hello everyone and welcome in this video
we're going to be talking about throttle
bodies so what is a throttle body well
this right here is a throttle body and
basically it's located between your air
intake filter and piping and your intake
manifold and acts as a valve restricting
the amount of air that can go into the
engine so this is a mechanical throttle
body so when you press on the gas pedal
what you're doing is you're actually
opening up this valve and allowing for
more air to pass into the intake
manifold and then into the engine so by
allowing more air to go into the engine
you inject more fuel and you create more
power and the revs increase and so on so
why might you want an aftermarket
throttle body well on stock engines the
stock throttle body is typically going
to be a good size to not create much
restriction as far as how much power
it's going to make but if you do have a
modified engine then your throttle body
can become basically a restriction if
it's too small and restricting the
amount of air that goes through so by
getting a larger one you can pass more
air through it and thus create more
horsepower so that's why you may choose
to use an aftermarket throttle body so
let's take a look at some of the
features on this throttle body and what
they're there for
so the first thing we'll be looking at
is the mechanism which actually opens
the butterfly valve so what we've got
here is this is where your cable your
throttle cable is going to route and be
connected up top here and so as you
press down on the gas pedal which is
connected to the throttle cable you'll
be turning this and then opening up the
butterfly valve to allow airflow on the
side we have where the throttle position
Center mounts and so as this valve opens
you can see it will rotate and it will
change the throttle position sensor and
it will know how open the throttle is so
up on top we have the manifold absolute
pressure sensor the map sensor mounting
which mounts right here and then you can
see this hole here which comes down and
then feeds behind throttle plate here so
it's sensing the pressure behind the
throttle plate so as you allow for more
airflow and it will read a higher
pressure and the engine will know to
inject more fuel now on the left side
here we have this throttle body stop
screw and basically what this is doing
is preventing this spring from rotating
the throttle body anymore and this
basically just creates the stop
for where this should stop rotating in
order to fully close the throttle so
this doesn't need to be adjusted it
should be left basically where it is and
that's why you can see that there's a
paint pen mark on it indicating that
it's in the initial position now on the
inside of the front you'll notice this
port here and that's for the IAC valve
which is controlling the amount of air
the engine gets at idle so you've got
this bypass here and then your IAC valve
which we mounted back here can regulate
the amount of air going to the engine at
idle so on cold starts it can allow for
more air and allow the engine to warm up
faster now up on top here we have the
idle adjustment screw and so this can be
screwed in to this port here and allow
for more or less airflow that's always
going to be able to pass the throttle
body to adjust your idle speed with the
engine so basically there's a little
port in here and as you screw that in
you can see the port the idle air
control port has another hole inside of
it and that's a little difficult to see
but there's a hole right there and that
feeds up to this hole and then can come
out as you can see here behind the
throttle plate so as you put this screw
in you're going to be blocking off that
port right there and then minimizing the
amount of air that can come through here
so you can adjust it simply by screwing
it in more or less and that will adjust
the amount of air that can pass around
the throttle plate now on the bottom of
the throttle body you'll notice these
connections here to connect up hoses and
these are actually for coolant lines so
that you can connect up coolant lines to
this and basically what happens is if
you're in like sub-freezing temperatures
and you've got air coming through here
and you might have some condensation
build-up or something like that on the
throttle body that could freeze this
valve closed and so by having these
coolant lines pass through they make
sure to keep that a bit warmer and thus
prevent this from freezing and you may
be thinking wow if you're heating up the
throttle body you're going to be heating
up your intake charge and I mean that's
true to some extent but it's honestly
quite minimal the amount of heat passing
through here is pretty small and
basically you're just putting it enough
so that things won't freeze up but at
the same time you know the surface area
is relatively small and the amount of
heat passing through it is pretty small
so you're not actually going to be
heating up your intake charge
significantly and then on top of the
throttle body you can see this vacuum
line and the little hole there which
it's the
- and this is for emissions control
basically you know some vehicles may or
may not be using this feature of it so
thank you for watching if you have any
questions or comments feel free to leave
them below