INTERCOOLER
What is intercooler heat soak?
Heat soak is when the intercooler can't dissipate
the heat that it absorbs from the turbo fast
enough. When an intercooler can't cool the charge
air by removing the heat from it, it loses its
effectiveness. This explains why turbo cars
tend to run slower or have slightly less power
when the weather is warm.
What is the purpose of an Intercooler?
An intercooler's primary function is to cool
the charge air after it has been heated due
to boosting and the heat that is produced by
the turbo before sending the air into the engine.
As the air is cooled, it becomes denser, and
denser air makes for better combustion (more
power). Additionally, the denser, cooler air
helps reduce the chances of knock.
FMIC, TMIC, SMIC - what do they mean?
(Front Mounted Intercooler, Top Mounted Intercooler,
Side Mounted Intercooler) terms which refer
to the placement of the charge air cooler in
the engine bay and in reference to the engine.
Typically FMICs provide the best cooling capability,
as they are located in front of the radiator
for optimum airflow. SMICs and TMICs are commonly
found on factory-turbo'd cars. TMICs are more
prone to heatsoak as they are placed over the
engine directly in the path of the rising heat
and very close to the hood. However, when a
TMIC is used in conjunction with a hood scoop,
they can provide adequate cooling.
Will an intercooler help make more horsepower?
Yes, although it is only indirectly responsible
for helping make more power. Since the intercooler
increases the charge air density, an intercooled
engine will typically make more power than a
non-intercooled engine with the same setup by
allowing more air to be crammed into each cylinder.
What is the difference between an air-to-air
intercooler and a water-to-air (liquid-to-air)
intercooler?
An Air-to-Air intercooler uses ambient air flowing
over the fins to cool the charge air, while
an Air-to-Water intercooler uses coolant (water)
with a system similar to that of a radiator's
cooling system. Traditionally, air-to-air intercoolers
are used for street applications because of
their lower cost and reduced complexity, while
air-to-water intercoolers are used in race and
packaging-constrained applications.
How do I select the proper intercooler core
size?
A major limiting factor in choosing an intercooler
size is space constraints within the engine
bay. If there is not enough room for an intercooler
with adequate flow, then often a water-to-air
intercooler is used instead to maximize the
cooling capability of the surface area of the
core.
You want to make sure that the intercooler you
choose is large enough to effectively handle
the air. Too small of a core, and you will restrict
the potential of the turbo by not allowing the
charge air to be cooled adequately.
What is the best placement of my intercooler?
The best place for your intercooler is directly
in the path of the inflow of ambient air. Traditionally
this has been right in front of the radiator
in the front of the car, hence the term Front
Mount Intercooler.
Will a FMIC block flow to my radiator?
No. Since the intercooler allows air to pass
through it, airflow to the radiator will not
be blocked. However, using an intercooler core
that is too thick and does not allow air to
pass through it quickly or completely and airflow
to the radiator can be restricted which can
lead to potential overheating problems.
What is intercooler effectiveness and how do
I measure it?
Effectiveness is defined as the ratio of how
many degrees of temperature that were removed
from the charge air by the intercooler to the
original temperature that is put into the charge
air by the turbo.
Example:
If the turbo compresses the charge air to a
temperature of 140° F, but after passing
through the intercooler the air is 115°
cooler (resulting in a 25° F charge air
temperature), the efficiency would be:
Effectiveness: 115/140 = 0.82 or 82% efficiency
Typically, air-to-air intercoolers for normal
street applications range between 60% and 70%
efficiency. Often, liquid-to-air intercoolers
have effectiveness ratings from 75% to 95%.
One common method of improving the cooling of
the charge air dramatically in an air-to-water
intercooler is the inclusion of ice as a coolant.
What exactly is 'pressure drop/loss' / 'flow
loss' and how are they measured?
Pressure loss, or pressure drop, refers to the
change in pressure when comparing the air entering
the intercooler with the exiting air. This change
is mostly affected by the internal flow area
of the intercooler. Flow loss, however, is measured
not just with pressure loss but with how much
restriction to airflow exists.
Maximum performance can be obtained if the pressure
loss is kept below 1.0 to 1.5 psi. Anything
in excess of these numbers, especially higher
than 3.8 psi, and the intercooler is not properly
fitted for the application which results in
hindered performance and dramatically decreased
functionality of the intercooler system itself.
I want to turn up my boost, is a larger intercooler
necessary?
Usually, it is not necessary to upgrade the
intercooler when raising boost levels. The pressure
drop contributed by the intercooler is proportional
to it's flow (CFM) squared. This relationship
shows that it is highly unlikely the change
resulting in loss from higher boost levels will
require a larger intercooler. If there is a
significant change however, such as 40% or 50%,
then a larger intercooler may be necessary.
Is there a maximum amount of boost I can run
on my intercooler?
While it is possible that an intercooler can
fail from boost levels being too high, it is
a very rare scenario. However, if not properly
designed to handle high boost, cracking along
seams and of the endtanks can occur.
How significant is a leak in my intercooler?
For an air-to-air intercooler, a leak, as long
as it is not a significantly large one, will
not hinder performance at all. However, if an
air-to-water intercooler develops a leak in
the main core, it could lead to other more significant
problems with the engine itself. Be sure to
fix these problems as soon as they occur to
prevent other damage.
I want my car to remain a sleeper/stealth.
Can I paint or anodize my intercooler so it
is not easily visible?
Yes! It is not uncommon at all for an intercooler
and endtanks to be anodized black to keep attention
away from the car and help it maintain a sleeper
appearance. A very light coat of paint on the
core and endtanks is also another option, usually
much cheaper and easier than anodizing, with
a negligible performance loss.
Is there any maintenance required for my intercooler?
Are there any special things to do to keep it
working longer?
In a water-to-air intercooler, check the water
level often as this is crucial for the intercooler
to operate properly. In cold weather, just like
a car, it will need antifreeze in order to function
effectively and properly. With an air-to-air
intercooler, there really is no maintenance
that needs to be done other than just the routine
checking of hoses and clamps to make sure everything
is tight. Additionally, the intercooler fins
may be picked-out or de-smashed to ensure maximum
cooling. Every 20,000 miles or so it is recommended
that the intercooler core be inspected, and
if necessary, flushed/washed out to remove any
accumulated oil or