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
(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
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.
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
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
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
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 buildup.