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)
  
 
87.0x90.7
  
 
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