow angling on corners, wide handlebars for complete control and effective but softened suspensions to guarantee comfort under any circumstances and to gradually tap the enormous torque available with a twist of the throttle. Basically, we wanted to put together all of the exhilarating feelings that only true Naked/Streetfighter bikes can offer".
. and about the engine;
"The natural heir to the '70s Café Racer, designed to burn up the road between traffic lights rather than travel long distances or cruise at high speeds, our Naked bike needed an engine that had lots of torque even at low speeds and was very flexible.
That's what we were aiming for when we started developing the new engine.
By increasing the stroke of our sports engine, we were looking for good torque at low speeds but we also increased the power. Today we can safely say that we have created our first "Long Stroke" sports engine.
Definition of the Benelli TNT project
Four basic characteristics were identified at the moment of project definition.
1. Appeal and exclusivity of design to heighten owner pride.
2. Torque: the best in its category at low RPM to ensure superb out-of-the-bend performance and smooth handling on easier roads.
3. Making the TNT agile, to exploit the engine and the chassis's superb potential on mixed-road routes and under any circumstances.
4. Excellent high speed stability for good motorcycle control on the motorway, allowing maintenance of high average speeds, albeit at the expense of aerodynamic comfort.
The Tre "LONG STROKE" 1130 cc
"We wanted the engine to have real character, an unmistakable growl, good torque even at low RPM for lightning-fast acceleration, in short, an engine that would give a docile, controlled response with gentle twists of the accelerator and explosive performance when turned sharply to full throttle".
"Although one of the priorities when developing the engine was to guarantee plenty of torque at low speeds, we had to face the fact that power was essential too".
With over 80% of the components developed from scratch compared with the 900 TRE "Sport", the Tornado engine, the TRE "Long Stoke" is much more than a simple evolution. It is a brand new engine category. The new 3-cylinder, in-line, 4-stroke, DOHC (double overhead camshaft), 12-valve liquid-cooled engine has been designed to offer the same intense exhilaration as the Tornado's 3-cylinder 900 cc.
The TNT's new "Long Stroke" engine has pushed back the boundaries for the entire Naked category. It is designed to offer better performance, high top power and torque, maintaining a fast response. Moreover, it has been developed with an eye to environmental protection, since even without a catalytic converter, it is Euro 2-compliant.
Further development of the TRE "Long Stroke" 1130 cc engine
To differentiate the "Long Stroke" engine from the "Sports" engine in terms of performance (additional torque at low RPM, reduced max. RPM) and maintain power levels, the following points have been modified:
Increased cylinder capacity
Shape of the combustion chamber, making it perfectly hemispherical and Euro 2-compliant even without a catalytic converter
Intake valve camshaft
The increased cylinder capacity compared with the 900 TRE "Sport" was achieved by extending the "Long Stoke" engine piston stroke with a modification to the crankshaft, whilst the cylinder bore remains unchanged. The longer stroke combined with the raised intake valve camshaft increase engine torque and make power delivery particularly smooth at low RPM.
Lengthening of the air intake duct and primary exhausts has helped lower max. RPM, providing low-RPM torque and power levels.
The perfectly hemispherical combustion chamber improves combustion efficiency and makes the motorcycles Euro 2-compliant even without any need for a catalytic converter.
The new "dovetail" structure brings the angle to 0°, improving neutral selection at standstill and giving a smoother passage to first gear.
The clutch has been altered to adapt it to the higher torque produced by the engine. A lathed disc has been added and spring load reduced to lower the lever pressure.
Electronic fuel injection system
Important innovative progress has been made on the electronic injection system. A new control unit, specially designed for 3-cylinder engines, provides greatly improved injection - ignition mapping with close-knit control break points.
To ensure high efficiency throughout the new engine's entire power range, the electronic injection system has no less than eight sensors checking the status of the various systems, i.e.:
Identification of the cylinder which is at the combustion phase
Identification of the number of revolutions
Intake air temperature
Cooling water temperature
Position of the valves
Position of the throttle
Data from these eight sensors is processed by a microcomputer, then re-transmitted to the electronic injection control system, which adjusts the flow of fuel injected into each cylinder via throttle valves 53 mm in diameter.
A solenoid valve, controlled as a function of the throttle angle and RPM, adjusts filter box air intake and exhaust gas flow at the end of the primary exhaust pipes in order to provide improved engine torque at intermediate RPM and to improve the high-RPM sound of the engine, making it unique.
An important innovation, the only of its kind in the world, has been implemented in the 2005 year
version: the possibility of modifying motor functions by simply pressing a lighted button on the dash support. The engine control unit can be switched between free power and controlled power for better control of the motorcycle in poor traction conditions with a decrease in fuel consumption of 10-20% depending on driving style and on the road. The free power configuration makes it possible to fully enjoy the torque features and motor power, while the controlled power configuration makes it possible to enjoy using the bike in the city in torque and on asphalt with poor traction without stress.
New cylinders and pistons
The new sleeveless cylinders are coated with a Nikasil anti-friction treatment.
The longer piston stroke required a lengthened lower cylinder section to provide total control of the piston and consequently reduce wear.
More uniform temperatures are achieved thanks to increased water flow around the various ducts and joints.
Higher-level crankshaft performance is optimised by newly developed pistons, forged with a low skirt and low friction coefficient.
To reduce oil consumption and improve the seal, the piston profile has been revised. A lower skirt makes the piston lighter and a more rounded profile improves guidance.
The lowered pistons, reduced RPM and extended stroke means that shorter, lighter rods can be used. As a result, crankshaft balance has also been revised.
The countershaft, which compensates for the alternating forces, has been redesigned to take the new masses in reciprocating motion into account.
Timing is of the DOHC type with 4 valves per cylinder, arranged with a very tight angle between the valve axes, operated directly by the bucket tappets for high efficiency at all speeds.
Improved torque at low RPM and reduced maximum RPM were obtained thanks to a cam with lower lift and a shorter timing chart. This gives smoother power output at low RPM especially during city rides.
Many significant innovative changes have been made to the transmission to provide smoother, more immediate gear selection.
Oil flow rate to the primary shaft grooves has been increased and a new, more rigid clutch (without slipper system) has been adopted.
New cooling systems
Water radiator cooling system
The need for a seat height reduced to just 780 mm meant that the radiator had to be repositioned. On the Tornado it was under the seat.
On the TNT they are at the sides of the engine head for even weight distribution and good cooling performance.
Two intakes carry fresh air to the water-filled radiators even at low speeds and two high-efficiency fans help cool the water in the radiators during low speed city rides.
Oil cooling system
Cooling efficiency is also guaranteed by the light forward-facing aluminium oil radiator which dissipates engine heat via the oil flowing through it.
An appropriately regulated distributor ensures that the correct quantity of cooling fluid is fed through the oil radiator circuit.
The exhaust system consists of primary stainless steel manifolds (diameter 42 mm) interconnected by a compensator which improves engine efficiency at intermediate engine speeds of 4000 - 5500 RPM.
The three-in-one converges into a 60 mm pipe. Exhaust pipe flow-through is regulated by a butterfly valve controlled by a solenoid valve which is, in turn, governed by the injection controller as a function of accelerator throttle angle and engine RPM, to improve and smooth engine performance between 1500 and 4500 RPM.
From here the system connects to the under-seat elliptical silencer. Extremely light, its interior consists of two compensation chambers designed to give the TNT a unique, unmistakable sound.
Two solutions are used to prevent the transmission of heat to the seat;
The entire exhaust system is separated from the seat by a plastic buffer resistant to high temperatures.
The silencer has an inner insulating core which reduces under-seat heat transmission.
SUMMARY OF ENGINE TECHNICAL SPECIFICATIONS
80% of engine components are newly designed!
New in-line 3-cylinder 4-stroke liquid-cooled 1131 cc engine
DOHC 4-valve head with lateral timing chain
Electronic injection with 53 mm throttle bodies
7.5 litre filter box with electronically controlled regulator and dynamic air intake
Cylinders with Nikasil anti-friction treatment
Forged pistons with low skirt
Crankshaft and countershaft balancing
Newly designed gear selection
Increased primary shaft lubrication for smoother gear changes
New intake camshaft
New exhaust system with electronic regulator valve, consisting of a 53 mm diameter butterfly valve positioned downstream of the 3-in-1.
New hemispherical combustion chamber which makes the motorcycle compliant with Euro-2 antipollution standards without the need to add a catalytic converter
Exhaust mufflers with 2-chamber interiors and an aluminium shell
Cooling system having 2 lateral radiators with dynamic air intake and twin cooling fans
Oil cooling system with a large forward-facing radiator
137 HP / 101 kW at 9250 RPM
12 KgM (118 Nm) at 6500 RPM
TNT project objectives
"We aimed to give a sensation of stability and easy handling. The starting point for development of the motorcycle was mixed-road performance. We've worked hard on getting the set-up just right, especially weight distribution and suspension settings. We were also intent on achieving good ride comfort, but without compromising when it came to medium-speed mixed-road rides. Use of 50 mm forks has made the bike precise and safe going into a bend at medium speeds".
The frame is derived from the tried and tested Tornado 900 Tre. Four years of experience on race circuits all over the world is clearly reflected in the TNT's frame, essentially identical to the one on the Tornado.
Handling characteristics have been altered, with easier, more intuitive handling thanks to set-up changes at both front and rear.
In particular, the front end has been raised 15 mm and the rear end lowered 15 mm to give:
a steering angle of 25.5° and weight distribution of 52% at the front and 48% at the rear.
A tough 50 mm fork makes the front end solid and precise, whilst the rear end has the world's only light Ergal-bodied shock absorber, which ensures constant high level performance and a safe ride whatever the road conditions.
The entire frame was designed using CAD (Computer Aided Design) systems before approval.
The lightweight swingarm is a tough, tubular alloy trellis frame made by welding together precision-cast steel elements. The alloy tubes are hand-welded. It is a natural extension of the chassis structure and gives outstanding torsional and bending rigidity.
Another innovation is the sub-frame which hides the exhaust muffler, made of die-case aluminium just 2.5 mm thick.
For user-friendly maintenance, the rear wheel cam allows for easy chain tension adjustment.
Like the Tornado, the TNT also has a state-of-the-art Brembo braking system.
Front brakes TNT
Callipers with 4 pistons (diameter 34-32 mm) and twin brake discs (diameter 320 mm)
15 mm pump with incorporated tank
4-position adjustable lever
Metal-braided hoses with an internal Teflon lining
Front brakes TNT Sport
twin radial 4-piston caliper
15 mm pump with incorporated tank
4-position adjustable lever
Metal-braided hoses with an internal Teflon lining
Rear brakes TNT and TNT Sport
Calliper with twin pistons (diameter 34 mm)
New pump attached to the frame by a special support and connected with a metal-braided hose with an internal Teflon lining.
The Marzocchi "upside down" fork diameter 50 mm on the TNT Sport is also adjustable in compression and extension with spring pre-load.
The exclusively designed 5-spoke alloy wheels clearly place the Benelli TNT in the same family as the Tornado.
These wheels are light and have excellent rigidity, giving fast, precise into-the-bend handling and good stress absorption.
They mount high-grip tyres, front 120/70 ZR 17 and rear 190/50 ZR 17.
The handlebars are made of variable cross-section extruded Ergal tubes.
The TNT is bristling with components which illustrate the care that has gone its the construction: fork bottoms, handlebar support, rider and passenger footrest supports, footrests and rear brake calliper support.
The instrument panel is directly derived from that of the Tornado, the only difference being the graphic design adapted to the TNT.
The panel includes a temperature readout, fuel indicator, injection system diagnostics light, routine maintenance schedule indicator and lap time chronometer.
The electrical system can be fitted with a sophisticated "immobiliser" type anti-theft system, connected to the electronic injection system via the ECU (electronic control unit).
SUMMARY OF FRAME TECHNICAL SPECIFICATIONS
High-strength tubular trellis frame combined with cast aluminium parts connected with adhesive and fixing screws
50 mm fork stanchions and swingarm length 565 mm
Fork angle 24.5º
Wheelbase of 1410 mm
Rear shock absorber with Ergal 55 body, set up to optimise ride comfort
Die-cast aluminium subframe and rear part
Chain adjuster cam
5-spoke alloy wheels
Variable-section extruded Ergal handlebars
Footrests in forged aluminium with rubber trim
Twin front brake discs, diameter 320 mm
Front brake calliper with twin pistons, diameter 30:34
Rear brake disc, diameter 240 mm
Rear brake calliper with twin pistons, diameter 32 mm
Seat height 780 mm
"A naked must be, first and foremost, low-slung, narrow and forward-leaning. This being the case, the first thing that had to be done was to shift the radiators to the front of the motorcycle. However, this did not necessarily mean that the design would be of the classic naked variety. My personal viewpoint was that it should be more like a streetfighter, a type of motorcycle much loved by the British and Italians".
"In my opinion, a streetfighter should highlight the contrast between the sizeable, almost heavy front section and the tapered rear; placing the radiators alongside the fuel tank and angling them to create a forward-facing "V" provides a perfect response to the technical and styling needs of the TNT. Similarly, the single-silencer under-seat exhaust accentuates the tapering effect towards the rear of the TNT".
"It was important that both front and rear views should project the image of an aggressive, unique vehicle and I think the unique design of the two light clusters helps us achieve that very well".
"The light clusters consist of six front lights with a low, long, aerodynamically corrected profile to help reduce pressure on the rider and two rear elements, each consisting of nine LEDs, separated by the exhaust silencer".
Design and Technical Features
"A simple design with few painted parts, but plenty of personality".
All mechanical parts were designed to maximise "DESIGN & FUNCTION"
This is shown by the rear part and the thin high pressure cast aluminium seat guard, as well as the part supporting the lights and front instruments.
The fuel tank has a capacity of 17 litres and allows for comfortable leg positioning. Two removable lateral covers allow easy bike customisation without having to disassemble the fuel tank.
The truly exclusive front headlight is a triumph of design and efficiency. Not only does it make the bike unique and unmistakable from the front, but with its 6 bulbs actively contributes to active and passive rider safety.
Six 55 W bulbs are used in the dipped headlights, whilst two 15 W bulbs provide the position lighting.
Exclusive Design and Safety objectives are achieved, but at a price.
To balance the feisty-looking front lights, the rear lights consist of 2 independent elements, positioned at the sides of the exhaust for improved safety.
This original layout is a distinguishing feature of the Benelli TNT rear section.
Colours available from April;
Anti-theft system and alarm with "immobiliser"
Open muffler silencer
Raised top fairing
Fuel tank pannier
Fork extension/compression adjuster kit
Rear shock pre-load adjuster kit
Ergal 55 z=39.40 gear
Engine - 4 stroke, 3 cylinders in line, tilted forwards 15°, fitted with anti-vibration countershaft
Bore x stroke - 88 x 62 mm
Engine Displacement - 1130 cc
Compression ratio - 11,5:1
Cooling system - liquid, with lateral double radiator, served by two electrofans
Oil cooling system - with radiator
Distribution - chain driven double head cam shaft with 4 valves per cylinder
Lubrication - wet sump
Max power/rpm - 101 kW at 9250 rpm
Max torque/rpm - 117 Nm at 6750 rpm
Carburation - electronic injection with 1 injector per cylinder
Ignition - single coil inductive discharge electronic ignition
Clutch - wet clutch
Gearbox - 6-speed extractable
Transmission - straight toothed primary gear, chain driven secondary
Frame - mixed solution. Front: ASD steel tube trellis, fastened with screws to boxed rear section, aluminium alloy castings
Subframe: aluminium die-case
Suspension - front: Marzocchi 50 mm diameter "upside down" fork, rear: ASD steel tube trellis swingarm with Extreme Technology single shock absorber with adjustable extension and spring pre-load
Wheels in gravity moulded aluminium alloy, front 3.5", rear 6.00"
Tyres - Tubeless, radial; Front 120/70 x 17" - 120/65 x 17"; Rear 190/50 x 17" - 200/50 x 17" - 180/55 x 17"
Brakes - Brembo; Front: twin floating disk, 320 mm diameter, with 4 piston caliper; rear: single disk, 240 mm diameter, with twin piston caliper
Dimensions - wheelbase 1419 mm, seat height - 780 mm
Dry weight - 199 kg