good info I didnt know this

2004 Honda Press Releases - it seems many got cut off when the site migration occured.

Oct 6 2003 - Honda S2000 Receives Enhanced Power and Improved Handling for 2004 - http://www.honda.com/newsandviews/ar...d=200707031516

http://www.hondanews.com/channels/ho...ta?query=s2000

2004 Honda S2000 Prices and EPA Data

Text Only 2004S2000Pricing.doc Add to Basket Remove from Basket Printer Friendly
10/06/2003 - Torrance, Calif.

EPA
Model

Transmission

MSRP

City/Hwy.
.


S2000

6-Speed Manual

$32,800

20/25
.
Destination and Handling Charge is $515 per vehicle.

http://www.hondanews.com/channels/ho...rt?query=s2000

2004 Honda S2000 -- Introduction Part 1

Introduction

Overview

The Honda S2000 is a high-performance, 2-seat, open-topped roadster with an advanced front-engine, rear-wheel-drive sports car configuration. Introduced in 2000 as a commemoration of Honda’s 50th anniversary, the S2000 incorporates many of the lessons learned in the company’s five decades of building and racing cars and motorcycles. Its original concept was to be a true sports car that could serve as both a practical and fun daily driver and a highly capable weekend track racer.

For its 2004 redesign, Honda engineers built on those ideals and elevated the S2000 to a higher class by strengthening the all-around performance, enhancing the interior and giving the exterior a subtly bolder appearance. The net gain is an S2000 that is simultaneously an improved track car and an improved daily driver.

The 2004 S2000 benefits from the following major enhancements:

* Larger displacement 2.2-liter engine (240 horsepower @ 7800 rpm and 162 lb.-ft. of torque @ 6500 (replaces 240 hp @ 8300 rpm and 153 ft.-lbs. @ 7500 rpm )
* Larger wheels and tires (17-inch)
* Revised suspension tuning
* Revised transmission gear ratios and improved shift feeling
* Bolder front and rear exterior styling
* Freshened interior design
* New options including XM Satellite Radio™ and headrest speakers

On the track, the 2004 S2000 accelerates with increased authority and more pull through corners with a broadened powerband that comes on sooner and stronger. The new suspension tuning enhances vehicle control qualities at the limit, while minimizing bump steer effects from road disturbances. Larger 17-inch wheels and tires provide more grip and maximize the suspension tuning.

From 1000 rpm to 8000 rpm, available torque and horsepower increase between 6- and 10-percent. Additionally, useful power for high performance acceleration begins at about 3000 rpm compared to about 6000 rpm on the 2000 – 2003 models. This performance improvement at the lower rpm ranges can be attributed to the displacement increase, revised valvetrain tuning and the lower gear ratios on gears one through four that help magnify the engine performance gains.

On the street, the 2004 S2000 transmits less ride harshness, while the enhanced powerband reduces the need to shift as often in certain circumstances. Interior comfort also improves with more elbow and shoulder room, and the center console now has two cupholders, a storage tray and more utility.

The sum of the entire series of changes produces significant results on a platform that sets an industry standard for precision and performance. In short, the 2004 S2000 sports a new muscular feel, refined handling and enhanced interior comfort with better convenience features while maintaining its focus as a true high performance sports car.

2004 S2000 Improvements

Performance and Handling

* Dynamic acceleration potential increased
* Transmission shifter direct feel increased
* High-speed stability enhanced
* At-the-limit performance increased with more gradual fall-off
* Sensitivity to disturbances decreased (less bump steer)
* Steering feedback enhanced
* Brake pedal dynamic feel enhanced

Comfort and Convenience

* Interior space increased
* Interior storage functionality increased
* Optional audio features added

2004 Honda S2000 vs. 2003 Honda S2000



2004 2003 Change/Notes
Powertrain
Engine

2.2-liter DOHC VTEC

2.0-liter DOHC VTEC

+ 0.2 liters, attributable to engine stroke change
Horsepower

240 @ 7800 rpm

240 @ 8300 rpm

+ 0 hp @ -500 rpm, same peak horsepower with overall
powerband characteristics strengthened 4% to 10% between
1000 -8000 rpm
Torque (lbs.-ft.)

162 @ 6500 rpm

153 @ 7500 rpm

+9 lb.-ft. @ -1000 rpm with improved powerband
characteristics strengthened between 4% and 10% between
1000-8000 rpm. Max torque increases 5%.
Rev Limit (fuel cutoff)

8200

9000

Piston travel configuration decreases rpm limit by 9%
because of piston speed increase.
Compression Ratio

11.1:1

11.0:1

+0.1:1
Transmission Ratios

Reconfigured
-

Gears 1-4 = 4% lower for performance

Gear 5 = 1% lower

Gear 6 = 2% higher
Suspension
Wheels (inches)

Front: 17×7

Rear: 17×8.5

Front: 16×6.5

Rear: 16×7.5

Front: + 1×0.5 (new wheel design)

Rear: + 1×1 (new wheel design)
Tires

Front: P215/45R17

Rear: P245/40R17

Front: P205/55R16

Rear: P225/50R16

Larger contact patch
Springs

New Tuning
-

Front: Increased spring rate 6.7%

Rear: Decreased spring rate 10%
Shock Absorbers

New Tuning
-

Tuned for new suspension settings
Stabilizer Bars (mm)

Front: 26.5x t4.5

Rear: 25.4 x t4.5

Front: 26.5x t4.5

Rear: 27.2 x t4.5

Front: Same

Rear: -1.8 × 0
Ride Height

Non-Load: 5.1

Full-Load: 4.2

Non-Load: 5.1

Full-Load: 4.2

No Change
Body Aerodynamics

Enhanced
-

5% improvement in Cd from new front bumper design
Body Rigidity

Enhanced
-

Rigidity increased
Front Bumper

Redesigned
-

New bumper and new triple-beam headlight designs
Rear Bumper

Redesigned
-

New bumper, triple beam LED taillights and oval exhaust
tips designs
Weight (lbs.)

2835

2811

+24, attributable to body rigidity increase and new
wheels and tires
Exterior Dimensions

L x W x H (inches)

162.2 × 68.9 × 50.0

162.2 × 68.9 × 50.0

0 × 0 × 0
Interior
Shoulder Room (in.)

50.7

48.4

+0.9 (20mm)
Interior Console

Redesigned
-

New console with two cupholders (+1) and storage
compartment, new trim pieces
Interior Doors

Redesigned
-

Increased elbow and shoulder room, new speaker
enclosures
Steering Wheel

Minor update
-

New Honda emblem
Radio

New design
-

XM Satellite Radio available and optional headrest
speakers added

http://www.hondanews.com/channels/ho...-2?query=s2000


2004 Honda S2000 -- Introduction Part 2

The 2004 S2000 engine has been re-designed and
displacement
increased by 0.2 liters through lengthening the stroke of piston
travel. The 2.2-liter, DOHC VTEC 4-cylinder engine produces 240
horsepower and 162 lb.-ft. of torque while meeting California’s
Low-Emission Vehicle (LEV) standards. Honda’s innovative
VTEC
advanced variable valve-timing system, operates the S2000
engine’s 16
valves (4 per cylinder) in both intake and exhaust modes. This
system
is compact and tailored to the high-output, high-rpm operating
characteristics of the S2000 engine.

A revised 6-speed, manual transmission provides lower
gear ratios
on gears one through five, and a higher sixth speed gear for
highway
cruising The transmission is a compact design and features a
direct
shift linkage with class-leading feel and short throws. A Torsen
limited-slip differential smoothly delivers power to the rear
wheels,
regardless of traction conditions. The S2000 engine and
transmission
are capable of accelerating the S2000 from 0-60 mph in less
than six
seconds.

Honda’s racing experience is also evident in the S2000’s
responsive handling. The chassis has an ideal 50/50 weight
distribution, and the body and frame are a hybrid
monocoque-frame
structure that forms a rigid, flex-free platform for the S2000’s
in-wheel double wishbone suspension system, and plays an
important
role in helping the S2000 achieve its high level of safety
protection. The power steering system is a highly responsive,
electrically assisted type.

Larger front 215/45 87W and rear 245/40 91W tires are
mounted on
newly-designed 17-inch alloy wheels, and 11-inch brake discs
(vented
in front) provide excellent stopping power and brake feel. For
2004,
new brake pad material improves the pedal feel and resists
fading in
high performance driving. An anti-lock braking system is
standard.

The exterior styling of the S2000’s body is angular, modern
and
purposeful, with the 2004 model receiving bolder front end and
rear
end styling. Its long hood and flared front fenders create the
impression of lowness and mass. The nose has slightly
improved
aerodynamics for 2004 that involves re-shaping the front
bumper. High
sides reinforce the cockpit-like feel of the interior.

The interior is modern and designed with the driver’s needs
in
mind. The seats contour to provide excellent lateral support
during
aggressive turns and help minimize fatigue. Outward visibility is
unobstructed.

For 2004, controls such as the steering, brakes and clutch,
operate with a new level of precision and have an even more
direct
feel. The aluminum leather-wrapped shift knob and lever,
F1-inspired
digital instrument display and separate engine-start button serve
as
a reminder of the racing heritage of the S2000.

2004 Honda S2000 Roadster Technical Highlights

Advanced technologies used in the S2000:

* Hybrid monocoque body and “high X-bone frame” has
torsional
and bending rigidity of closed-top vehicle, without excess
weight
* Highly compact, 2.2-liter, DOHC VTEC engine produces 240
hp
and 162 lb.-ft. of torque
* Compact DOHC three-rocker VTEC variable valve-timing
system
adjusts intake and exhaust valve duration
* Coaxial, roller-bearing cam followers
* Lightweight, powdered-metal, injection-molded, sintered
steel-alloy cam followers
* Electric Power Steering system (EPS)
* F1-inspired digital instrument panel
* High-efficiency, low-back pressure, metallic-honeycomb
catalyst
* In-wheel, 4-wheel double wishbone suspension
system
* Impact-absorbing body and frame designed to help protect
the
driver and passenger in full-frontal, offset-frontal, side and
rear impacts
* 6-speed, transmission
* Forged-alloy pistons and “dummy head” honed cylinder
block
* Heat-treated, carburized forged-steel crankshaft and
connecting rods
* Nut-less connecting rods
* High-intensity discharge (HID) projector headlights
* Torque-sensing limited-slip differential
* Long-wearing FRM (Fiber-Reinforced Metal) cylinder
liners
* Compact “in-wheel” double wishbone suspension
system
* Engine meets Low-Emission Vehicle (LEV) standards

S2000 Power and Convenience Features

The S2000 has an impressive list of standard comfort and
convenience features, designed to make driving more pleasant
and
enjoyable, including high-intensity discharge (HID) projector
headlights, a power-operated convertible top that opens or
closes in
approximately six seconds, air conditioning, micron air filtration,
cruise control, an AM/FM stereo with CD player, remote-operated
audio
controls, power door locks, power windows, power heated side
mirrors,
Immobilizer Theft-Deterrent System and keyless entry for both
doors
and the trunk. For 2004, XM Satellite Radio and headrest
speakers are
available as optional.

Safety Features

The S2000 is designed to comply with various worldwide
safety
standards and boasts an extensive list of safety features,
including
3-point seat belts with load limiter and pretensioner, a compact
SRS
system for the driver and passenger, roll bars and reinforced
windshield posts, and a body and frame especially designed to
help
absorb the energy of full-frontal, offset-frontal and rear impacts.
Even the hood hinges and windshield-wiper pivots are designed
to
collapse in order to minimize head injury to pedestrians.
Anti-lock
brakes (ABS) are standard.

High-Output 2.2-Liter Engine

In order to give the S2000 an ideal 50/50 weight distribution
and
a low yaw moment, Honda engineers designed the S2000’s
2.2-liter,
240-hp, 16-valve, 4-cylinder engine to be as small and as
lightweight
as possible. The engine’s aluminum-alloy cylinder head is a
highly
efficient design and features a compact gear- and chain-drive
system
for the dual overhead camshafts. The ancillary drive system for
the
alternator, water pump and air-conditioning compressor is also
a new
space-efficient type.

The S2000 engine’s highly rigid, aluminum-alloy cylinder
block
features Honda’s long-wearing FRM (Fiber-Reinforced Metal)
cylinder
liners. The lightweight pistons are made of forged aluminum
alloy and
the forged-steel connecting rods and crankshaft are heat-treated
for
added toughness. Numerous friction-reduction techniques, such
as,
roller-bearing cam followers, special pistons and advanced
bearing
materials, are used in the engine.

A compact version of VTEC (Variable Valve Timing and
Electronic
Engine Control), Honda’s variable valve timing system, is used
on the
S2000 engine. The VTEC system optimizes torque output over
the
engine’s entire operating range, improving both driveability and
performance. The S2000’s VTEC uses compact, high-strength,
low-friction, roller-bearing cam followers.

A large-capacity, low-restriction intake system and low
back-pressure exhaust system help ensure free breathing at all
engine
speeds. The exhaust system uses a high-efficiency
metal-honeycomb
catalyst. The new catalyst, combined with the engine’s electric
pump-fed, secondary air-injection system, a direct-ignition
system
and Honda-programmed multi-point fuel injection, contributes to
the
S2000’s engine achieving its LEV status.

Six-Speed Manual Transmission

The S2000 uses a longitudinally mounted, 6-speed manual
transmission, which is built for high performance. Its gearing
ensures strong performance in every gear, and the shift linkage
is
very direct, with short, precise throws. For 2004, single carbon
synchronizers on all forward gears replace double- and
triple-cone
brass synchronizers in order to provide a more direct shift feel
and
reduce mechanical loss in the transmission. Other features of
the
S2000 drivetrain include a compact pull-type clutch with a clutch
delay system, a highly rigid, one-piece propeller shaft and rigid
axle shafts-all designed to reduce drivetrain flex to an absolute
minimum. The Torsen limited-slip differential is a highly efficient
torque-sensing, clutchless type that smoothly transfers torque to
the
wheel with the most traction, whether cornering or accelerating
in a
straight line.

In-Wheel Double Wishbone Suspension

The S2000’s 4-wheel double wishbone suspension system
is a compact
in-wheel design, similar to the type used on racing cars. At each
wheel, rigid upper and lower A-shaped wishbone links carry
suspension
loads directly to rigid subframes, attached directly to the newly
reinforced monocoque body.

For 2004, the suspension geometry has been carefully
tuned for
optimum road-holding and steering feel. Coil springs and
mono-tube,
gas-pressurized shock absorbers (remote reservoirs in the rear)
are
used at each wheel. Front and rear stabilizers (1.04 × 0.18-inch
front/1.00×0.18-inch rear) help keep body roll to a minimum.

High X-Bone Frame

Body rigidity is crucial to good handling in an open-topped
roadster, so Honda engineers designed a highly rigid
monocoque body
for the S2000 and strengthened it even more for 2004. The heart
of
the system is a large central tunnel that runs down the center of
the
cockpit. This tunnel serves as the backbone and main
load-bearing
structure for the vehicle, as well as a housing for the
transmission
and driveshaft.

The body’s high side sills, and innovative diagonal (X)
bracing at
the front and rear of the cockpit, provide additional rigidity.
Suspension and drive loads from the wheels are fed directly into
this
structure via highly rigid subframes at the front and rear of the
vehicle.

Electrically Powered Steering System

In place of a conventional hydraulic system, with its hoses,
fluid
and power drain, the S2000 uses an electrically assisted power
steering system. At low speeds, more power-steering assist is
provided, which eases maneuvering and parking. As vehicle
speed
increases, less power assist is supplied, giving the steering a
more
direct feel.

The S2000 Concept and Development

When Honda designers and engineers began work on the
S2000, they
set several overall design goals for it that would ultimately define
its nature. They wanted it to have race-car-like performance and
handling-something an enthusiast driver could use and enjoy,
even in
everyday driving situations. In addition, they wanted the S2000 to
be
a modern, socially responsible automobile, with low emissions
and a
full range of safety features.

The S2000’s roadster layout also captures the spirit of the
legendary high-performance sports cars of the past, as well as
Honda’s very first sports car, the S500 roadster. However, the
S2000
makes no attempt to be a retro sports car. It is Honda’s own
unique
interpretation of a modern sports car-with high performance,
state-of-the-art technology, comfort, style and Honda
durability.

The S2000 and the Honda Spirit

The S2000 is also intended to be a celebration of several
important aspects of the Honda Motor Company’s corporate
identity and
spirit. One aspect of that spirit can be found in the company’s
history of building sporting automobiles.

From the first S500 to the current Civic Si and the Acura NSX
supercar, Honda has always offered a dedicated performance
car.
Another aspect of the Honda spirit celebrated in the S2000 is the
company’s motor sports heritage. Honda started racing
motorcycles
internationally in the 1950s, and entered Formula 1 car racing in
the
1960s. Today, Honda still participates in the most competitive
and
prestigious levels of motor sports, including Formula 1, the Indy
Racing League and Grand Prix motorcycle racing. The S2000
incorporates many of the engineering lessons learned in five
decades
of racing.

The S2000 also represents the Honda spirit of innovation.
From the
first CVCC engine to 4-wheel steering, VTEC variable valve
timing,
and up to the current SULEV, AT-PZEV and ZEV hydrogen fuel
cell
automobiles and engines, Honda products have always
demonstrated the
company’s uniquely creative approach to solving engineering
challenges. The S2000 is no different. It is a showcase of Honda
technologies and advanced engineering techniques applied in a
cost-effective manner.

Honda S2000 Features

The following is a list of the standard features found on the
S2000 roadster:

Engineering Features

* 240-hp, 2.2-liter, 16-valve, DOHC VTEC engine
* Multi-Point Programmed Fuel Injection (PGM-FI)
* Direct ignition system
* Low-back pressure exhaust system with high-efficiency
catalyst
* Low-Emission Vehicle-rated (LEV)
* 6-speed, manual transmission
* Torque-sensing limited-slip differential
* Power-assisted 4-wheel disc brakes with ABS
* High-rigidity “high X-bone frame”
* In-wheel double wishbone suspension with gas-filled shock
absorbers and front and rear stabilizer bars
* Electric Power Steering system (EPS)
* Variable-ratio rack-and-pinion steering
* 17-inch alloy wheels (7.0-inch-wide front/8.5-inch-wide
rear)
* 215/45 R17 87W front tires
* 245/40 R17 91W rear tires

Exterior Features

* Electrically powered soft top
* Aluminum hood
* High-intensity discharge (HID) projector headlights
* Body-colored dual power mirrors
* Dual-outlet exhaust with oval tips
* 5-mph, impact-absorbing body-colored bumpers

Interior Features

* Dual airbags (SRS)
* Air conditioning
* Micron air-filtration system
* AM/FM stereo with CD player and XM Satellite Radio
capability
* Remote-operated audio controls
* Power windows
* Power door locks
* Cruise control
* Digital instrument panel
* Leather-trimmed seats
* Center console storage compartments with sliding lid
* Dual Beverage holder
* 3-point seat belts with pretensioner and load limiter
* Engine start button
* Immobilizer Theft-Deterrent System
* Keyless entry system for doors and trunk

Exterior and Interior Colors

* Grand Prix White/Light Tan
* New Formula Red/Black
* Sebring Silver Metallic/ Black or Black and Red
* Silverstone Metallic/Black or Black and Red
* Berlina Black/Black
* Rio Yellow Pearl/Black
* Suzuka Blue Pearl/Blue

http://www.hondanews.com/channels/ho...-2?query=s2000

2004 Honda S2000 - Body

Body

The S2000 is an open-topped, two-seat roadster, designed
for
enthusiast drivers. The S2000 uses steel body construction with
the
exception of the hood, which is aluminum. The S2000 body and
interior
also incorporate class-leading safety, quality and comfort
features.

New for 2004

A freshened exterior appearance gives the 2004 S2000 a
more
powerful appearance through a wider opening air intake for a
pronounced and bold look. The rear exterior has a wider, more
horizontal stance with a lower height. New oval, large diameter,
exhaust tips accent a powerful presence. Larger wheels and
tires
(17-inch) add to the aggressive demeanor of the S2000.
Headlights and
taillights have been reconfigured with triple beam designs
(instead
of dual beam designs) that enhance an already-sophisticated
appearance.

Honda S2000 Body Features

* Electrically powered soft top
* Cockpit air deflector
* Integrated roll bars
* High-intensity discharge (HID) projector-type
headlights
* Lightweight 17-inch alloy wheels
* Body-colored dual power mirrors
* Dual exhaust
* Impact-absorbing, 5-mph, body-colored bumpers

2004 Exterior Changes

The exterior has the following changes for 2004:

* Front bumper design improves aerodynamic performance
and uses
a wide open air intake
* Rear bumper design is lower to the ground and is
accented by
large-diameter dual oval exhaust tips
* Triple Beam projector headlight design replaces dual
beam
headlight reflector headlight design.
* Triple lamp LED taillight design replaces a traditional dual
lamp setup.
* Larger wheels and tires (17-inch) provide a more
aggressive
appearance while adding to overall performance
* Spiral double horn replaces flat double horn

Body
2004 2003 Change
Aerodynamics Enhanced
-
5% improvement in Cd from new front bumper

design
Body Rigidity Enhanced
-
Rigidity increased
Front Bumper Redesigned
-
New bumper and new triple-beam headlight

design
Rear Bumper Redesigned
-
New bumper, triple beam LED taillights and oval

exhaust
tip
Weight (lbs.) 2835 2811 +24, attributable to new wheels and body rigidity increase
Exterior Dimensions

L x W x H (inches) 162.2 × 68.9 × 50.0 162.2 × 68.9 × 50.0 Same

Honda S2000 Exterior Dimensions
Inches Millimeters
Length: -- 162.2 4,120
Width: 68.9 1,750
Height: 50.0 1,270
Wheelbase: 94.5 2,400
Track, Front: 57.9 1,470
Track, Rear: 59.4 1,510
.
Pounds Kilograms
Curb Weight: 2,835 1,290
Weight Distribution (%, Front/Rear) 50/50

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

Circular internal projectors house the low beam (HID),
parking
light and front turn lamp. The high beam is a traditional reflector
design.

The taillight design follows a similar triple beam theme with
large, round multi-LED taillights set in clear-lens housings. LED
lights are used on the stop lamps and parking lamps and side
marker
lamps. The reverse indicators and turn signal indicators are
circular
and use traditional incandescent lighting. The squarish side
marker
lamp uses two LED lights.

A small spoiler lip with an LED stoplight is integrated into the
trailing edge of the trunk lid. Dual, chromed oval exhaust tips
visually dominate the rear view of the car. The outside mirrors
and
door handles are body-colored. 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, twin
5-spoke pattern that calls attention to the S2000’s large brake
discs
and calipers.

The S2000’s trunk volume is 5.0 cubic feet. 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 13.2 gallons.

Convertible Top

The S2000 features a power-operated, soft convertible top
with a
rear glass window. Pushing the switch on the center console
opens or
closes the top in about six seconds, and two manually operated
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. The rear glass window features a
defogger.

Accessory Hardtop

A hardtop for the Honda S2000 is available as a genuine
Honda
Accessory. Constructed of lightweight aluminum, the hardtop
includes
a large glass rear window with a defogger and a simple
attachment
process. The top provides both reduced interior noise and an
aggressive new look. Available in all factory S2000 colors, the
top
uses the same manufacturing and painting processes as used
on the
S2000 factory line to insure the highest quality and factory-look
finish possible. The hardtop weighs 44 lbs. and can be removed
by the
customer.

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 is located
between the driver’s and passenger’s roll bars and acts as a
wind
deflector to help reduce cockpit turbulence.

NVH Features

Measures employed on the S2000 to minimize and control
NVH (noise,
vibration and harshness) include vibration-absorbing engine
mounts
and suspension bushings, resonance-damping chambers in
the intake and
exhaust systems and soundproof materials applied to the floor,
floor
tunnel and trunk.

Exterior Colors

The 2004 S2000 features the following colors:
Exterior Color Interior Trim
Grand Prix White Light Tan
New Formula Red Black
Sebring Silver Metallic Black or Black and Red
Silverstone Metallic Black or Black and Red
Berlina Black Black
Rio Yellow Pearl Black
Suzuka Blue Pearl Blue

http://www.hondanews.com/channels/ho...or?query=s2000

2004 Honda S2000 -- Interior

Interior

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.

New for 2004

The 2004 S2000 benefits from a wide range of interior
enhancements
that make it a better all-around daily driver. Redesigned door
panels
provide more shoulder and elbow room, and a new center
console
provides greater utility and improved audio.

Honda S2000 Interior Features

* Driver-oriented control layout
* Excellent outward visibility
* Dual airbags (SRS)
* Air conditioning
* Micron air-filtration system
* AM/FM stereo CD player with optional XM Satellite
Radio
* Power windows
* Power door locks
* Power mirrors
* Cruise control
* Digital instrument panel
* Leather-trimmed seats
* Center console storage compartments w/lock
* Center console cupholders (2) w/ one touch sliding
lid
* 12-volt power outlet
* 3-point seat belts with pretensioner and load limiter
* Remote-operated audio controls
* Immobilizer Theft-Deterrent System
* Engine start button
* Keyless entry system

2004 Interior Changes

The interior has the following changes for 2004:

* Door panels on both sides are sculpted more deeply


o Elbow room increased by as much as 0.9 inches (20
mm)
o The lower door pocket has more storage space,
o The tweeter housing is reshaped and more integrated
with
the door shape
o Vertical elbow pad is larger
* New interior trim and related pieces include:


o Ignition wave key design features decorative
aluminum-look
panel with S2000 logo
o An aluminum shift knob with genuine leather
o A genuine leather shift boot
o Revised aluminum-look radio lid
o Aluminum-look console lid, head restraint cover
o Cruise control buttons on steering wheel add Cancel
center
button
* Center console redesigned to provide:


o Two cupholders (previously just one)
o A one-touch sliding lid
o A storage tray to place small objects such as coins
* Updated instrument panel meter design


o Digital tachometer features less distance between
segments
o Integrated clock added
o Security indicator lamp added
* New black and red interior color is available with Sebring
Silver Metallic or Silverstone Metallic exterior colors

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 with set, resume and cancel buttons.

The 6-speed shifter, emergency flasher switch, hand brake
lever
and power-operated soft-top switch are housed in the central
console,
along with beverage holders 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.

Audio System

The AM/FM stereo and CD player sits beneath the center of
the
instrument panel, at the forward end of the center console. A
flip-down cover hides the radio controls from view and from the
elements. The 30-watt, four speaker system features two front
mid-range speakers in the lower door panel and two tweeters
mounted
on the upper door.

For 2004, dealer-installed headrest tweeters are available
(two
per seat) and the head unit is XM Satellite Radio-capable with
the
addition of a dealer-installed XM Satellite Radio Receiver and
antenna. The optional satellite antenna has a sleek, low-profile
design and is painted Satin Silver Mist. For a monthly fee, XM
Satellite Radio features over 100 digitally broadcast channels
and
delivers CD-quality sound with text information such as artist,
song
title and album title.

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.

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 100-rpm
increments. The
tachometer flashes red when the engine redline is approached
at 8000
rpm (the fuel cutoff is set at 8200 rpm). 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. For 2004, the
tachometer
features reduced distance between each segment. Plus, a
digital clock
and a security system indicator lamp have been added.

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 center 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

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).

S2000 Safety Systems

The driver’s and passenger’s SRS (Supplemental Restraint
System)
both use a 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. 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 1.5-inch diameter high-strength steel pipe with
a
0.08-inch wall thickness, and tied directly into the frame.
Protection is provided by reinforced door pillars, windshield
posts
and the windshield frame.

The S2000 incorporates pedestrian injury-reducing
technol-ogy in
the form of collapsible hood hinges and windshield-wiper pivots,
designed to help minimize the chances of head injury to a
pedestrian
in a collision.

http://www.hondanews.com/channels/ho...-2?query=s2000

2004 Honda S2000 -- Chassis

Chassis

Overview

A front-engine/rear-wheel-drive configuration is used 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.

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

New for 2004

Objectives for enhancing the 2004 S2000 chassis included
simultaneously improving both at-the-limit track performance
and the
street performance during everyday driving conditions. Honda
engineers re-visited the performance of the tires and
suspension to
improve overall handling of the S2000 and enhance “limit
controllability.” To accomplish this, the tire size was increased,
body rigidity improved, rear suspension bump steer qualities
minimized, and the rear roll center was lowered.

Significant changes include:

* Revised spring, shock absorber and stabilizer bar
rates
* 17-inch wheels and tires (increase from 16-inch)
* Optimized rear toe settings
* Enhanced suspension bushings
* Revised Electrically Powered Steering (EPS) programming
with
optimized steering gearbox ratios and enhanced steering
bushing
rigidity
* Body rigidity increased
* Brake pedal rigidity and build-up feel increased
* Brake pads upgraded to enhance brake fade durability and
master cylinder power ratio optimized

2004 S2000 Suspension Features

The following Honda-designed chassis features contribute
to the
S2000’s exceptional handling and response:

* 50/50(front/rear) weight distribution
* Entire drivetrain located behind the centerline of the front
axle (front mid-engine layout). This helps lower the vehicle’s
center of gravity and helps to centralize vehicle mass, resulting
in a low yaw moment and more responsive vehicle
behavior
* Wide track (57.8 in. front/59.4 in. rear) contributes to
vehicle stability and chassis rigidity
* Highly rigid “high X-bone frame”
* Compact, highly rigid 4-wheel “in-wheel” double wishbone
suspension allows for low hoodline
* Mono-tube shock absorbers
* Electric power steering system
* Four-wheel disc brakes (11.8-in. vented front/11.1-in. solid
rear), with 3- channel ABS
* Limited-slip differential

2004 Honda S2000 vs. 2003 Honda S2000
Suspension
Specifications


Suspension
2004 2003 Change/Notes
Wheels (inches) Front: 17×7.0
Rear: 17×8.5 Front: 16×6.5
Rear: 16×7.5 Front: + 1×0.5 (new wheel design)
Rear: + 1×1 (new wheel design)
Tires Front: P215/45R17
Rear: P245/40R17 Front: P205/55R16
Rear: P225/50R16 +15/10R1
+20/10R1
Springs New Setting
-
Front: Increased spring rate 6.7
Rear: Decreased spring rate 10%
Shock Absorbers New Setting
-
Tuned for new suspension settings
Stabilizer Bars (mm) Front: 26.5x t4.5
Rear: 25.4 x t4.5 Front: 26.5x t4.5
Rear: 27.2 x t4.5 Front: Same
Rear: -1.8
Brake Pads Jurid632(front) NF71 Solid pedal feel and increased resistance to brake fade
Steering Gear Ratio 14.9:1 13.8:1 Tuned to match new tire size

Benefits from Suspension Changes

* Improved cornering grip
* Body torsional rigidity increased for enhanced vehicle
stability
* Greater stability over road disturbances
* Enhanced stability on wet surfaces
* Linear steering feel increased with reprogrammed EPS
system
* Dynamic braking qualities improved

50/50 Weight Distribution

Honda engineers wanted the S2000 to have a balanced
50/50(front-to-rear) weight distribution, considered ideal for a
front-engine rear-wheel-drive roadster. To accomplish this, and
also
lower the center 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 center 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.

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 Rigidity Body and X-Bone 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.

For 2004, S2000 torsional body rigidity has been further
increased
by 10-percent in the front and 9-percent in the back through the
use
of four strategic sets of new reinforcements on the body and
chassis.

* Reinforcements have been added to the rear wheel house
bulkhead
* Reinforcements have been added to the front cross
members
* Brackets have been added to the front upper A-arms
* A performance rod has been added to the front cross
member

Benefits from the increase in body rigidity include decreased
response lag during steering input, improved steering linearity
through enhanced rigidity, and reduced body flex, which can
diminish
handling qualities.

Designing such a strong structure for the initial S2000
posed
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 center 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 lightweight 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.

Since optimum weight distribution and balance are such
important
factors in achieving excellent handling characteristics for 2004
S2000, Honda engineers set the S2000’s engine and drivetrain
as low
and close to the center of the chassis as possible. Suspension
geometry (toe, caster, camber, roll centers, etc.) also have a
tremendous effect on handling and response, so Honda
engineers
designed the double wishbone suspension for the S2000 with
optimum
geometry in mind.

For 2004, modifications have been made to enhance
performance at
the limit, improve control and reduce unwanted sensitivity to
internal and external forces during acceleration and braking.
Overall
suspension geometry has been enhanced by changing the
initial rear
toe and bump steer settings, lowering the roll center, and
optimizing
the shock absorbers, spring rates, stabilizer bar and body
rigidity.

The system boasts many features found on road-racing
suspension
systems, including a compact layout, highly rigid construction,
minimal unsprung weight, a low center 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.

From a handling standpoint, the 2004 S2000 features
improved
steering response and accuracy with a more linear overall feel.
At-the-limit controllability has also been enhanced along with
vehicle stability under heavy accelerator on/off situations.

Wheel Alignment Values:


x 2004 2003
Front:
Toe Angle: 0 0
Camber Angle: - 0 30’ - 0 30’
Caster Angle: 6 6
Rear:
Toe Angle: - 0 10’ - 0 19’
Camber Angle: - 1 30’ - 1 30’

A 1.04×0.18-inch (26.5×4.5mm) front stabilizer bar and a
1.00×0.18-inch (25.4×4.5mm) rear bar contribute to the S2000’s
and
enhanced steering linearity and quality. The bars connect to their
respective suspension arms via ball-jointed links.

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 behavior and improved power transfer characteristics.
They
are also less harsh and better damp body vibration, which gives
the
chassis a more rigid feel. The rear shock absorbers, which
feature
large remote reservoirs, are attached to the lower wishbones,
leaving
more space available for the folding top and space-saver spare
tire.
The 2004 S2000, with the improvement of damping forces,
reduces the
feel of road disturbance while maintaining ride quality.

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.

To achieve higher performance, enhancements have been
made to the
steering system that match the new tire sizes, suspension
settings
and body rigidity specifications. Also, the rigidity of the steering
mount bushings have been increased and the EPS computer
has been
reprogrammed, resulting in a more linear steering 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-brake disc brakes.
Front
rotor diameter is 11.8 inches (300 mm) and the rear diameter is
11.1
inches (282 mm). The front rotors are also vented for added
cooling,
while the rear discs are solid. Brake rotors and calipers are 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 front pad material is Jurid632, a high-performance, low
steel,
fade-resistant type that enhances the brake pedal’s solid feel
and
helps increase resistance to brake fade. Brake-pad area is 42
square
centimeters for the front pads and 27.9 square centimeters for
the
rear-brake pads.

A 7.8-inch, tandem-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.

Anti-Lock Brake System (ABS)

The anti-lock braking system (ABS) is a 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.

The system uses the memory capacity of the system’s
Electronic
Control Unit (ECU) and 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. For the
2004 S2000, with improvement of both hardware and software in
the
compact ABS modulator, memory capacity has increased and
new program
logic has been added which enhances braking efficiency and
reduces
the weight of the system.

Wheels and Tires

Larger wheel and tires for the 2004 S2000 improve overall
grip and
cornering performance. The S2000 features Bridgestone
Potenza RE 050
215/45R 17 87W front tires, mounted on 17 × 7.0 jj
aluminum-alloy
wheels. The rear tires are 245/40R 17 91W and are mounted on
17 × 8.5
jj aluminum-alloy wheels. A space-saver spare tire is in the
trunk.

http://www.hondanews.com/channels/ho...rt?query=s2000



2004 Honda S2000 -- Powertrain Part 1

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-liter, 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
induction 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. The engine’s exhaust emissions qualify the S2000 as a
Low-Emission Vehicle (LEV) in California.

New for 2004

Objectives for enhancing the 2004 S2000 powertrain focus
on
improved power delivery at low and mid-range rpms while
maintaining
the high-revving, race bred nature of the S2000 engine.

Mechanical improvements have been made to many
components of the
engine and transmission to enhance everyday street driving
appeal and
the S2000’s capabilities on the track. More torque is available at
lower rpms while the overall enhanced power band increases
dynamic
transitional capabilities, i.e. exiting corners faster. Significant
changes include:

* 2.2-liter engine displacement (increased from 2.0
liters)
* Horsepower and torque band increased 4- to 10-percent
between
1000 rpm and 8000 rpm with useful high performance power
now
starting at 3000 rpm.
* Transmission gear ratios revised (4% lower on gears one
through four)
* Transmission efficiency and direct feel improved with
carbon
synchronizers

2004 S2000 vs. 2003 S2000

Between 1000 rpm and 8000 rpm, available torque and
horsepower
increase between 4 and 10 percent. Additionally, useful power
for
high performance acceleration begins at about 3000 rpm
compared to
about 6000 rpm on the 2000 – 2003 models. The performance
improvement
at lower rpm ranges can be attributed to the increase in
displacement
and revised valvetrain tuning. Lower gear ratios on gears one
through
four further magnify the new performance characteristics of the
engine.

The enhanced powerband benefits acceleration response at
lower
rpms and improves the overall “powerful feel” of the car in
everyday
driving. To increase the engine displacement, powerband, and
direct
transmission feel of the vehicle, the following specifications and
components have changed:
2004 2003 Change/Notes
Engine
Engine 2.2-liter DOHC VTEC 2.0-liter DOHC VTEC + 0.2 liters, attributable to engine stroke change
Horsepower 240 @ 7800 rpm 240 @ 8300 rpm + 0 hp @ -500 rpm, same peak horsepower with overall powerband characteristics strengthened by 4% to 10%

between
1000 and 8000 rpm
Torque (lbs.-ft.) 162 @ 6500 rpm 153 @ 7500 rpm +9 lb.-ft. @ -1000 rpm with improved powerband characteristics strengthened by 4% – 10% between 1000

and
8000 rpm. Max torque increases 5%.
Rev Limit / Fuel Cutoff) 8000/8200 8800/9000 Piston travel configuration decreases rpm limit by 9% because of piston speed increase.
Compression Ratio 11.1:1 11.0:1 +0.1:1
Bore x Stroke (mm) 87.0×90.7 87.0x 84.0 0.0x+6.7
Crankshaft Half Stroke (mm) 45.3 42.0 +3.3 (Crankshaft determines stroke length and creates displacement change)
Connecting Rod Length (mm) 149.65 153.0 -3.35 (Calibrated for crankshaft half stroke)
VTEC (low-speed profile) Reconfigured
-
Low-speed intake duration decreased and exhaust

duration
increased for more torque
VTEC (high-speed profile) Reconfigured
-
High-speed intake and exhaust duration slightly

decreased
for torque and top horsepower
Transmission
Transmission Ratios Reconfigured
-
Gears 1-4 = 4% lower for performance
Gear 5 = 1% lower
Gear 6 = 2% higher
Synchronizers Carbon (Double carbon single cone on 1-2 and single carbon cone on 3-6) Brass (Triple Cone or double cone on gears 1-4) Carbon material reduces mechanical loss and

increases
capacity of synchronizer

2004 Powertrain Main Features

The following are the main features of the S2000
powertrain:

2.2-Liter (2178 cc) VTEC Engine

* 8000rpm rev limit
* 240 hp @ 7800 rpm
* 162 lb.-ft. of torque @ 6500 rpm
* 0-60 mph acceleration in less than 6 seconds
* Compact, lightweight engine design aids in ideal (50/50)
weight distribution
* FRM (Fiber-Reinforced Metal) cylinder liners
* 87.0 mm bore X 90.7 mm stroke contributes to increased
torque
band
* Rigid aluminum (ladder-type) main bearing support, with
cast-iron bearing inserts, enhances engine durability
* Lightweight forged-aluminum pistons and heat-treated
(carburized), forged-steel connecting rods add durability
* Full-floating piston pins eliminate piston noise during
warm-up
* High-volume oil pump with silent chain drive
* Compact, high-efficiency oil cooler
* Cast-aluminum oil pan helps minimize engine noise and
enhances
oil cooling
* 11.1:1 compression ratio
* Compact, DOHC VTEC cylinder head and valvetrain
* Lightweight, MIM (Metal-Injection Molded), sintered-steel
rocker arms
* Low-friction roller-bearing cam-followers
* Compact, 2-stage cam-drive with silent chain, scissors
gears
and fully automatic tensioner
* Hollow camshafts function as lubrication path for VTEC
valvetrain
* Sequential, Multi-Point Programmed Fuel Injection
(PGM-FI)
* Intake system with straight inlet ports and low-back
pressure
exhaust system
* Electric-motor-driven, multi-port secondary air-assist
injection system helps lower hydrocarbon emissions
* Meets California’s stringent Low-Emission Vehicle (LEV)
standard
* Compact engine ancillary drive system uses a serpentine
drive
belt with automatic tensioner
* Compact engine ancillaries, such as air-conditioning
compressor and water pump, save weight and take up less
space
* Direct-ignition system with long-lasting platinum-tipped
spark
plugs
* Low back pressure, metal-honeycomb catalytic
converter

Transmission

* Longitudinally mounted 6-speed manual
transmission
* Transmission lubrication pump enhances durability
* Reduced shift effort and direct feel from carbon
synchronizers
on gears one through six
* Short-throw, direct shift linkage
* Compact pull-type clutch mechanism and
high-performance
clutch
* Propeller shaft uses highly durable constant-velocity
joints
* Torsen limited-slip differential
* Highly rigid axle shafts utilize stronger flanged ends in
place of splines

http://www.hondanews.com/channels/ho...-2?query=s2000



2004 Honda S2000 -- Powertrain Part 2

S2000 Engine Design

Honda engineers designed the S2000 to achieve an ideal
50/50
weight distribution, a low yaw moment and a low center 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. The
engine
code designation is F22C1.

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.
Additionally, “dummy head honing,” a process where the engine
block
cylinders are honed with a “dummy” cylinder head tightened to
the
block, improves machining accuracy for stability of piston
movement.

For 2004, cylinder bore is 3.42 in. (87.0 mm) and the stroke
is
3.57 in. (90.7 mm). This results in a slightly “over square” 1: 1.04
bore-stroke ratio that facilitates good torque characteristics at
lower rpm while delivering high-rpm performance.

For comparison, the 2000-2003 model’s cylinder bore is
3.42 in.
(87.0 mm) and the stroke is 3.30 in. (84.0 mm) that results in a
nearly “square” 1: 0.96 bore-stroke ratio.

Forged-Aluminum Pistons

The high-revving nature of the S2000 engine necessitated
the use
of special high-strength, lightweight forged-aluminum pistons).
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.

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 new, 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

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 a
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
smooth and
quiet 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 DOHC VTEC system is a 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 precise metal-injection molding process is used to obtain
the
higher degree of rocker-arm finish required by the roller-type,
coaxial VTEC design. These innovations reduce valvetrain
friction by
approximately 70 percent. 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.

The two overhead camshafts are hollow in order to supply oil
to
the valvetrain with 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. Space efficiency occurs 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 use a powdered-metal injection-molding
process to
make the S2000 engine’s VTEC cam followers. In this 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 produced by metal injection
molding.

Externally Mounted Oil Pump

To help minimize engine length, Honda engineers placed
the oil
pump at the bottom of the engine block instead of its usual
location
at the front of the crankshaft. This placement provides engine
compactness, and the pump scavenges oil more efficiently.
Additionally, the oil pump’s low placement helps pressurize the
lubrication system more quickly during engine startup.

The oil pump itself also is a 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 locate
them at
the side of the engine block (a practice commonly used on
racing
engines) and designed a compact drive system that uses both
sides of
a serpentine belt. An automatic tensioner is built into the drive
system.

Direct-Ignition System

Instead 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 long 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

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 place 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-liter
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 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 backpressure.

Metallic Honeycomb Catalyst

The S2000 exhaust system uses a thin-walled, low-heat
radiating
metal honeycomb catalytic converter in place of the more
traditional
ceramic unit.. The catalyst’s low backpressure also contributes
to
better engine performance.

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.

6-Speed Manual Transmission Overview

The 2004 S2000 has a 6-speed manual transmission. 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.

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. 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 carbon synchronizers for all forward gears helps reduce
shift
effort. Reverse gear uses single-cone brass synchronizer for
smoother
shifting and quieter operation.

Transmission Gear Ratios
Gear 2004 2003 Net Change*
1st 3.133 3.133 4% lower
2nd 2.045 2.045 4% lower
3rd 1.481 1.481 4% lower
4th 1.161 1.161 4% lower
5th 0.943 0.970 1% lower
6th 0.763 0.810 2% higher
Reverse 2.800 2.800 No change
Secondary Gear Reduction 1.208 1.160 4% lower
Final Drive 4.100 4.100 No change
*Net gear ratio change occurs through modification of

the
secondary gear reduction ratio inside the
transmission.

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 wrapped in genuine leather
and
floats in a rubber mounting that absorbs vibration. Reverse-gear
lockout is a mechanical type, which can be released by pushing
the
shift lever downward.

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. The pump provides positive and reliable lubrication, regardless
of G-loading, and helps to prolong gear and synchronizer life.

Compact Heavy-Duty, Pull-Type Clutch

The 2004 S2000 employs 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

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.