Air Induction Systems

More documents

Recommendations

Info

Air intakes design is important to minimizenoise, and the quantity of dirt and water enteringthe air filter. They are used to also optimizetheairflow into the engineAir intakes ideally should have minimal bendingand smooth interior surfaces for maximumairflow.Resonator boxes or chambers may be located onthe intake system in passenger applications toinject pressure waves which cancel intake noisefrom created from the large amount of valveoverlap that is characteristic of a diesel engine.Above: A gasoline engine with water injectionthrough the intake manifold – these systemscan enhance performance by allowing for highercompression ratios or advanced timing. Indiesels, higher fuel rates can be used with thewater as a combustion chamber coolant. Thistechnology also reduces N0x emissionsSee also: http://www.frii.com/~maphill/wi.htmlIntakesFactors Affecting Air IntakeEfficiency:• Smoothness of air intake passages.• Degree and number of bends in air passages.• Size, design (Crossflow Vs Uniflow) of portsand passages.• Valve timing, lift and duration of valveopening.Because diesel engines often have largeamounts of valve overlap, some exhaust gasesmay leak by the intake valve during overlap.Soot loading of an intake manifold is normal ina diesel. Intake noise is louder in a diesel for thesame reason. The intake valve can become veryhot to the point of being damaged. Valveadjustment is important!Lack of sufficient airflow to an enginecan result in these conditions:- Low turbocharger or blower boost pressure- Higher exhaust temperatures- Incomplete combustion- Lower fuel economy- Lack of power- Smoke at the exhaust stack- Increased exhaust emissions- Shorter valve and piston life- Increased lube oil useMany current engines, which are electronicallycontrolled, are equipped with a variety of airinlet system sensors. These three sensors canhelp identify a problem in the intake system andcause the engine ECM to adapt protection orperformance strategies. For example, intake air
temperature is monitored on many engines toprevent damage from high intake temperatures.Typically, the engine power will be de-rated iftemperatures are excessive.Other intake air sensor strategies include:• Ambient air pressure sensor (barometricpressure sensor) for altitude compensation.• Intake manifold temperature sensor. This isdata is used to modify fuel timing/injection ratesto minimize emissions and is monitored by theengine protection system in the event of excessintake temperature• Turbocharger boost pressure sensor; data usedto adjust fuel rates and sense engine load.Moisture & Dirt Removal From IntakeAirIntake systems can be designed a number ofways to minimize the entry of moisture and dirtentry into the air induction system.A frontal intake system alone with inlets closeto the ground will results in more ingestion ofroad salt and water into the air intake. Waterwill dissolve the salt and allow it to passthrough the induction system causing corrosionto components like the aluminium intercoolerand eventually cylinder component damage.Below: frontal air intake system withinduction passage through the hood.Note the dirt-air drainAbove: Side mounted intake systemseliminate more moisture and dirtaspiration than frontal systemsbutlose the “Ram Air” effect
Page 1: Air Induction SystemsAir Supply Req
Page 6: air deflected by the windshield to
Page 9 and 10: separate/integral restriction gauge
Page 11: • Improved contaminant encapsulat

Air Induction Systems

Create successful ePaper yourself

Delete template?

Save as template?