2005 S2000 : Overview

INTRODUCTION The Honda S2000 is a high-performance, 2-seat, open-topped based on the SSM concept car first shown at the 1995 . Designed to be fun to drive, the S2000 uses an advanced front-engine, rear-wheel-drive sports-car configuration, and also incorporates world-class safety features.

Many of the lessons learned in four decades of building racing cars and motorcycles are incorporated into the S2000's design. The S2000 is produced at Honda's Takanezawa plant in Tochigi, Japan, where such cars as the NSX and the are built.

What's New For 2005 o New colour - Silverstone metallic with 2-tone red and black leather interior

Colour and Trim Exterior Interior (Leather) Berlina Black Black or Black/Red Sebring Silver Metallic Black or Black/Red Solar Yellow Pearl Black Grand Prix White Black/Red Silverstone Metallic Black or Black/Red

MARKETING POSITION We all know that sports cars have enjoyed a resurgence of popularity recently, as vehicles like the BMW Z3, Porsche Boxster and Mercedes-Benz SLK have ignited the market. We see continued excitement in this market segment, with the addition of the Audi TT Coupe and Roadster, and the rebirth of the Nissan 350 Z.

Top Competitive Models Primary BMW Z4 Porsche Boxster Mercedes-Benz SLK Audi TT Nissan 350Z

KEY DEMOGRAPHICS We see this in our key competitors' demographics in this segment: mainly men, in their mid- forties to early fifties, married, with household incomes above $100,000. The number one reason these buyers cite for their purchase decision is that they want a vehicle that's 'fun to drive'.

The target demographics are 70 percent male, 60 percent married, median age of 40-plus, and median household income above $100,000.

To these buyers, Honda's brand image, its racing heritage, and its tradition of technological innovation will be the primary purchase motivation.

And while we don't expect the majority of our buyers to look at the competition, we know you will and we're not afraid to compete head-to-head.

2005 Honda S2000 1 The S2000 is more technically advanced and provides a more thrilling driving experience than its competitors.

Many of these buyers are coming out of other sporty-type cars, or other vehicles within the same brand family.

These buyers know what they want. The majority are not cross-shopping other vehicles at all, even within this category. Brand image is all-important to these buyers. Demographics are one of the factors driving this resurgence.

Baby Boomers, reaching their peak earning years, are looking to recapture their youth - a time when they might have been driving MGs or Triumphs.

S2000 Gender 70% Male Status 60% Married Median Age 40+ Household Income $100K+ University & Education 70%+

Z3 L4 Z3 L6 SLK Boxster* Male 71% 73% 66% 81% Married 57% 55% 46% 72% Median Age 46 45 43 48 Median Income 157K 223K 175K 166K College + 71% 62% 61% 85% *(US Data)

2005 Honda S2000 : Body

BODY - OVERVIEW The S2000 is the production version of the stylish SSM concept car that Honda first showed at the 1995 Tokyo Motor Show. Like the SSM, the S2000 is an open-topped, two-seat roadster, designed for enthusiast drivers. The S2000 body and interior also incorporate class-leading safety, quality and comfort features.

HONDA S2000 BODY FEATURES o Electrically powered soft top o Integrated roll bars o High-intensity discharge (HID), projector-type headlights o 17-inch alloy wheels o Body-coloured dual power mirrors o Dual exhaust o Impact-absorbing, 8-km/h, body-coloured bumpers o Wind deflector

HONDA S2000 EXTERIOR DIMENSIONS

Millimeters Length: 4,118

2005 Honda S2000 2 Width: 1,750 Height: 1,285 : 2,400 Track, Front: 1,470 Track, Rear: 1,510 Kilograms Curb Weight: 1,290 Weight Distribution (%, Front/Rear) 49/51

EXTERIOR STYLING AND DESIGN The S2000’s styling is distinctive and presents a modern, dynamic look. Its long hood and wide front end create a visual impression of lowness and mass. The hoodline drops away to a low, strong nose shaped for minimal aerodynamic drag and good forward visibility.

The S2000’s clear-lens, multi-reflector headlights and exterior line sweep back from the leading edge of the fenders. The lamps are a high-intensity discharge (HID) projector type that throw a powerful, broad beam. Side reflectors, parking and directional lights are combined in the same units.

The outside mirrors and door handles are body-coloured. The S2000 badge on the front fender and Honda badges on the hood and trunk are the only identifying marks on the car.

In profile, the S2000 looks taut and aggressive. Its broad sides visually convey strength and mass. The gap between the outer sidewalls and the outer edges of the fenderwells has been minimized, giving the car a wide and stable look.

The main character line of the car rises from the headlights, along the top of the fender and the top of the door, to the high rear deck, for an aggressive, raked look. Sculpted lower side sills further enhance the car’s angular appearance, and serve to draw the eye to the S2000’s large, flared wheelwells and high-performance wheels and tires.

The 17-inch aluminum-alloy wheels are an open, 5-spoke pattern that calls attention to the S2000’s large brake discs and calipers.

A small with an LED stoplight is integrated into the trailing edge of the trunk lid. Large, round taillights set in clear-lens housings and dual, chromed exhaust tips visually dominate the rear view of the car.

The S2000’s trunk volume is 152 litres. A space-saver spare tire is stored on a shelf, separated from the rest of the trunk by the carpeted trunk liner.

Fuel-tank capacity is 50 litres.

CONVERTIBLE TOP The S2000 features a power-operated rear glass, soft convertible top. Pushing the switch on the centre console opens or closes the top in about six seconds, and latches at the top of the windshield hold it securely. When folded, the top stows compactly behind the cockpit. A soft boot cover snaps in place to protect the top.

ROLL BARS AND AIR DEFLECTOR The S2000’s roll bars combine with the car’s reinforced windshield frame to help form a protective area for the driver’s and passenger’s heads in the event of a rollover. A clear acrylic panel acts as a wind deflector to help reduce cockpit turbulence.

NVH COUNTERMEASURES Measures employed on the S2000 to minimize and control NVH (noise, vibration and harshness) include vibration-absorbing engine mounts and suspension bushings, resonance-

2005 Honda S2000 3 damping chambers in the intake and exhaust systems and soundproof materials applied to the floor, floor tunnel and trunk.

REMOVEABLE HARD TOP The S2000 is also available with a handsome removable hard top. Easy installed or removed by two people, the hard top adds a luxurious look to this true . A storage stand and protective cover are also available for the storage of your hard top when not in use.

2005 Honda S2000 : Chassis

CHASSIS - OVERVIEW A front-engine/rear-wheel-drive configuration was chosen for the S2000. This "classic" layout is widely regarded for its excellent handling characteristics and direct, linear response to control inputs from steering, brakes and throttle–especially when approaching the chassis and tires’ adhesion limit.

Since optimum weight distribution and balance are such important factors in achieving excellent handling characteristics, Honda engineers set the S2000’s engine and drivetrain as low and close to the centre of the chassis as possible. Suspension geometry–, caster, camber, roll centres, etc.–also have a tremendous effect on handling and response, so Honda engineers designed an all-new double wish-bone suspension for the S2000 with optimum geometry.

Steering is by an electrically assisted, power rack-and-pinion system, similar to the system used on the NSX. The braking system uses 4-wheel discs and ABS. The system has been specially engineered for optimum efficiency, feedback and control.

The following Honda-designed chassis features contribute to the S2000’s exceptional handling and response: o 49/51 (front/rear) weight distribution o Entire drivetrain located behind the centreline of the front axle (front mid-engine layout). This helps lower the vehicle’s centre of gravity and helps to centralize vehicle mass, resulting in a low yaw moment and more responsive vehicle behavior o Wide track (1470 mm front/1510 mm rear) contributes to vehicle stability and chassis rigidity o Highly rigid "high X-bone frame" o Compact, highly rigid 4-wheel "in-wheel" double wishbone suspension allows for low hoodline o Mono-tube shock absorbers o Electric system o Four-wheel disc brakes (300 mm vented front/282 mm. solid rear), with Honda- designed 3-channel ABS o Limited-slip differential

49/51 WEIGHT DISTRIBUTION Honda engineers wanted the S2000 to have a balanced 49/51 (front-to-rear) weight distribution, considered ideal for a front-engine rear-wheel-drive roadster. To accomplish this, and also lower the centre of gravity, Honda engineers placed the engine and transmission low in the chassis and behind the front suspension.

CENTRALIZED MASS, LOW YAW MOMENT Five decades of designing and building racing cars and motorcycles has taught Honda engineers the value of centralizing a vehicle’s mass–placing as much weight as possible close to the centre of the vehicle. The result is what engineers call a "low polar moment of inertia," which gives the vehicle a lower yaw moment–or less steering delay–which translates into quicker, more linear steering response.

2005 Honda S2000 4 Since light weight is a performance asset, Honda engineers also took great pains to design the S2000’s various chassis components to be as light and as compact as possible.

HIGHLY RIGID BODY AND FRAME The S2000’s highly rigid body and frame are major contributors to its excellent handling characteristics. In fact, the S2000 exhibits bending and torsional rigidity (especially important for good handling) better than many closed-top sports cars.

Designing such a strong structure for the S2000 posed additional challenges, because open- topped vehicles have inherently less bending and torsional rigidity. This problem can best be illustrated by removing the lid of a shoe box, and then twisting both its ends in opposite directions. The box twists easily. However, if you repeat the operation with the top in place, you immediately notice how much stiffer the enclosed box has become.

Similarly, unless an open-topped vehicle’s body and frame are reinforced, cornering grip and handling control will be compromised. A torsionally weak frame will store, then release suspension energy in an uncontrolled manner, resulting in less tire contact with the road and less steering precision and control.

In order to achieve the desired level of frame stiffness, Honda engineers designed a new monocoque body with a centralized backbone frame for the S2000. This backbone tunnel is enclosed by the floor and runs down the centre of the cockpit, between the driver’s and passenger’s seat. Large side sills provide additional strength. Diagonally braced front and rear bulkheads contribute to tying the frame members together into a strong beam-like structure that resists bending and torsional forces. Crossmembers running under the driver’s and passenger’s seat add additional stiffness.

The front and rear portions of the central frame and the side sills tie into diagonal braces (X- braces) at the rear of the cockpit and at the front cowl. These X-members connect directly to the front and rear suspension subframes.

Despite the front subframe’s light weight and compactness, its overall lateral rigidity is quite high. In addition, the engine mount structure has been designed so as to minimize the effect of lateral movement in the frame, when cornering.

The rear subframe is a three-dimensional structure consisting of hollow steel pipes that connect the rear side members and floor tunnel to the upper and lower arms of the rear suspension. A deep-section, rear crossmember ties the beams together and anchors the rear of the differential.

COMPACT (IN-WHEEL) 4-WHEEL DOUBLE WISHBONE SUSPENSION The 4-wheel, double wishbone suspension system used on the S2000 contributes greatly to its exceptional handling. The system consists of upper and lower wishbone arms at each wheel, with coil-over spring/damper units and anti-roll bars.

The system boasts many features found on road-racing suspension systems, including a compact layout, highly rigid construction, minimal unsprung weight, a low centre of gravity and ideal geometry.

The entire S2000 suspension system is very space-efficient–Honda calls it an "in-wheel" suspension (the same design is used on the NSX). The S2000 "in-wheel" system contributes to assuring higher rigidity, as well as allowing for a low hoodline.

The suspension’s ductile iron wishbone arms are connected to the body via special rubber bushings, designed to minimize vibration without compromising suspension rigidity.

Neutral cornering response can be improved through increased roll stiffness and quicker weight transfer. The stabilizer bar’s effectiveness, and thus roll stiffness is increased here

2005 Honda S2000 5 through the adoption of ball-jointed lower arms. At the rear, changes in lateral force, as tread (track) varies with suspension movement and the accompanying jacking effect, are used to increase weight-transfer speed and aid in neutral cornering power pickup.

Wheel Alignment Values: Front: o Toe Angle: 0º o Camber Angle: -0º 30’ o Caster Angle: 6º

Rear: o Toe Angle: 0º 17’ o Camber Angle: -1º 30’

A 26.5 mm diameter front stabilizer bar and 25.4 mm rear bar contribute to the S2000’s flat cornering and enhanced steering linearity. The bars connect to their respective suspension arms via ball-jointed links.

The rear dampers, which feature large remote reservoirs, are attached to the lower wishbones, leaving more space available for the folding top and space-saver spare tire.

MONO-TUBE SHOCK ABSORBERS The S2000’s mono-tube shock absorbers help minimize body roll and contribute to rapid weight transfer, resulting in more neutral cornering behaviour and improved power transfer characteristics. They are also less harsh and better damp body vibration, which gives the chassis a more rigid feel.

HIGH-PERFORMANCE, 4-WHEEL DISC BRAKING SYSTEM Honda engineers designed the S2000’s brake system to deliver braking performance consistent with the vehicle’s other high-performance capabilities. In addition, they wanted the system to be very direct, with a firm pedal feel that enhanced the driver’s braking control.

The heart of the system is its four large disc brakes. Front rotor diameter is 300 mm and the rear diameter is 282 mm. The front rotors are also vented for added cooling, while their rear discs are solid. Brake material is cast iron.

The brake calipers are large, highly rigid, cast-iron units. Front piston diameter is 54 mm, and the rear pistons are 40 mm in diameter. The pad material is a high-performance, fade- resistant type. Brake-pad area is 42 square centimeters for the front pads and 27.9 square centimeters for the rear-brake pads.

A 198.1 mm, single-vacuum servo-assist unit is used because it offers the best balance between pedal feel (stiffness) and assist. Braking bias–front-to-rear–has also been optimized so that the front and rear brakes operate at maximum braking efficiency during heavy braking.

HONDA-DESIGNED 3-CHANNEL ABS The anti-lock braking system (ABS) is a new compact type that incorporates the solenoid valve, motor and ECU into the modulator body, thereby saving both space and weight.

The ABS system is a four-sensor, three-channel system with a speed sensor located at each wheel. There is a separate channel for each front wheel and the rear wheels share a common third channel. This is a "select-low" system, meaning the system controls both rear-wheel slave cylinders together when it senses incipient wheel lockup in either wheel.

Increasing the memory capacity of the system’s Electronic Control Unit (ECU) allows the system to better estimate vehicle speed, which gives it better control in the lower-slip range. This contributes to superior braking efficiency and stability.

2005 Honda S2000 6 WHEELS AND TIRES The S2000 features Summer Performance 215/45R17 front tires, mounted on 17" x 7.0" JJ aluminum-alloy wheels.

The rear tires are Summer Performance 245/40R 17 and are mounted on 17" x 8" JJ aluminum-alloy wheels.

A space-saver spare tire is in the trunk.

ELECTRIC POWER STEERING (EPS) SYSTEM The S2000 uses an electrically assisted power steering system in place of the more commonly used hydraulically assisted system. The electric system (first used on the high-performance Acura NSX), offers numerous advantages. The S2000 system is simpler and more compact (there is no need for a pump and hoses) and the power loss is minimized. The system’s compactness and simplicity also offer more design freedom. The system is also smoother and more responsive to driver input, and more communicative to the driver.

The system consists of a toothed rack and pinion gear, with a microprocessor-controlled, coaxial electric motor assisting the rack. The microprocessor senses vehicle speed and steering torque and is programmed to vary boost accordingly, providing more boost at low speeds and progressively less at higher speeds. Failure warning, self-diagnosis and self- protection functions are built into the system.

Steering kingpin and caster angles have been optimized for better steering feel, and a quick 14.9-to-1 gear ratio also contributes to the car’s nimble and direct steering characteristics.

2005 Honda S2000 : Interior

INTERIOR - OVERVIEW As with the S2000’s exterior, the central design theme of the roadster’s interior is performance. Honda engineers designed the interior to contribute to what they call an "interfusion" between the driver and the car.

The conceptual model for the S2000 interior is a modern Formula 1 car’s cockpit. Outward visibility, simplicity of controls, control feel, comfort – both machines have these needs in common.

Before production, the interior design was extensively tested, including wind-tunnel testing and over 32,000 kms of real-world driving in what Honda calls the maturing phase of the design. It is during this phase of development that details such as control placement, seating and driver visibility are finalized.

HONDA S2000 INTERIOR FEATURES o Control layout o Excellent outward visibility o Dual airbags (SRS) o Air conditioning o Micron air-filtration system o AM/FM stereo CD player (with clock) o Power windows o Power door locks o Power mirrors o Cruise control o Digital instrument panel o Leather-trimmed seats o Centre console storage compartments w/lock o Beverage holder o 12-volt power outlet

2005 Honda S2000 7 o 3-point seat belts with pretensioner and load limiter o Remote-operated audio controls o Immobilizer Theft-Deterrent System o Engine start button o Keyless entry system o Floor mats

DRIVER-ORIENTED INTERIOR The S2000’s driver-oriented interior is stylistically restrained and functional. The contoured seats are upholstered in leather, and have a perforated texture that helps the material breathe. Legroom is ample and the seatback’s side bolsters extend all the way up to the shoulder for good lateral support when cornering. The head restraints are fixed and feature an open design that contributes to the overall open feel of the cockpit.

Seat adjustment is manual and includes adjustments for fore and aft position and seatback angle. A padded and carpeted central console separates the seats.

The sculpted door inserts are upholstered in leather and include an armrest, grab handle, door latch, power window and door-lock controls. The driver’s side door includes power-mirror controls.

The instrument panel curves around each side of the central instrument pod. Smaller pod wings house controls for heating, ventilation, air conditioning, audio, cruise control, the engine start button and the air outlets.

The foot pedals feature a textured-metal finish reminiscent of the pedals found in race cars, and are positioned for optimal heel-and-toe operation.

The padded 3-spoke steering wheel features the cruise control switches. The AM/FM stereo and CD player sit beneath the centre of the instrument panel, at the forward end of the centre console. A flip-down cover hides the radio controls from view, and from the elements. A clock is part of the radio.

The 6-speed shifter, emergency flasher switch, hand brake lever and power-operated soft-top switch are housed in the central console, along with a beverage holder and a pocket for small items, such as change. A compartment located on the rear bulkhead, between the driver’s and passenger’s shoulders, features a hinged, locking cover and functions as a glove compartment. Two lockable storage units are located behind the driver’s and passenger’s seats.

RACE-CAR-TYPE DIGITAL DISPLAY The S2000 features a digital instrument panel reminiscent of the displays used in modern racing cars. The display features a large, semicircular bar-type tachometer divided into eighty- five 100-rpm increments. The tachometer flashes red when the engine redline is reached. A highly visible digital speedometer readout is below the tachometer display, as well as readouts for coolant temperature, fuel level, trip and cumulative mileage odometers and warning lights for SRS, oil pressure, the Immobilizer Theft-Deterrent System and ABS.

ELECTRONICALLY CONTROLLED HEATING AND AIR-CONDITIONING SYSTEM The various functions of the heating and air-conditioning system are electronically controlled and actuated by the heater and airflow controls. The heater outlets at knee level and the centre outlet in the instrument panel help extend comfort when the top is down in cool weather.

The air-conditioning-system evaporator is a new design that takes up less space, is more efficient at transferring heat and has greater corrosion resistance.

MICRON AIR-FILTRATION SYSTEM

2005 Honda S2000 8 The S2000 air-conditioning system features a replaceable micron air filter capable of filtering particulate matter from 8.0 microns (the size of most pollen) down to as small as 0.3 microns (diesel emissions). 2005 Honda S2000 : Powertrain

POWERTRAIN - OVERVIEW The S2000 powertrain uses a front-engine/rear-wheel-drive layout. The longitudinally mounted engine is mated to a 6-speed, close-ratio manual transmission. A propeller shaft carries the output of the transmission to a frame-mounted limited-slip differential. The differential drives the rear wheels via separate axle shafts.

The 2.2-litre, aluminum-alloy, inline 4-cylinder S2000 engine produces 240 hp @ 7800 rpm and 162 lb.-ft. of torque @ 6500 rpm. The cylinder head is also made of aluminum alloy and features dual overhead camshafts, 4 valves per cylinder and VTEC (Honda's variable valve- timing system) on both the intake and exhaust valves. Fuel delivery is via Honda's sequential, Multi-Point Programmed Fuel Injection (PGM-FI) and the ignition system is a high-voltage, computer-controlled direct type with individual spark coils for each cylinder. In addition, the engine's exhaust emissions are so low that the S2000 is designed to meet (LEV) standards.

The following are the main features of the S2000 drivetrain: o 2.2-litre VTEC Engine o 8000 rpm Red Line o 240 hp @ 7800 rpm o 162 lb.-ft. of torque @ 6500 rpm o 0-100 kph acceleration in less than 6 seconds o Compact, lightweight engine design aids in ideal (50/50) weight distribution o FRM (Fiber-Reinforced Metal) cylinder liners o 87 mm bore X 90.7 mm stroke contributes to high-rpm operation o Rigid aluminum (ladder-type) main bearing support, with cast-iron bearing inserts, enhances engine durability o Lightweight forged-aluminum pistons and heat-treated (carburized), forged-steel connecting rods add durability o Full-floating piston pins eliminate piston noise during warm-up o High-volume oil pump with silent chain drive o Compact, high-efficiency oil cooler o Cast-aluminum oil pan helps minimize engine noise and enhances oil cooling o 11.1:1 compression ratio o Compact, DOHC VTEC cylinder head and valvetrain o Lightweight, MIM (Metal-Injection Molded), sintered-steel rocker arms o Low-friction roller-bearing cam-followers o Compact, 2-stage cam-drive with silent chain, scissors gears and fully automatic tensioner o Hollow camshafts function as lubrication path for VTEC valvetrain o Sequential, Multi-Point Programmed Fuel Injection (PGM-FI) o Intake system with straight inlet ports and low-back pressure exhaust system o Electric-motor-driven, multi-port secondary air-assist injection system helps lower hydrocarbon emissions o Designed to meet stringent Low-Emission Vehicle (LEV) standards o Compact engine ancillary drive system uses a serpentine drive belt with automatic tensioner o Compact engine ancillaries, such as air-conditioning compressor and water pump, save weight and take up less space o Direct-ignition system with long-lasting platinum-tipped spark plugs o Low back pressure, metal-honeycomb catalytic converter o Longitudinally mounted 6-speed, close-ratio manual transmission o Transmission lubrication pump enhances durability o Reduced shift effort from double-cone synchronizers on first, third and fourth gears, and triple-cone synchronizers on second gear

2005 Honda S2000 9 o Short-throw, direct shift linkage o Compact pull-type clutch mechanism and high-performance clutch o Low-mass flywheel o Propeller shaft uses constant-velocity joints instead of U-joints o Torsen limited-slip differential o Highly rigid axle shafts utilize stronger flanged ends in place of splines

S2000 ENGINE DESIGN Honda engineers designed the S2000 with an ideal 50/50 weight distribution, a low yaw moment and a low centre of gravity. They accomplished this by placing the engine and drivetrain as far back in the chassis as possible, and by designing the engine to be very compact. In addition, many of the engine’s components have been designed to be as compact and as lightweight as possible.

COMPACT HIGH-OUTPUT ENGINE BLOCK The S2000 engine block is a one-piece, open-deck aluminum-alloy die casting. Of special note are the block’s FRM (Fiber-Reinforced Metal) cylinder liners cast integral with the block. FRM is a composite material consisting of carbon fibers embedded in an aluminum oxide matrix (aluminum oxide is a ceramic material used for spark-plug insulators). As a cylinder lining, FRM offers several advantages over conventional ferrous-metal liners, including lower weight, faster heat transfer and a greater resistance to wear.

Cylinder bore is 87 mm and the stroke is 90.7 mm. This results in a nearly "square" bore- stroke ratio that facilitates high-rpm performance and still exhibits good torque characteristics at lower rpm.

FORGED-ALUMINUM PISTONS The high-revving nature of the S2000 engine necessitated the use of special high-strength, lightweight forged-aluminum pistons (the first use of this material in a Honda production automobile). The piston’s minimal skirt area contributes to friction reduction.

The carburized connecting rods and crankshaft, also steel forgings, are heat-treated for added toughness.

LADDER-TYPE MAIN-BEARING CARRIER The S2000 engine’s large ladder-type, cast-aluminum stiffener, with cast-iron bearing inserts, runs the full length and width of the lower engine block and contributes considerably to engine rigidity. The carrier also incorporates oil passages for the main bearings.

CAST-ALUMINUM OIL PAN A cast-aluminum oil pan bolts to the bottom of the main-bearing carrier. The pan is finned to help dissipate heat, and the use of an aluminum casting instead of a steel stamping provides additional rigidity to the engine and transmission. In addition, cast-aluminum radiates less engine noise than a customary steel-stamped pan.

DOHC VTEC CYLINDER HEAD The S2000 engine’s DOHC cylinder head is a highly compact design, and like the engine block, is an aluminum-alloy die casting. The combustion chambers are a pent-roof shape, with four valves for optimum high-rpm airflow. A narrow (51-degree) included angle between the intake and exhaust valves helps to concentrate air and fuel around the central spark plug, resulting in more complete combustion and greater efficiency.

The valve springs are a single-element, round-profile type whose high-rpm design borrows heavily from Honda’s racing-engine building experience.

VTEC VARIABLE VALVE TIMING

2005 Honda S2000 10 The S2000 engine uses a performance version of Honda’s innovative variable valve-timing system on both the intake and exhaust valves (VTEC stands for Variable Valve-Timing and Lift Electronic Control). VTEC maximizes the S2000 engine’s volumetric efficiency–packing the maximum amount of air and fuel into the combustion chamber on each intake stroke and expelling the maximum amount of exhaust gases on the exhaust stroke.

VTEC works by varying valve timing and lift to compensate for the time delay and out-of- phase arrival of the air-fuel charge at the intake valve. Ideally, the valves should remain open for a short duration at low engine speeds and for a longer duration at high engine speeds–and that is precisely how VTEC works.

LOW- AND MEDIUM-SPEED OPERATION In the S2000 VTEC engine, each intake and exhaust valve uses two different cam-lobe profiles: one for low engine speeds and a second for high engine speeds. From idle to around 6000 rpm, the two intake and exhaust valve cam followers at each cylinder are actuated by low-rpm cam lobes. Their short duration and low lift ensures good cylinder-filling at low engine speeds.

HIGH-SPEED OPERATION At around 6000 rpm (depending on throttle position), an electronic control unit commands a spool valve to open and send oil pressure to pins in the cam followers. Under pressure, the pins lock the two intake-valve followers and the two exhaust-valve followers to a third follower. Until this moment, this third follower has been independently following the contour of a separate high-lift, long-duration cam lobe. Now the valves are actuated by the third follower and more closely match the induction and exhaust timing required for optimum torque at high engine speeds.

COMPACT CAMSHAFT DRIVE The S2000 engine’s dual overhead camshafts feature space-efficient cam-drive consisting of a crankshaft-driven, silent-chain primary drive and a geared-secondary drive. The chain, along with a chain guide and an automatic tensioner, is located in an enclosed gallery at the front of the engine block.

The primary chain turns an idler gear at its upper end, which drives the second stage–the intake and exhaust camshaft gears. The camshaft gears are smaller in diameter than conventional toothed sprockets, which allow the camshafts to be placed closer together, further saving space. Geared drives are widely used in racing engines because of their dependability and greater timing accuracy at high rpm.

Each camshaft gear is a split (scissors) type, consisting of two concentric, spring-loaded gears, set at a slight angle from each other. When engaging the teeth of the idler gear, the spring- loaded split teeth of the cam gear take up any backlash, ensuring smoother, quieter operation. LIGHTWEIGHT VTEC CAM FOLLOWERS Because of the high-rpm nature of the S2000 engine and the need to save space, Honda engineers devised a new VTEC cam follower system. The central element in this newest DOHC VTEC system is the development of a new roller-type, coaxial VTEC cam follower. The adoption of a roller in the area in contact with the camshafts helps further reduce friction losses. At the same time, a reduced inertial moment has been made possible by integrating the sliding pin used to operate the cam profile switch into the roller structure.

A more precise metal-injection molding process has been adopted in order to obtain the higher degree of rocker-arm finish required by the roller-type, coaxial VTEC design. These innovations have reduced valvetrain friction by approximately 70 percent, and improved engine torque characteristics by allowing the valvetrain changeover point to be set at a relatively low 5850 rpm. This allows the use of the high-performance, high-lift cam profile over an extended range of engine speeds, so engine response and power output remain high all the way to its 8000 rpm redline.

2005 Honda S2000 11 The two overhead camshafts are hollow in order to supply oil to the cam lobes for lubrication. This eliminates the need for a separate oil line and nozzles, which helps to simplify the cylinder-head lubrication system.

COAXIAL ROLLER-BEARING CAM FOLLOWERS The cam followers use roller-element bearings to help minimize friction. An additional space efficiency was realized by placing these roller elements so that they are concentric with the hydraulic pistons of the VTEC system.

POWDERED-METAL, INJECTION-MOLDED, SINTERED STEEL-ALLOY CAM FOLLOWERS Honda engineers used a powdered-metal injection-molding process to make the S2000 engine’s VTEC cam followers, in place of the older, more complicated and time-consuming method of casting and machining them. In this new process, powdered steel alloy is mixed with a binder that allows it to be injected into a mold, in much the same way that plastic items are injection-molded. The part is then removed from the mold and the binder is removed by heating. The rocker arm is then sintered, which involves heating the metal to just under its melting point in a special furnace so that the steel particles weld together. Complex shapes such as the S2000 engine’s cam followers are more easily produced by metal injection- molding, and they require little additional finishing.

EXTERNALLY MOUNTED OIL PUMP To help minimize engine length, Honda engineers placed the oil pump on the side of the engine block instead of its usual location at the front of the crankshaft. This new placement improves engine compactness, and the pump scavenges oil more efficiently.

Additionally, the oil pump’s lower placement helps pressurize the lubrication system more quickly during engine startup.

The oil pump itself also is a new, more compact design that uses a smaller, high-speed rotor and suction-pickup ports on both sides of the pump body. The new design supplies a greater volume of oil to the engine at all engine speeds. The oil pump is driven via a silent chain connected to the crankshaft.

COMPACT ENGINE ANCILLARY DRIVE The system for the engine ancillaries, such as the alternator, air-conditioning compressor and water pump, can take up considerable space at the front of the engine. So Honda engineers moved them to a new location at the side of the engine block (a practice commonly used on racing engines) and designed a new, compact drive system that uses both sides of a serpentine belt. An automatic tensioner is built into the drive system.

In addition, many of the engine’s ancillary components have been designed to be more compact and easier to manufacture. For example, the water-pump housing incorporates the thermostat and the alternator-mounting bracket into one unit. The oil cooler is a new water- cooled design, and the air-conditioning compressor uses a smaller diameter clutch and armature.

DIRECT-IGNITION SYSTEM In place of a distributor, the S2000 engine uses a computer-controlled direct-ignition system, with individual high-voltage coils located at each spark plug. The spark plugs have non-fouling platinum tips for longer life.

Timing data for the ignition system is supplied to the engine’s Electronic Control Module by a pair of TDC (Top-Dead Center) sensors–one located on each camshaft–and a toothed-wheel crank-angle sensor located on the crankshaft. The Electronic Control Module automatically adjusts engine spark timing and dwell based on throttle opening, engine rpm, knock-sensor data, etc.

INTEGRATED AIR-INTAKE SYSTEM

2005 Honda S2000 12 In order to meet the S2000 engine’s performance requirements, the intake system has to be capable of moving a large volume of air. In order to achieve this, Honda engineers placed the entire intake system in the space in front of the engine (made possible by the engine’s extreme rearward location in the engine compartment). In this location the system can draw cool air directly from in front of the main-forward engine-compartment bulkhead. Since the system does not sit on top of the engine, it also allows for a lower hood height and better forward visibility.

The actual intake system consists of a large, 5.5-litre expansion chamber, a low-resistance, conical axial-flow air filter and a main resonator (intake-noise attenuator). From the air cleaner, intake air flows in a short, direct path to four large-section, tuned intake runners. The runners, along with the cylinder-head intake ports, have been carefully angled in order to provide the shortest, straightest airflow path into each cylinder.

MULTI-POINT PROGRAMMED FUEL INJECTION The fuel-induction system uses Honda Multi-Point Programmed Fuel Injection (PGM-FI). PGM- FI is a timed, sequential system with sensors for throttle position, coolant temperature, crankshaft angle, intake-manifold pressure, atmospheric pressure, intake-air temperature, vehicle speed and exhaust-gas oxygen content. Information from these sensors is fed to an Electronic Control Module, which then decides when to activate each injector. PGM-FI can alter fuel delivery to match the engine’s needs under varying environmental and engine-load conditions.

LOW-EMISSION VEHICLE (LEV) TECHNOLOGY Honda engineers designed the S2000 engine to have a high power output and also to be a Low-Emission Vehicle (LEV) engine. In order to accomplish this goal, they installed a new high-flow, metallic honeycomb catalyst and new secondary air-injection system.

An ECM-controlled electric air pump feeds fresh air into the exhaust secondary air-injection system. This allows for very quick heating of the catalytic converter and low exhaust back pressure.

METALLIC HONEYCOMB CATALYST The S2000 exhaust system uses a new type of thin-walled, low-heat radiating metal honeycomb catalytic converter in place of the more traditional ceramic unit. This new design not only increases the exhaust-gas processing surface area, but also promotes a quick rise in temperature that greatly reduces hydrocarbon emissions during engine warm-up. The catalyst’s low back pressure also contributes to better engine performance. The catalyst is also a simpler design, with fewer parts than previous designs.

LOW-RESTRICTION EXHAUST SYSTEM The S2000’s engine features a low-restriction, high-efficiency exhaust system. The manifold uses large-diameter stainless-steel tubing, and is a 4-into-2-into-1 design that promotes efficient gas flow. A pre-chamber and two main silencers that utilize a "U-turn" pipe arrangement further reduce back pressure.

FLOATING EXHAUST-MANIFOLD COVER The exhaust-manifold heat shield is held in place by a metal strap that completely surrounds the manifold. Alumina insulators attached to the back of the cover help minimize vibration and noise transmission.

6-SPEED MANUAL TRANSMISSION - OVERVIEW Honda engineers designed an entirely new close-ratio, 6-speed manual transmission for the S2000. A limited-slip differential was chosen to ensure continuous application of power to the rear wheels, especially when cornering. The transmission and entire drivetrain are designed to be highly rigid and as compact and lightweight as possible, making the vehicle more responsive to driver input and increasing the driver’s enjoyment and feel for the car.

2005 Honda S2000 13 LONGITUDINALLY MOUNTED 6-SPEED MANUAL TRANSMISSION

In the S2000 transmission, all six speeds and reverse are on two parallel shafts. Both transmission shafts are coupled at the output end, a design feature borrowed from Honda’s front-wheel-drive transmissions. This reduces the load on the gear synchronizers by as much as 40 percent. Shift loads are also reduced, making shifting easier.

The use of double-cone synchronizers for first, third and fourth gears, and triple-cone synchronizers for second gear, helps reduce shift effort. Reverse gear uses single-cone synchronizers for smoother shifting and quieter operation.

TRANSMISSION GEAR RATIOS o First Gear: 3.133 o Second Gear: 2.045 o Third Gear: 1.481 o Fourth Gear: 1.161 o Fifth Gear: 0.943 o Sixth Gear: 0.763 o Reverse Gear: 2.800 o Primary Gear Reduction: 1.160 o Final Drive: 4.1:1

SHORT-STROKE, DIRECT SHIFT LINKAGE

The transmission shift linkage is mounted on the top of the transmission case, helping to eliminate play in the linkage and provide optimum feel when changing gears. Shift throws are short and direct. Shift detents and lateral-spring pressure are set so that the shift-lever neutral position lies on the 3rd-gear/4th-gear axis.

The shift lever is aluminum alloy and floats in a rubber mounting that absorbs vibration. Reverse-gear lockout is a mechanical type, which can be released by pressing the shift lever to the side.

SEPARATE LUBRICATION PUMP ENHANCES DURABILITY Racing experience taught Honda engineers that high-performance transmissions need a separate lubrication system, so the S2000 manual transmission has its own lubrication pump, driven off the transmission secondary gear. The pump provides positive and reliable lubrication, regardless of G-loading, and helps to prolong gear and synchronizer life.

LOW-MASS POWERTRAIN When cornering a high-performance, front-engine, rear-wheel-drive roadster, throttle input can be used as a means of fine-tuning vehicle control. For this reason, Honda engineers wanted to keep the S2000 powertrain’s entire rotational mass to a minimum, thereby minimizing inertia, and the response time between driver input and vehicle reaction. In order to accomplish this, many components, such as the clutch, flywheel, propeller shaft, axle shafts and constant-velocity joints have had weight carefully removed.

COMPACT HEAVY-DUTY, PULL-TYPE CLUTCH In addition to reducing the size and mass of the engine flywheel and transmission gears, Honda engineers adopted a pull-type clutch mechanism and reinforced friction materials better suited to the high-rpm nature of the powertrain.

LOW-VIBRATION PROPELLER SHAFT The propeller shaft that takes power to the rear differential in the S2000 is a strong, one-piece design. To reduce noise and vibration from the shaft, Honda engineers specified sliding, constant-velocity joints at both ends, instead of the more common U-joints. Constant-velocity joints also transmit power more uniformly over a range of angles.

LIMITED-SLIP DIFFERENTIAL

2005 Honda S2000 1 4 The Torsen limited-slip differential (clutchless type) used in the S2000 is specifically adapted for high power output and automatically transmits drive torque to the wheel and tire with the most traction, thereby limiting wheel spin.

ONE-PIECE, HIGHLY RIGID AXLE SHAFTS Power is transmitted from the differential to the rear wheels via a set of rigid, one-piece axle shafts. The shafts’ increased level of rigidity improves the powertrain’s response to throttle input.

2005 Honda S2000 : Safety

IMMOBILIZER THEFT-DETERRENT SYSTEM An Immobilizer Theft-Deterrent System is standard on the S2000. The ignition key has a built- in transponder, which, when removed, immobilizes the engine fuel injection and ignition so the engine cannot be started. When the key is inserted, a radio signal from the ECU (Electronic Control Unit) is sent to the transponder. If the code in the key and the code in the ECU agree, then the ECU allows the engine to be started.

The key needs no batteries, as it receives what little energy it needs via the ignition/steering- lock unit that functions as a transmitter/receiver antenna. An indicator lamp on the instrument panel lets the driver know that the immobilizer system has accepted the key. An immobilizer sticker is affixed to the window.

S2000 COCKPIT SAFETY SYSTEMS The driver’s and passenger’s SRS (Supplemental Restraint System) both use a new compact airbag that fits the S2000’s small steering wheel and instrument panel.

The lower anchor points for the S2000’s 3-point, auto-locking seat belts are at the side sill and seat. The upper anchor bolts to a bracket mounted directly on the S2000’s rollbars.

The S2000 body and the highly rigid high X-bone frame’s central tunnel, straight front and rear side members, side sills and floor frame are designed to form a strong three-point support structure that distributes loads evenly. The resulting body structure boasts the rigidity and passenger protection of a closed-top vehicle in full-frontal and rear impacts. Head-injury protection is built into the interior, and side-impact protection is built into the doors, door pads, side sills and floor of the cockpit.

Even though open-topped cars are exempted, the S2000 meets the federal standard for occupant protection in a rollover accident. The driver’s and passenger’s roll bars are made of 38.1 mm diameter high-strength steel pipe with a 2.03 mm wall thickness, and tie directly into the frame. Additional protection is provided by reinforced door pillars, windshield posts and the windshield frame.

In addition, the S2000 incorporates pedestrian injury-reducing technology in the form of collapsible hood hinges and windshieldwiper pivots, designed to help minimize the chances of head injury to a pedestrian in a collision.

2005 Honda S2000 15