INDUCTION SYSTEM

The TSX's induction system has been reworked to increase airflow volume by nine percent and to create a more aggressive, linear engine sound. The revised inlet design allows cool ambient air to be picked up at the front of the vehicle, and then routed though a high-flow filter assembly. The single-stage lightweight plastic intake manifold has fixed-length intake runners that are tuned in length, diameter and shape to provide an optimal blend of low-rpm torque and high-rpm response. The new manifold incorporates new 48 mm intake runner (up 6 mm from the previous design runners) along with a new throttle-body with a 4 mm larger inlet opening.

EXHAUST SYSTEM

To help boost engine torque, the TSX has a new high-flow, low back-pressure exhaust system that contributes to a 15-percent increase in exhaust flow over the previous TSX. Large-diameter pipe sizes throughout the exhaust system increase flow; beyond the under-floor catalytic converter, the exhaust system passes through a pre-chamber under the second-row floor, and then splits just behind the rear axle to feed into free-flowing dual silencers and chrome exhaust tips.

DRIVE-BY-WIRE™ THROTTLE SYSTEM

In place of a conventional mechanical throttle linkage, the TSX uses a Drive-by-Wire™ Throttle System. A DC motor controls the throttle butterfly position in the intake tract. This allows the ratio between pedal movement and throttle motion to be altered to suit the driving conditions. The system monitors throttle pedal position, throttle butterfly position, road speed, engine speed and engine vacuum. This information is used to define the throttle control sensitivity. The system also alters response based on the calculated road slope, providing more throttle gain uphill, and less downhill, and also reduces changes in gain on curvy roads to make the car easier to control.

The drive-by-wire throttle system works with the Sequential SportShift 5-speed automatic transmission to make shifts smooth and quick. With coordination of the throttle opening and the transmission's shifting functions, shift shock and delay are reduced.

EMISSIONS CONTROL

In addition to the TSX engine gaining torque, the 2.4-liter engine has lower emissions. The 2009 TSX is compliant with California Air Resources Board (CARB) LEV II ULEV standard, which is one of the toughest emissions regulations in the United States. TSX also achieves EPA TIER 2 - BIN 5 regulations emissions compliance.

The in-line 4-cylinder engine is designed with emissions performance in mind, employing VTC and a unique i-VTEC® cylinder head promoting internal exhaust gas recirculation, which helps reduce NOx output. Newly designed fuel injectors likewise help reduce hydrocarbons after starting, while a Linear Air/Fuel sensor positioned in the exhaust system just upstream of the catalyst improves air/fuel mixture control.

The exhaust manifold is integrated into the cylinder-head casting in the rear of the transversely mounted engine. This allows the catalytic converter to be positioned very close to the cylinders for swift light-off after a cold engine start. A secondary catalytic converter is positioned under the passenger compartment floor, shortly downstream.

NOISE, VIBRATION & HARSHNESS (NVH) CONTROL

The TSX engine has an array of features designed to reduce noise, vibration and harshness (NVH). The pressure-cast cylinder block has a bed-plate type main bearing cap that results in a highly rigid assembly, which helps to resist vibration. Two balance shafts further smooth the inherent vibration commonly found with a large-displacement in-line 4-cylinder engine layout, and a self-adjusting silent-type camshaft chain and serpentine accessory drive belt also reduce NVH.

100,000 MILE TUNE-UP INTERVAL

Features like a self-adjusting silent-type camshaft chain, long wearing platinum-tipped spark plugs and a precision-engineered valvetrain, all contribute to the TSX's low maintenance needs. Aside from routine fluid changes and inspections, the first scheduled engine tune-up is not required for 100,000 miles or more (may vary with driving conditions).

MAINTENANCE MINDER™ SYSTEM

A standard Maintenance Minder™ system automatically monitors the vehicle's operating condition. The driver is alerted via a message on the Multi-Information Display (MID) when maintenance is required. The system helps eliminate unnecessary service stops, while ensuring that the vehicle is properly maintained.

The Maintenance Minder™ system monitors operating conditions such as coolant and oil temperatures along with engine speed, and then determines the proper service intervals. Depending on the engine operating conditions, oil change intervals can be extended to a maximum of 10,000 miles, potentially sparing the owner considerable money and inconvenience over the life of the vehicle. The system can be reset manually by the owner, and monitors all normal service parts and systems, including oil and filter, air-cleaner, tire rotation, automatic transmission fluid, coolant, spark plugs, timing belt, brake pads and more. Maintenance alerts are presented on the instrument cluster when the ignition is first turned on, and not while driving.

ELECTRONIC CONTROL MOUNT (ECM)

The Electronic Control Mount System is used to minimize the effects of engine vibration. At low engine speed, a vacuum-controlled front engine mount allows additional engine movement, so that less low-frequency vibration is transmitted to the body. At higher rpm, the mount stiffens so that the mass of the engine is properly restrained for better handling.

6-SPEED MANUAL TRANSMISSION

A close-ratio 6-speed manual gearbox is one of two standard transmissions in the TSX. With precise and light shifting action, the manual transmission is designed to compliment the TSX's sporting side. Compared to a 5-speed transmission, the 6-speed gearbox allows for closer ratio staging. This enables the engine to operate closer to its power peak during acceleration for better performance.

A high (numerically low) top gear ratio allows for a relaxed cruising rpm and fuel efficiency. For 2009, the TSX 6-speed manual gearbox has new ratios for second through sixth gears for better performance with the revised engine.

The compact, highly rigid transmission case is cast of magnesium alloy to reduce weight by about seven pounds relative to a comparable aluminum unit. Additionally, the highly rigid casting helps damp out noise and vibration. Multi-cone synchronizers on first through fourth gears reduce and smooth shifting effort.

The low-effort clutch pedal design has a broad engagement band for progressive engagement and smoother launches.

SEQUENTIAL SPORTSHIFT 5-SPEED AUTOMATIC TRANSMISSION WITH PADDLE SHIFTERS

The TSX has a standard Sequential SportShift 5-speed automatic transmission with F1®-style paddle shifters and Grade Logic Control to maximize acceleration, fuel economy and driver control.

Automatic mode
A console mounted, 5-position shift gate makes operation of the transmission simple. When in this mode the transmission operates automatically in the "D" position, selecting among the five forward gear ratios based on the driving conditions. When in automatic mode, the transmission incorporates an advanced Grade Logic Control and Shift Hold Control, both of which work to reduce gear "hunting" on hills and through turns.

Grade Logic Control reduces shift frequency and improves vehicle speed control by altering the transmission's shift schedule when traveling uphill or downhill. The transmission computer continuously compares throttle position, vehicle speed and acceleration/deceleration with a map stored in the computer memory. The Grade Logic Control System determines when the TSX is on an upslope or down slope. The shift schedule is then adjusted to automatically hold the transmission in a lower gear for better climbing power or increased downhill engine braking.

When the throttle is quickly released and the brakes are applied, as might be the case when decelerating for a corner, Shift Hold Control keeps the transmission in its current (lower) ratio. This helps provide added engine braking, and ensures that abundant power is immediately available at the corner exit.

Manual mode
New for 2009, TSX is equipped with steering-wheel mounted paddle shifters. The steering-wheel mounted Sequential SportShift F1®-style paddle shifters are activated when a fingertip pull of the right paddle commands an upshift or a pull of the left paddle commands a downshift. A digital display in the tachometer face indicates which gear the transmission is in when the steering wheel paddles are active.

The steering wheel paddles can operate in both the "D" and "S" transmission positions. When in "D," a touch of a paddle shifter temporarily places the transmission in manual mode (but without gear holding at redline). After comparatively steady-state cruising conditions are detected, the transmission returns to full automatic operation. In "S," engaging a paddle enables gear holding, which allows only driver-commanded shifts, with the exception of automatically shifting to first gear at a stop, even if not driver-selected.

When first placed in "S" mode, the transmission will automatically shift between first, second, third and fourth gears until a paddle shifter is activated. When a paddle shifter is activated, the transmission goes into full manual mode.

Manual mode protective features
An array of protective features is active when the transmission is in manual mode to help protect the engine and drivetrain from damage. The Powertrain Control Module (PCM) will cut off fuel flow to the engine if there is a possibility of over-revving in a gear, as might occur if the driver is late in commanding an upshift. To prevent over-revving while downshifting, the transmission will not execute a driver-commanded downshift that would send the engine beyond redline in the lower gear. Even if the driver allows the vehicle to come to a stop in a high gear, the transmission will automatically downshift to first gear to prevent lugging away from a stop in a high gear.

COOPERATION BETWEEN 5-SPEED AUTOMATIC TRANSMISSION & DRIVE-BY-WIRE™ THROTTLE SYSTEM

With the TSX's electronically controlled automatic transmission and Drive-by-Wire™ Throttle System, the function of the engine and transmission are closely choreographed for faster, smoother shifting. As a result, shift shock is reduced significantly during upshifts and downshifts.

ACTIVE LOCKUP TORQUE CONVERTER

To provide good fuel economy while maintaining a high level of drivability, the 5-speed automatic transmission includes an active lockup torque converter. With the precise control afforded by a linear solenoid and assist spring, the system features a wide range of speed and throttle settings in which lockup can be engaged in the top four gears. This results in excellent fuel economy in both city and highway driving.

LOW-FRICTION CLUTCH DISC FOR AUTOMATIC TRANSMISSION

To provide better fuel efficiency, a special low-friction clutch disc is used for all five gears.