Using the most high-strength steel in the model's history, the 2013 Honda Accord Sedan and Coupe bodies combine sophisticated and athletic styling with remarkable aerodynamic streamlining. Revised Advanced Compatibility Engineering™ (ACE™) body structures improve frontal crash safety, making the all-new Accord one of few midsize offerings expected to excel in the upcoming small-overlap frontal barrier crash test.
Along with the increased horsepower, the updated V-6 also contributes to a 13-percent increase in the estimated EPA highway fuel economy rating (with automatic transmission), thanks in part to internal friction reduction features including an oil-ring ion-plating treatment, plateau honing and reduced auxiliary-belt tension. A new tumble-type intake port design improves combustion efficiency, and torque-converter function in the new available 6-speed automatic transmission has been refined. A 3.5-percent weight reduction is due to a new cylinder head bridge structure with separate rocker arm holders and lightweight resin cam covers. The Accord V-6 has an estimated EPA fuel economy rating of 21/34/251 mpg city/hwy/combined (Sedan 6AT).
A new cooling control spacer positioned in the water jacket surrounding the cylinders helps to keep operating temperature and tolerances more consistent. Plateau honing further lowers the friction level between the pistons and the cylinders by creating an ultra-smooth surface. This 2-stage machining process uses two grinding processes instead of the more conventional single honing process. Plateau honing also enhances the long-term wear characteristics of the engine.
The "intelligent" portion of the system is its ability to vary valve operation based on the driving situation and engine rpm. At low rpm, the VTEC intake valve timing and lift are optimized for increased torque, which now allows a wider range of 3-cylinder operation (when equipped with automatic transmission). As engine rpm builds past 5150 rpm (6AT; 6MT: 4900 rpm) the VTEC system transitions to a high-lift, long-duration intake cam profile for superior high-rpm engine power. In cylinder cut-off mode (6AT models), the rear bank of intake and exhaust valves remain closed, to eliminate pumping losses.
During startup, aggressive acceleration or when climbing hills – any time high power output is required – the engine operates on all six cylinders. During moderate-speed cruising and at low or moderate engine loads, the system operates just the front bank of three cylinders.
The VCM system can tailor the working displacement of the engine to match the driving requirements from moment to moment. Since the system automatically closes both the intake and exhaust valves of the cylinders that are not used, pumping losses associated with intake and exhaust are eliminated and fuel efficiency gets a further boost. The system combines maximum performance and maximum fuel efficiency – two characteristics that don't typically coexist in conventional engines.
VCM deactivates specific cylinders by using the VTEC (Variable Valve-Timing and Lift Electronic Control) system to close the intake and exhaust valves while simultaneously the Powertrain Control Module cuts fuel to those cylinders. The spark plugs continue to fire in inactive cylinders to minimize plug temperature loss and prevent fouling induced from incomplete combustion during cylinder re-activation.
The system is electronically controlled, and uses special integrated spool valves in the cylinder heads. Based on commands from the system's electronic control unit, the spool valves selectively direct oil pressure to the rocker arms for specific cylinders. This oil pressure in turn drives synchronizing pistons that connect and disconnect the rocker arms.
The VCM system monitors throttle position, vehicle speed, engine speed, automatic-transmission gear selection and other factors to determine the correct cylinder activation scheme for the operating conditions. In addition, the system determines whether engine oil pressure is suitable for VCM switching and whether catalytic-converter temperature will remain in the proper range. To smooth the torque-induced jolt of activating or deactivating cylinders, the system adjusts ignition timing, drive-by-wire throttle position and turns the torque converter lock-up on and off. As a result, the transition between 3- and 6-cylinder operation is unnoticeable to the driver.
- See more at: http://www.seriouswheels.com/cars/2013/top-2013-Honda-Accord-EX-L-V-6-Coupe.html#sthash.mXXuoY6h.dpuf
Body
Crisply styled and aerodynamically efficient, the 2013 Accord Sedan and Coupe body designs are the most sophisticated in Accord history. The 2013 Accord unit-body uses 55.8-percent high-tensile steel, more than in any previous Accord. In addition, 17.2-percent of the steel is now grade 780, 980 and 1,500 – extremely high grades that have never before been used in any Accord. This contributes to higher body rigidity and reduced weight, which directly benefits ride and handling, interior quietness, performance and efficiency and long-term durability.3.5-liter SOHC i-VTEC V-6
The Earth Dreams™ 3.5-liter V-6 engine available in the Accord EX-L V-6 and Touring Sedan, and EX-L V-6 Coupe has been extensively reworked for 2013 with a range of improvements including revised intake and exhaust ports, updated valve timing and Variable Valve Timing and Lift Electronic Control (VTEC), and when equipped with automatic transmission, Variable Cylinder Management (VCM) with a wider range of operation. The aluminum-alloy 24-valve engine now produces 278 horsepower at 6200 rpm (an increase of seven horsepower) and generates 252 lb-ft of torque at 4900 rpm. Torque is markedly improved in the lower ranges below 4900 rpm where the engine typically operates.Along with the increased horsepower, the updated V-6 also contributes to a 13-percent increase in the estimated EPA highway fuel economy rating (with automatic transmission), thanks in part to internal friction reduction features including an oil-ring ion-plating treatment, plateau honing and reduced auxiliary-belt tension. A new tumble-type intake port design improves combustion efficiency, and torque-converter function in the new available 6-speed automatic transmission has been refined. A 3.5-percent weight reduction is due to a new cylinder head bridge structure with separate rocker arm holders and lightweight resin cam covers. The Accord V-6 has an estimated EPA fuel economy rating of 21/34/251 mpg city/hwy/combined (Sedan 6AT).
Engine Block and Crankshaft
With its 60-degree V-angle, the Accord's V-6 engine is inherently smooth and has compact overall dimensions that allow efficient packaging within the vehicle. The V-6 has a die-cast lightweight aluminum alloy block with cast-in-place iron cylinder liners. Made with a centrifugal spin-casting process, the thin-wall liners are high in strength and low in porosity. The block incorporates a deep-skirt design with four bolts per bearing cap for rigid crankshaft support and minimized noise and vibration.A new cooling control spacer positioned in the water jacket surrounding the cylinders helps to keep operating temperature and tolerances more consistent. Plateau honing further lowers the friction level between the pistons and the cylinders by creating an ultra-smooth surface. This 2-stage machining process uses two grinding processes instead of the more conventional single honing process. Plateau honing also enhances the long-term wear characteristics of the engine.
Cylinder Heads/Valvetrain
Like other Honda V-6 powerplants, the new 2013 Accord V-6 engine's 4-valve cylinder heads are a single-overhead-camshaft design, with the cams driven by the crankshaft via an automatically tensioned toothed belt. Made of low-pressure cast, low-porosity aluminum, each cylinder head incorporates a new "tumble port" design that improves combustion efficiency. An integrated exhaust manifold cast into each cylinder head reduces parts count, improves flow and optimizes the location of the close-coupled catalyst.i-VTEC with 2-stage Variable Cylinder Management™ (VCM™)
The Accord's available SOHC V-6 with automatic transmission includes a new generation of i-VTEC with Variable Cylinder Management (VCM). Advances to VCM technology make a large contribution to the Accord V-6's estimated EPA fuel economy rating of 21/34/25 mpg city/hwy/combined (Sedan with automatic transmission). That's an increase over the EPA rating for the previous Accord V-6 (20/30/24 mpg city/hwy/combined) of 1-mpg city, 4-mpg hwy and 1-mpg combined.i-VTEC Valve Control System
The Accord's V-6 engine combines Variable Cylinder Management (VCM) (when equipped with automatic transmission) with Variable Valve Timing and Lift Electronic Control (VTEC), which changes valve lift, timing and duration of the intake valves. A new switching mechanism allows each cylinder to operate with low-rpm valve lift and duration or high rpm lift and duration. When equipped with automatic transmission, the rear cylinder bank can also leave all intake and exhaust valves closed to maximize fuel efficiency during cylinder deactivation.The "intelligent" portion of the system is its ability to vary valve operation based on the driving situation and engine rpm. At low rpm, the VTEC intake valve timing and lift are optimized for increased torque, which now allows a wider range of 3-cylinder operation (when equipped with automatic transmission). As engine rpm builds past 5150 rpm (6AT; 6MT: 4900 rpm) the VTEC system transitions to a high-lift, long-duration intake cam profile for superior high-rpm engine power. In cylinder cut-off mode (6AT models), the rear bank of intake and exhaust valves remain closed, to eliminate pumping losses.
VCM Operation
To help improve the fuel efficiency of the V-6 engine, a new generation of Honda's Variable Cylinder Management (VCM) is used in models with automatic transmission. In 2008 through 2012 Accord V-6 models, Variable Cylinder Management (VCM) operated on three cylinders for cruising, four cylinders for modest acceleration or six cylinders for strong acceleration. Advancements to the VTEC system and active engine mounts now allow the VCM system to operate with three cylinders in a wider range of situations to maximize fuel efficiency and lower emissions. Four-cylinder operation has been eliminated for 2013. When greater power is needed, the system switches seamlessly to 6-cylinder operation.During startup, aggressive acceleration or when climbing hills – any time high power output is required – the engine operates on all six cylinders. During moderate-speed cruising and at low or moderate engine loads, the system operates just the front bank of three cylinders.
The VCM system can tailor the working displacement of the engine to match the driving requirements from moment to moment. Since the system automatically closes both the intake and exhaust valves of the cylinders that are not used, pumping losses associated with intake and exhaust are eliminated and fuel efficiency gets a further boost. The system combines maximum performance and maximum fuel efficiency – two characteristics that don't typically coexist in conventional engines.
VCM deactivates specific cylinders by using the VTEC (Variable Valve-Timing and Lift Electronic Control) system to close the intake and exhaust valves while simultaneously the Powertrain Control Module cuts fuel to those cylinders. The spark plugs continue to fire in inactive cylinders to minimize plug temperature loss and prevent fouling induced from incomplete combustion during cylinder re-activation.
The system is electronically controlled, and uses special integrated spool valves in the cylinder heads. Based on commands from the system's electronic control unit, the spool valves selectively direct oil pressure to the rocker arms for specific cylinders. This oil pressure in turn drives synchronizing pistons that connect and disconnect the rocker arms.
The VCM system monitors throttle position, vehicle speed, engine speed, automatic-transmission gear selection and other factors to determine the correct cylinder activation scheme for the operating conditions. In addition, the system determines whether engine oil pressure is suitable for VCM switching and whether catalytic-converter temperature will remain in the proper range. To smooth the torque-induced jolt of activating or deactivating cylinders, the system adjusts ignition timing, drive-by-wire throttle position and turns the torque converter lock-up on and off. As a result, the transition between 3- and 6-cylinder operation is unnoticeable to the driver.
Active Control Engine Mounts and Active Noise Control
A new-generation 28-volt Active Control Engine Mount system (ACM) is used to minimize the effects of engine vibration as the VCM system switches cylinders on and off. The more powerful 28-volt ACM is a key factor in the VCM's broader range of operation in the new Accord. Sensors alert the Electronic Control Unit (ECU) to direct ACM actuators positioned at the front and rear of the engine to move to cancel engine vibration. Inside the interior of the Accord, an Active Noise Control system (ANC) works in cooperation with the ACM system to further reduce any sound relating to the function of the VCM system. (See Interior tab for more information.)Programmed Fuel Injection (PGM-FI)
The V-6 engine's Programmed Fuel Injection (PGM-FI) continually adjusts fuel delivery to yield the best combination of power, low fuel consumption and low emissions. Multiple sensors constantly monitor critical operating parameters, such as throttle position, intake air temperature, coolant temperature, ambient air pressure, intake airflow volume, intake manifold pressure, exhaust air-fuel ratio and the position of the crankshaft and cams.- See more at: http://www.seriouswheels.com/cars/2013/top-2013-Honda-Accord-EX-L-V-6-Coupe.html#sthash.mXXuoY6h.dpuf
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