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91-513: I-VTEC is the acronym for intelligent VTEC (Variable Valve Timing and Lift Electronic Control), an evolution of Honda's VTEC engine. The i-VTEC engine works by controlling the timing and lifting of the camshafts depending on engine speeds. The valves open a small amount during low engine speeds to achieve optimal fuel efficiency . The valves will open wider at higher engine speeds to achieve higher performance. Honda i-VTEC (intelligent-VTEC) has VTC continuously variable timing of camshaft phasing on

182-411: A Bundorf analysis . Great care must be taken to avoid conflating the understeer/oversteer behavior with the limit behavior of a vehicle. The physics are very different. They have different handling implications and different causes. The former is concerned with tire distortion effects due to slip and camber angles as increasing levels of lateral acceleration are attained. The latter is concerned with

273-444: A solenoid is actuated that allows oil pressure from a spool valve to operate a locking pin, which binds the high-RPM rocker arm to the low-RPM ones. From this point on, the valves open and close according to the high-lift profile, which opens the valve further and for a longer time. The switch-over point is variable, between a minimum and maximum point, and is determined by engine load. The switch-down back from high- to low-RPM cams

364-527: A 150 bhp (110 kW) B16A1 variant. The United States market saw its first VTEC system with the introduction of the 1991 Acura NSX , which used a 3-litre DOHC C30A V6 with 270 bhp (200 kW). DOHC VTEC engines soon appeared in other vehicles, such as the 1992 Acura Integra GS-R (160 bhp (120 kW) B17A1 ), and later in the 1993 Honda Prelude VTEC (195 bhp (145 kW) H22A ) and Honda Del Sol VTEC (160 bhp (120 kW) B16A3 ). The Integra Type R (1995–2000) available in

455-412: A cart, walk with a person while holding hands, perform the tasks of a receptionist, carry out delivery service and be an information guide. In addition to enhanced visual sensors, floor surface sensors and ultrasonic sensors, Honda developed an IC Teleinteraction Communication Card which allows ASIMO to recognize the location and identity of the person who is standing within a 360-degree range. The IC card

546-507: A common camshaft for both intake and exhaust valves. The trade-off was that Honda's SOHC engines benefited from the VTEC mechanism only on the intake valves. This is because VTEC requires a third center rocker arm and cam lobe (for each intake and exhaust side), and, in the SOHC engine, the spark plugs are situated between the two exhaust rocker arms, leaving no room for the VTEC rocker arm. Additionally,

637-400: A high-torque performance. When the gasoline engine enters a higher rpm range, the electric motor ceases and power output is supplied by the VTEC engine. The assistance from the electric motor reduces the work of the gasoline engine, allowing the engine to be downscaled. This results in better mileage and reduces fuel consumption. The power from the electric motor is generated and conserved when

728-464: A majority of the time, occur in trade for a power and efficiency loss at higher-RPM ranges. Correspondingly, VTEC attempts to combine low-RPM fuel efficiency and stability with high-RPM performance. VTEC, the original Honda variable valve control system, originated from REV (Revolution-Modulated Valve Control) introduced on the CBR400 in 1983 known as HYPER VTEC. In the regular four-stroke automobile engine,

819-489: A newly developed information-extraction technology to link the analysis and command ASIMO to move. An electronic helmet is developed to allow humans to control the robot just by thinking about making the movement. This was demonstrated by scientists at the Honda Research Institute, who showed that it took only a few seconds for thought to be translated into robotic action. The technology is still under development and

910-729: A normal engine operating mode and improves the mid-range power curve. At 5500-7000 RPM, the second VTEC solenoid engages (both solenoids now engaged) so that both intake valves are using a middle, third camshaft lobe. The third lobe is tuned for high-performance and provides peak power at the top end of the RPM range. In newer version of 3-Stage i-VTEC combined VTC and PGM-FI to allow ECU to control full range of mode to archive greater fuel economy improvements and performance. Honda CR-Z able to switch between low-end mode and standard mode from 1000 rpm to 2250 rpm uninterrupted and engage to high cam mode from 2250 rpm upward on SOHC. Honda i-VTEC (intelligent-VTEC)

1001-478: A research and development program undertaken by Honda's associates to challenge the field of mobility. The advancement of the research prompted Honda to conceive a humanoid robot capable of interacting with humans and is able to function in society, such as supporting the disabled and elderly. ASIMO started as a pair of mechanical legs and had been in development for over 20 years. E0, the first prototype, debuted in 1986 and evolved into prototype E7 in 1991. By 1993,

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1092-521: A steering angle sensor to monitor the driver's steering direction, the yaw sensor to detect the momentum of which the wheels are steering (yaw rate), and a lateral acceleration (g-force) sensor to signal the changes in speed. At the same time, the TCS will prevent wheel slip during acceleration while the side-slip control stabilizes cornering when the rear or front wheels slip sideways (during oversteer and understeer). Controlling oversteer  - During oversteer,

1183-531: A unit. The same occurs for the intake rocker shaft, except that the high-profile camshaft lobe operates the primary rocker arm. The J37A2 is able to use both intake and exhaust VTEC by use of a novel design of the intake rocker arm. Each exhaust valve on the J37A2 corresponds to one primary and one secondary exhaust rocker arm. Therefore, there are a total of twelve primary exhaust rocker arms and twelve secondary exhaust rocker arms. However, each secondary intake rocker arm

1274-408: A very mild cam lobe with little lift and a normal cam lobe with moderate lift. Because of this, at low RPM, when VTEC is not engaged, one of the two intake valves is allowed to open only a very small amount due to the mild cam lobe, forcing most of the intake charge through the other open intake valve with the normal cam lobe. This induces swirl of the intake charge which improves air/fuel atomization in

1365-588: Is a system that combines VTEC with Honda's VTC (Variable Timing Control), a continuously variable camshaft phasing system used on the intake camshaft of DOHC VTEC engines. The technology first appeared on Honda's K-series four-cylinder engine family in 2001. Most Honda or Acura four-cylinder powered vehicles sold in the United States used i-VTEC by the 2002 model year with the exception being the 2002 Honda Accord. VTEC controls of valve lift and valve duration are still limited to distinct low- and high-RPM profiles, but

1456-543: Is able to run on 3, 4, or all 6 cylinders based on the power requirement, essentially getting the best of both worlds. V6 power when accelerating or climbing, as well as the efficiency of a smaller engine when cruising. The technology was originally introduced to the US on the 2005 Honda Odyssey minivan, and can now be found on the Honda Accord Hybrid, the 2006 Honda Pilot, and the 2008 Honda Accord. Example: EPA estimates for

1547-668: Is also capable of choosing its movement when approaching people, whether stepping back or negotiate the right of way. Honda was also determined to focus its area of research in intelligence capabilities, particularly in developing a technology that uses brain signals to control a robot's movements. By 2009, Honda announced that it has developed a new system, the Brain Machine Interface, which allows human to send commands to ASIMO through thought alone. The first-of-its-kind technology uses electroencephalography (EEG) and near-infrared spectroscopy to record brain activity, combined with

1638-428: Is broken, they are relatively free to swing laterally. Under braking load, more work is typically done by the front brakes. If this forward bias is too great, then the front tyres may lose traction, causing understeer. Understeer gradient is one of the main measures for characterizing steady-state cornering behavior. It is involved in other properties such as characteristic speed (the speed for an understeer vehicle where

1729-596: Is for performance engines like the K20A2 or K20Z3 used in the 2002-2006 RSX Type S or the 2006-2011 Civic Si and the second type is for economy engines like the K20A3 or K24A4 used in the 2002-2005 Civic Si or 2003-2007 Accord . The performance i-VTEC system is basically the same as the DOHC VTEC system of the B16A's . Both intake and exhaust cams have three cam lobes per cylinder. However,

1820-400: Is held by the person with whom ASIMO interacts. Its mobility was also significantly improved, making it capable of running at 6 km/h and in circular pattern. By 2007, Honda updated ASIMO with improved intelligence technology that enabled it to operate more autonomously. It could now walk to the nearest charging station to recharge its battery when its power falls under a certain level, and

1911-522: Is necessary to specify the speed and lateral acceleration whenever reporting understeer/oversteer characteristics. Many properties of the vehicle affect the understeer gradient, including tyre cornering stiffness, camber thrust , lateral force compliance steer, self aligning torque , lateral weight transfer , and compliance in the steering system. Weight distribution affects the normal force on each tyre and therefore its grip. These individual contributions can be identified analytically or by measurement in

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2002-406: Is not yet ready for general use. ASIMO have travelled across the globe to appear not only at motor shows and schools but prestigious science and engineering events. To demonstrate its latest capabilities, ASIMO introduced the versatility of the new Honda Insight at the 2009 Geneva Motor Show . It completed 54 rounds of 15-minute public performances over 13 days, running, walking and interacting with

2093-441: Is set to occur at a lower engine speed than the switch-up (representing a hysteretic cycle) to avoid a situation in which the engine is asked to operate continuously at or around the switch-over point. The older approach to timing adjustments is to produce a camshaft with a valve timing profile that is better suited to low-RPM operation. The improvements in low-RPM performance, which is where most street-driven automobiles operate

2184-415: Is shaped similar to a "Y" which allows it to contact two intake valves at once. One primary intake rocker arm corresponds to each secondary intake rocker arm. As a result of this design, there are only six primary intake rocker arms and six secondary intake rocker arms. The earliest VTEC-E implementation is a variation of SOHC VTEC which is used to increase combustion efficiency at low RPM while maintaining

2275-409: Is taken to the grip limit of the tyres, where it is no longer possible to increase lateral acceleration, the vehicle will follow a path with a radius larger than intended. Although the vehicle cannot increase lateral acceleration, it is dynamically stable. When an oversteering vehicle is taken to the grip limit of the tyres, it becomes dynamically unstable with a tendency to spin . Although the vehicle

2366-403: Is the steer angle at which the vehicle would travel about a curve when there is no lateral acceleration required (at negligibly low speed). The Understeer Gradient (U) is the rate of change of the understeer angle with respect to lateral acceleration on a level road for a given steady state operating condition. The vehicle is Understeer if the understeer gradient is positive, Oversteer if

2457-466: Is to change the cam timing profile, of which Honda VTEC was the first successful commercial design for altering the profile in real time. The VTEC system provides the engine with valve timing optimized for both low- and high-RPM operations. In basic form, the single cam lobe and follower/rocker arm of a conventional engine is replaced with a locking multi-part rocker arm and two cam profiles: one optimized for low-RPM stability and fuel efficiency , and

2548-423: Is unstable in open-loop control, a skilled driver can maintain control past the point of instability with countersteering and/or correct use of the throttle or even brakes; this is done purposely in the sport of drifting . If a rear-wheel-drive vehicle has enough power to spin the rear wheels, it can initiate oversteer at any time by sending enough engine power to the wheels that they start spinning. Once traction

2639-399: Is what is happening when a car 'spins out'. A car susceptible to being loose is sometimes known as 'tail happy', as in the way a dog wags its tail when happy and a common problem is fishtailing . In real-world driving, there are continuous changes in speed, acceleration (vehicle braking or accelerating), steering angle, etc. Those changes are all constantly altering the load distribution of

2730-520: The International Organization for Standardization (ISO) in document 8855. Whether the vehicle is understeer or oversteer depends on the rate of change of the understeer angle. The Understeer Angle is the amount of additional steering (at the road wheels, not the hand wheel) that must be added in any given steady-state maneuver beyond the Ackermann steer angle. The Ackermann Steer Angle

2821-478: The J-series ) that includes Honda's cylinder deactivation technology which closes the valves on one bank of (3) cylinders during light load and low speed (below 80 km/h (50 mph)) operation. According to Honda, VCM technology works on the principle that a vehicle only requires a fraction of its power output at cruising speeds. The system electronically deactivates cylinders to reduce fuel consumption. The engine

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2912-419: The poppet valves . The camshaft is surrounded by a partially open drum which has secondary rocker arms attached to it via a pivoting point. These secondary rocker arms, which have a varying depth profile (similar to cams), are directly actuated by the camshaft, in a scissor-like manner. The primary rocker arms are actuated by the secondary (drum attached) rocker arms. The drum will only rotate to advance or retard

3003-680: The 1.3-liter i-VTEC engine uses a 3-stage valve design, an advancement from the 2005 i-VTEC technology. Aside from weight and friction reduction, the engine operates on either low-speed timing, high-output timing or 4-cylinder idling when the VCM system is engaged, each yielding better engine output upon varying driving conditions. Its competency helped place the Honda Civic Hybrid as the third "Greenest Vehicle" in 2009. It can be found on most of Honda's new vehicles in showrooms and roads. Earth Dreams Technology are modifications to increase fuel-efficiency in

3094-505: The 1.8-liter i-VTEC engine for the Civic which could deliver accelerated performance equivalent to a 2.0-liter engine with fuel efficiency that is 6% better than the 1.7-liter Civic engine. The high power output with low emissions and fuel economy is largely contributed by the improvements in several areas: The i-VTEC technology is also integrated into Honda's hybrid vehicles to work in tandem with an electric motor . In Honda's 2006 Civic Hybrid,

3185-616: The 2011 (271 hp SOHC 3.5L) V6 Accord are 24 mpg combined vs. 27 in the two 4-cylinder-equipped models. i-VTEC VCM was also used in the 1.3-liter LDA engine used in the 2001-2005 Honda Civic Hybrid . A version of i-VTEC with direct injection , first used in 2004 Honda Stream . Direct injection 2.0L DOHC i-VTEC I gasoline engine. The AVTEC ( Advanced VTEC ) engine was first announced in 2006. It combines continuously variable valve lift and timing control with continuously variable phase control. Honda originally planned to produce vehicles with AVTEC engines within next 3 years. Although it

3276-496: The 2014 VFR800 reintroduced the VTEC system from the 2002-2009 VFR motorcycle. Oversteer Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of the vehicle to changes in steering angle associated with changes in lateral acceleration. This sensitivity is defined for a level road for a given steady state operating condition by the Society of Automotive Engineers (SAE) in document J670 and by

3367-534: The ACE will be a standard feature in all their passenger cars, regardless of size or price. G-CON is also designed to improve pedestrian safety by minimizing head and chest injuries of the pedestrian during an accident. The company introduced an advanced test dummy, Polar III , which represents the human body and is equipped with sensors to measure the impact of energy on a human body during a car accident. The data obtained has been used to explore pedestrian safety by improving

3458-538: The Japanese market produces 197 bhp (147 kW; 200 PS) using a B18C 1.8-litre engine, producing more horsepower per litre than most super-cars at the time. Honda has also continued to develop other varieties and today offers several varieties of VTEC, such as i-VTEC and i-VTEC Hybrid. Honda also applied the system to SOHC (single overhead camshaft) engines such as the D-Series and J-Series Engines, which share

3549-485: The Japanese market-only Honda CB400SF Super Four HYPER VTEC, introduced in 1999, the first worldwide implementation of VTEC technology in a motorcycle occurred with the introduction of Honda's VFR800 sportbike in 2002. Similar to the SOHC VTEC-E style, one intake valve remains closed until a threshold of 6800 (6600 after 2006) RPM is reached, then the second valve is opened by an oil-pressure actuated pin. The dwell of

3640-443: The VTEC switching piston, while the secondary rocker arm contains the return spring. The term "primary" does not refer to which rocker arm forces the valve down during low-RPM engine operation. Rather, it refers to the rocker arm which contains the VTEC switching piston and receives oil from the rocker shaft. The primary exhaust rocker arm contacts a low-profile camshaft lobe during low-RPM engine operation. Once VTEC engagement occurs,

3731-655: The VTEC-E is used in the F23A, F22B and JDM F20B SOHC VTEC engines. 3-Stage VTEC is a version that employs three different cam profiles to control intake valve timing and lift. Due to this version of VTEC being designed around a SOHC valve head, space was limited; so VTEC can modify only the opening and closing of the intake valves. The low-end fuel economy improvements of VTEC-E and the performance of conventional VTEC are combined in this application. From idle to 2500-3000 RPM, depending on load conditions, one intake valve fully opens while

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3822-561: The car body is designed to absorb and disperse crash energy throughout the energy compartment. When impact absorption is maximised, the cabin intrusion is automatically minimised to effectively lessen injuries to both occupants and pedestrians. To optimize front collision performance and reduce the impact when different sized vehicles collide, the G-CON technology is further developed to incorporate Advanced Compatibility Engineering, Honda's term for crash compatibility. Honda has announced that by 2009,

3913-601: The cars scoring five-star ratings in front and side crash tests. A new independent crash test report from Euro NCAP also assessed the 2009 Honda Accord, Honda Civic and Honda Jazz as among Europe's safest cars, with an overall five-star rating. The Vehicle Stability Assist (VSA) was introduced by Honda to its vehicles in 1997. The term is Honda's version of Electronic Stability Control (ESC), an active safety feature developed to correct oversteer and understeer by using several sensors to detect loss of steering control and traction while simultaneously braking individual wheels to help

4004-559: The center lobe on the camshaft cannot be utilized by both the intake and the exhaust, limiting the VTEC feature to one side. However, beginning with the J37A2 3.7L SOHC V6 engine introduced on all 2009-2012 Acura RL SH-AWD models, SOHC VTEC was incorporated for use with intake and exhaust valves, using a total of six cam lobes and six rocker arms per cylinder. The intake and exhaust rocker shafts contain primary and secondary intake and exhaust rocker arms, respectively. The primary rocker arm contains

4095-418: The center of mass is moved rearward, the understeer gradient tends to decrease. The shifting of the center of mass is proportional to acceleration and affected by the height of the center of mass. When braking, more of the vehicles weight (load) is put on the front tyres and an less on the rear tyres. Conversely, when the vehicle accelerates, the opposite happens, the weight shifts to the rear tires. Similarly, as

4186-586: The center of mass of the load is shifted from one side to the other, the inside or outside tyres traction changes. In extreme cases, the inside or front tyres may completely lift off the ground, eliminating or reducing the steering input that can be transferred to the ground. While weight distribution and suspension geometry have the greatest effect on measured understeer gradient in a steady-state test, power distribution, brake bias and front-rear weight transfer will also affect which wheels lose traction first in many real-world scenarios. When an understeering vehicle

4277-481: The crowd. VTEC VTEC (described as Variable Valve Timing & Lift Electronic Control , but stands for Valve Timing Electronically Controlled ) is a system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine , resulting in higher performance at high RPM, and lower fuel consumption at low RPM. The VTEC system uses two (or occasionally three ) camshaft profiles and hydraulically selects between profiles. It

4368-407: The cylinder and allows for a leaner fuel mixture to be used. As the engine's speed and load increase, both valves are needed to supply a sufficient mixture. When engaging VTEC mode, a pre-defined threshold for MPH (must be moving), RPM and load must be met before the computer actuates a solenoid which directs pressurized oil into a sliding pin, just like with the original VTEC. This sliding pin connects

4459-523: The design of the vehicles. Honda also ventures into advanced mobility research where the findings were used to create ASIMO (Advanced Step in Innovative Mobility), the world's first humanoid robot, as well as Honda's first venture into flight mobility on 3 December 2003, which is HondaJet . ASIMO , derived from Advanced Step in Innovative Mobility, is pronounced ashimo. It was originally

4550-601: The engine as the main power source and an electric motor as an assisting power during acceleration. It was first designed for the Honda Insight in 1999, which combined the electric motor with a smaller displacement VTEC engine and a lightweight aluminium body with improved aerodynamics. Low emissions target was realized when the car achieved the EU2000. In 2001, the Honda Insight Integrated Motor Assist system

4641-412: The exhaust cam. At low RPM only one valve on the intake opens fully, promoting combustion chamber swirl and improved fuel atomization. This allows a leaner air/fuel mixture to be used, improving fuel economy. At higher RPM, both intake valves run off the larger intake cam lobe, improving total air flow and top-end power. The two types of engines are easily distinguishable by the factory rated power output:

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4732-563: The exhaust profile instead of the intake, marking the end of the 'traditional sound' of VTEC in this engine. VTEC implementation on the exhaust rocker arms causes the turbo to be spooled quicker, eliminating turbo lag. VTEC Turbo engines come in three displacement capacities: a 1.0 liter 3-cylinder, a 1.5 liter 4-cylinder , and a 2.0 liter 4-cylinder . Initial implementation for European vehicles included 2-litre 4-cylinder turbocharged engine used from 2015 Honda Civic Type R until present, which included Euro 6 emissions compliance. Apart from

4823-404: The front tyres will keep the front of the vehicle on the desired path but the rear tyres will slip and follow a path with a greater radius. The back end will swing out and the vehicle will turn toward the inside of the curve. If the steering angle is not changed, then the front wheels will trace out a smaller and smaller circle while the rear wheels continue to swing around the front of the car. This

4914-554: The ignition spark, the optimal valve timing, lift and duration settings under low RPM engine operations are very different from those under high RPM. Optimal low RPM valve timing lift and duration settings would result in insufficient filling of the cylinder with fuel and air at high RPM, thus greatly limiting engine power output. Conversely, optimal high RPM valve timing lift and duration settings would result in very rough low RPM operation and difficult idling. The ideal engine would have fully variable valve timing, lift and duration, in which

5005-544: The intake and exhaust valves are actuated by lobes on a camshaft. The shape of the lobes determines the timing, lift and duration of each valve. Timing refers to an angle measurement of when a valve is opened or closed with respect to the piston position (BTDC or ATDC). Lift refers to how much the valve is opened. Duration refers to how long the valve is kept open. Due to the behavior of the working fluid (air and fuel mixture) before and after combustion, which have physical limitations on their flow, as well as their interaction with

5096-496: The intake camshaft is now capable of advancing between 25 and 50 degrees, depending upon engine configuration. Phasing is implemented by a computer-controlled, oil-driven adjustable cam sprocket. Both engine load and RPM affect VTEC. The intake phase varies from fully retarded at idle to somewhat advanced at full throttle and low RPM. The effect is further optimization of torque output, especially at low and midrange RPM. There are two types of i-VTEC K series engines which are explained in

5187-551: The intake camshaft of DOHC VTEC engines. The technology first appeared on Honda's K-series four-cylinder engine family in 2001 (In the United States, the technology debuted on the 2002 Honda CR-V). What is this referring to: The new mechanism debuted in 2003 with the V6 3.0-liter i-VTEC engine which used a new Variable Cylinder Management (VCM) technology that runs on six cylinders during acceleration but used only three cylinders during cruising and low engine loads. In 2006, Honda introduced

5278-437: The intake rocker arm followers together so that, now, both intake valves are following the "normal" camshaft lobe instead of just one of them. When in VTEC, since the "normal" cam lobe has the same timing and lift as the intake cam lobes of the SOHC non-VTEC engines, both engines have identical performance in the upper powerband assuming everything else is the same. This variant of the VTEC-E is used in some D-series engines. With

5369-417: The later VTEC-E implementations, the only difference it has with the earlier VTEC-E is that the second normal cam profile has been replaced with a more aggressive cam profile which is identical to the original VTEC high-speed cam profile. This in essence supersedes VTEC and the earlier VTEC-E implementations since the fuel and low RPM torque benefits of the earlier VTEC-E are combined with the high performance of

5460-425: The lateral and longitudinal forces, a function of the normal force and coefficient of friction. If the lateral and longitudinal forces presented at the tyre during operations exceeds the tyre's available traction force then the tyre is said to be saturated and will loose its grip on the ground and start to slip. Push (plow) can be understood as a condition where, while cornering, the front tyres become saturated before

5551-411: The left and front wheels to decrease. When the vehicle steers outwards from the intended trajectory, VSA intervenes by reducing engine power and if necessary, also braking the inner front wheel Honda's G-CON technology aims to protect car occupants by controlling G-forces during a collision. Such collision safety is a result of specific impact absorption by the vehicle's body and frame. The structure of

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5642-406: The limiting friction case in which either the front or rear wheels become saturated first. It is best to use race driver's descriptive terms "push (plow) and loose (spin)" for limit behavior so that these concepts are not confused. Tyres transmit lateral (side to side) and longitudinal (front to back) forces to the ground. The total traction force (grip) available to the a tyre is the vector sum of

5733-409: The measurement methods. Results depend on the type of test, so simply giving a deg/g value is not sufficient; it is also necessary to indicate the type of procedure used to measure the gradient. Vehicles are inherently nonlinear systems , and it is normal for U to vary over the range of testing. It is possible for a vehicle to show understeer in some conditions and oversteer in others. Therefore, it

5824-464: The microprocessor control. The target of this integrated system was to meet improvements in several areas: With the IMA system, the amount of energy regeneration during deceleration is optimized and friction is reduced. The recovered energy is used to supplement the engine's output during acceleration. The IMA supports the engine during a low rpm normal driving range by utilizing the electric motor to generate

5915-408: The mid range performance of non-vtec engines. VTEC-E is the first version of VTEC to employ the use of roller rocker arms and because of that, it forgoes the need for having 3 intake lobes for actuating the two valves—two lobes for non-VTEC operation (one small and one medium-sized lobe) and one lobe for VTEC operation (the biggest lobe). Instead, there are two different intake cam profiles per cylinder:

6006-406: The next section. Honda's J-Series SOHC engines use an entirely different system also, confusingly, marketed as i-VTEC. Honda J-Series Engines using i-VTEC combine SOHC VTEC operation with Honda VCM (Variable Cylinder Management) variable displacement technology to improve fuel economy under light loads. The K-Series engines have two different types of i-VTEC system implementations. The first type

6097-409: The oil pressure flowing from the exhaust rocker shaft into the primary exhaust rocker arm forces the VTEC switching piston into the secondary exhaust rocker arm, thereby locking both exhaust rocker arms together. The high-profile camshaft lobe which normally contacts the secondary exhaust rocker arm alone during low-RPM engine operation is able to move both exhaust rocker arms together which are locked as

6188-432: The original VTEC. There are 3 intake cam lobes: 2 for the low-RPM mode (1 for almost closed valve, 1 for normally opened) and 1 for the powerful mode when the VTEC solenoid is activated. The lowest RPM for activating the VTEC is 2500, or it may be higher if the load is weak - ECM dependant. With the VTEC solenoid is on the 3-rd biggest lobe begins to push all the intake valves with the more aggressively profile. This variant of

6279-491: The other designed to maximize high-RPM power output. The switching operation between the two cam lobes is controlled by the ECU , which takes account of engine oil pressure, engine temperature, vehicle speed, engine speed, and throttle position. Using these inputs, the ECU is programmed to switch from the low-lift to the high-lift cam lobes when certain conditions are met. At the switch point,

6370-464: The other opens just slightly, enough to prevent pooling of fuel behind the valve, also called 12-valve mode. This 12 Valve mode results in swirl of the intake charge which increases combustion efficiency, resulting in improved low end torque and better fuel economy. At 3000-5400 RPM, depending on load, one of the VTEC solenoids engages, which causes the second valve to lock onto the first valve's camshaft lobe. Also called 16-valve mode, this method resembles

6461-461: The performance engines make around 200 hp (150 kW) or more in stock form, while the economy engines do not make much more than 160 hp (120 kW). The i-VTEC system in the R-Series engine uses a modified SOHC VTEC system consisting of one small and two large lobes. The large lobes operate the intake valves directly while the small lobe is engaged during VTEC. Unlike typical VTEC systems,

6552-567: The performance of their smaller engine designs. One method for increasing performance into a static displacement includes forced induction , as with models such as the Toyota Supra and Nissan 300ZX , which used turbocharger applications, and the Toyota MR2 , which used a supercharger for some model years. Another approach is the rotary engine used in the Mazda RX-7 and RX-8 . A third option

6643-552: The position of the secondary rocker arms, to take advantage of their varying profiles. Thus, through varying the position of the drum about its axis, each cam profile is changed to an optimal height for maximum engine performance without sacrificing fuel efficiency at lower speeds. The VTEC TURBO engine series were introduced in 2013 as part of the Earth Dreams Technology range and include new features such as gasoline direct injection, turbochargers, Dual Cam VTC and VTEC on

6734-548: The prototypes progressed to slightly more man-like walking robots. P1 was introduced in 1993, and subsequently P2 and P3 were presented in 1996 and 1997. The P3 robot was a gawky prototype standing at 160 cm tall and weighed 130 kg. In 2000, ASIMO was unveiled as a robot with real-time, flexible walking technology which enables it to walk, run, climb and descend stairs. It is also built in with sound, face, posture, environment and movement recognition technology, and could even respond to Internet connectivity to report news and

6825-551: The range of 10% by selected use of DOHC, variable timing control (VTC), bore pitch, direct injection, reduced cylinder block and camshaft thickness, reduced engine weight, Atkinson cycle , friction reduction, high-capacity exhaust gas re-circulation (EGR) and electric water pumps. The Integrated Motor Assist, or IMA as it is commonly known, is Honda's hybrid car technology that uses a gasoline-electric drive system developed to achieve higher fuel economy and low exhaust emissions without compromising engine efficiency. The IMA system uses

6916-409: The rear and slip first. Since the front tyres cannot provide any additional lateral force and the rear tyres can, the front of the vehicle will follow a path of greater radius than the rear and if there are no changes to the steering angle (i.e. the steering wheel stays in the same position), the vehicle's front will slide to the outside of the curve. If the rear tyres become saturated before the front,

7007-415: The rear end of the vehicle will spin out because the rotational speed of the rear wheels exceeds the front wheels. VSA will prevent the vehicle from spinning by braking the outer front wheel to produce an outward moment and stabilize the vehicle. Controlling understeer - During understeer, the front wheels lose traction during cornering due to excessive throttle and this causes the speed difference between

7098-413: The second rocker arm has a movable pivot point, thereby providing the varying cam lift. Advanced VTEC motors still use the now standard oil pressure controlled variable cam gear angle mechanism. With these two technologies combined Honda has developed an infinitely variable valve timing and lift system ("VVTL"). Previous versions of VTEC included only staged VVTL i.e. High-Low. With the introduction of i-VTEC

7189-527: The system in the R-Series engine operates in a 'reverse' fashion engaging only at low to mid RPMs. At low RPMs, the small lobe locks onto one of the larger lobes and keeps one of the intake valves partially open during the compression cycle, similar to the Atkinson cycle . The ability for Honda to switch between Atkinson cycle and normal cycle allows excellent fuel efficiency without sacrificing too much performance. In 2003, Honda introduced an i-VTEC V6 (an update of

7280-482: The systems gained infinitely variable valve timing but still only staged lift i.e. High-Low. The "infinitely variable" portion of the A-VTEC is what makes it stand out as a serious evolutionary step in the world of VTEC. A related U.S. patent (6,968,819) was filed on January 5, 2005. Advanced VTEC has a standard camshaft and rocker arms, attached as they normally are with camshaft overhead, and rocker arms pushing down on

7371-605: The understeer gradient is negative, and Neutral steer if the understeer gradient is zero. Car and motorsport enthusiasts often use the terminology informally in magazines and blogs to describe vehicle response to steering in a variety of manoueuvres. Several tests can be used to determine understeer gradient: constant radius (repeat tests at different speeds), constant speed (repeat tests with different steering angles), or constant steer (repeat tests at different speeds). Formal descriptions of these three kinds of testing are provided by ISO. Gillespie goes into some detail on two of

7462-604: The valves remains unchanged, as in the automobile VTEC-E, and little extra power is produced, but with a smoothing-out of the torque curve. Critics maintain that VTEC adds little to the VFR experience, while increasing the engine's complexity. Honda seemed to agree, as their VFR1200, a model announced in October 2009, came to replace the VFR800, which abandons the VTEC concept in favor of a large capacity narrow-vee "unicam", i.e., SOHC, engine. However,

7553-519: The valves would always open at exactly the right point, lift high enough and stay open just the right amount of time for the engine speed and load in use. VTEC was introduced as a DOHC (dual overhead camshaft) system in Japan in the 1989 Honda Integra XSi, which used the 160 bhp (120 kW) B16A engine. The same year, Europe saw the arrival of VTEC in the Honda Civic and Honda CRX 1.6i-VT, using

7644-511: The valvetrain has the added benefit of roller rockers and VTC continuously variable intake cam timing. Performance i-VTEC is a combination of conventional DOHC VTEC with VTC (which operates for intake valves only). The VTC is available in the economy and performance i-VTEC engines. The economy i-VTEC used in K20A3/K24A4 engines is more like the SOHC VTEC-E in that the intake cam has only two lobes, one very small and one larger, as well as no VTEC on

7735-755: The vehicle moves forward. When brakes are applied, the IMA system shuts off the engine and conserved power from the electric motor is utilized. This minimizes vibration of the car body and saves fuel when the engine is idling. When the brakes are released, the electric motor will restart the engine. Among the Honda car models that are using IMA: Honda J-VX (model 1997 concept car) Honda Insight (model 1999–2006, 2010–2014) Honda Dualnote (model 2001 concept car) Honda Civic Hybrid (model 2003–2016) Honda Accord Hybrid (model 2005–2007) Honda CR-Z (model 2009–2016) Honda operates two crash test laboratories to improve safety designs and technologies in their vehicles, resulting in

7826-522: The vehicle regain stability. VSA combines the Anti-lock Braking System (ABS) and Traction Control System (TCS) with side-slip control to help stabilize the vehicle whenever it turns more or less than desired. ABS is an existing system that prevents the vehicle's wheels from locking up under braking, especially in slippery road conditions. For the ABS to work, the system relies on the computed input from

7917-412: The vehicle, which, along with changes in tyre temperatures and road surface conditions are is constantly changing the maximum traction force available at each tyre. Generally, though, it is changes to the center of mass which cause tyre saturation and inform limit handling characteristics. If the center of mass is moved forward, the understeer gradient tends to increase due to tyre load sensitivity . When

8008-474: The weather. By 2004, Honda announced new technologies that target a higher level of mobility which enabled the next-gen ASIMO to function and interact with people more naturally. The new technologies introduced include: With 2005's ASIMO model, Honda added advanced level of physical capabilities that allows ASIMO to operate in real-life environments and in sync with people. The new ASIMO weighed 54 kg and stood at 130 cm tall. It could carry objects using

8099-483: Was declared "Best New Technology" by the Automobile Journalists Association of Canada (AJAC). The development of the IMA system is a result of optimizing the various technologies that Honda has built over the years, including the lean-burn combustion, low-emission engines, variable valve timing, high-efficiency electric motors, regenerative braking, nickel-metal hydride (Ni-MH) battery technology and

8190-402: Was invented by Honda engineer Ikuo Kajitani. It is distinctly different from standard VVT ( variable valve timing ) systems which change only the valve timings and do not change the camshaft profile or valve lift in any way. Japan levies a tax based on engine displacement , and Japanese auto manufacturers have correspondingly focused their research and development efforts toward improving

8281-476: Was speculated that it would first be used in 2008 Honda Accord, the vehicle instead utilizes the existing i-VTEC system. As of late 2017, no Honda vehicles use the AVTEC system. Honda's advanced VTEC technology departs greatly from its previous incarnations by no longer relying on switching between two sets of lobes on a given camshaft . It instead uses a single cam lobe per valve, and two rocker arms per valve whereby

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