Search results
Results from the WOW.Com Content Network
For controlling the amount of mixture, a throttle valve is used, which is why quantity control is also called intake air throttling. Intake air throttling changes the amount of air sucked into the engine, which means that if a stoichiometric ( λ ≈ 1 {\displaystyle \lambda \approx 1} ) air-fuel mixture is desired, the amount of injected fuel ...
The advent of concern about fuel economy and emissions had major impacts on engine design. Some of the trade-offs reduced throttle response. Most new cars employ a drive-by-wire system, which includes electronic throttle control and can itself either reduce or increase throttle response (Depending on whether or not it's being employed on a performance car).
At the extreme, higher-performance cars like the E92 BMW M3 and Ferraris, and high-performance motorcycles like the Yamaha R6, can use a separate throttle body for each cylinder, often called "individual throttle bodies" or ITBs. Although rare in production vehicles, these are common equipment on many racing cars and modified street vehicles.
The butterfly valve often contains a small "idle cutout", a hole that allows small amounts of fuel/air mixture into the engine even when the valve is fully closed, or the carburetor has a separate air bypass with its own idle jet. If the engine is operating under light or no load and low or closed throttle, there is high manifold vacuum.
A typical ETC system consists of three major components: (i) an accelerator pedal module (ideally with two or more independent sensors), (ii) a throttle valve that can be opened and closed by an electric motor (sometimes referred to as an electric or electronic throttle body (ETB)), and (iii) a powertrain or engine control module (PCM or ECM). [4]
Lean-burn refers to the burning of fuel with an excess of air in an internal combustion engine. In lean-burn engines the air–fuel ratio may be as lean as 65:1 (by mass). The air / fuel ratio needed to stoichiometrically combust gasoline, by contrast, is 14.64:1. The excess of air in a lean-burn engine emits far less hydrocarbons.
Better fuel distribution and better fuel charge inside the combustion chamber; During the injection process the fuel gets evaporated, cooling the cylinder chamber; Cooling effect of the pressurized fuel allows for use of a lower octane fuel leading to a cost savings for the end user; Higher compression ratios, which translates into more power
PEM fuel cells are popular in automotive applications due to their relatively low operating temperature and their ability to start up quickly even in below-freezing conditions. [18] As of March 2019 there were 6,558 fuel cell vehicles on the road in the United States, with the Toyota Mirai being the most popular model. [19] PEM fuel cells have ...