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.
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 | |
| First Gear: | 3.133 |
| Second Gear: | 2.045 |
| Third Gear: | 1.481 |
| Fourth Gear: | 1.161 |
| Fifth Gear: | 0.970 |
| Sixth Gear: | 0.810 |
| Reverse Gear: | 2.800 |
| Primary Gear Reduction: | 1.160 |
| Final Drive: | 4.100 |
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 (20% lighter than the Accord engine's
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, which can turn up to 9000 rpm, 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.