Relentless
Well Known Member
Getting many questions about my comments about "pressure recover plenum" so here is more detail on this effort.
There are fundamentally two areas that make the separate plenum concept
work well
1.) Temperature
2.) Pressure/Volume
Firstly, temperature.
In the standard arrangement we have four inlet tubes that are cast into
the engine oil sump. By design, this arrangement will subject the
incoming air to the to the oil temperature which at operating temp will
be in the region of 90deg C.
Using a standard day at 15 deg C, you can see that an engine that is
taking in air at around 50 deg C or more, is less dense, which means
less power. If we separate the induction so that we can draw in cool air
directly then we will obtain the benefit of dense air and with it the a
corresponding increase in power.
Secondly Pressure/Volume
The air box (plenum) diffuses the air, decreases the velocity and
increases the pressure. Therefore increased amounts of air can be
inducted with an air box (plenum) Using resonance tubes (intake tubes)
we are able to increase mid and high end performance.
Fundamentally there are two types of induction tuning, inertia and
resonance. Inertia tuning is the domain of the inlet tract length and
dia and the resonance by the air box (plenum), technically called a
Helmholtz resonator.
Cylinder filling and charging at a certain speed is dependant on the
system resonance frequency (which is dependent on the valve being open
or closed)
Without using such an airbox (plenum) we would not be able to tune the
system effectively.
When we designed the plenum we used mathematical optimization models and
CFD,it allowed us a close approximation to an optimized product.
To answer the question quickly:
The air box (plenum) diffuses the air, decreases the velocity and
increases the pressure. Therefore increased amounts of air can be
inducted with an air box (plenum) Using resonance tubes (intake tubes)
along with a significant reduction in air temperature, we are able to
increase mid and high end performance.
Latest version working with integrated EFii injector bosses:
There are fundamentally two areas that make the separate plenum concept
work well
1.) Temperature
2.) Pressure/Volume
Firstly, temperature.
In the standard arrangement we have four inlet tubes that are cast into
the engine oil sump. By design, this arrangement will subject the
incoming air to the to the oil temperature which at operating temp will
be in the region of 90deg C.
Using a standard day at 15 deg C, you can see that an engine that is
taking in air at around 50 deg C or more, is less dense, which means
less power. If we separate the induction so that we can draw in cool air
directly then we will obtain the benefit of dense air and with it the a
corresponding increase in power.
Secondly Pressure/Volume
The air box (plenum) diffuses the air, decreases the velocity and
increases the pressure. Therefore increased amounts of air can be
inducted with an air box (plenum) Using resonance tubes (intake tubes)
we are able to increase mid and high end performance.
Fundamentally there are two types of induction tuning, inertia and
resonance. Inertia tuning is the domain of the inlet tract length and
dia and the resonance by the air box (plenum), technically called a
Helmholtz resonator.
Cylinder filling and charging at a certain speed is dependant on the
system resonance frequency (which is dependent on the valve being open
or closed)
Without using such an airbox (plenum) we would not be able to tune the
system effectively.
When we designed the plenum we used mathematical optimization models and
CFD,it allowed us a close approximation to an optimized product.
To answer the question quickly:
The air box (plenum) diffuses the air, decreases the velocity and
increases the pressure. Therefore increased amounts of air can be
inducted with an air box (plenum) Using resonance tubes (intake tubes)
along with a significant reduction in air temperature, we are able to
increase mid and high end performance.
Latest version working with integrated EFii injector bosses: