Two weeks back from SEMA and although last week I mentioned
the technological increase we noted at the show, there was also quite a few new
manufacturers present and exhibiting. This is somewhat surprising as finding a
manufacturer to build you intercoolers, turbos, etc.. isn’t exactly hard and at
the same time SEMA isn’t exactly inexpensive to showcase your capabilities. So
I was a bit surprised in retrospect with what we saw. That being said it’s a
great time to talk to people who do one thing and do it really well and pick
their brain for information!
The more you know:
Seems there is no limit to how often I learn something new and realize how much
more there is yet to learn in that subject. Take intercoolers for example,
there’s basically two options in the market place for most of us; either a drop
in factory location replacement, or an aftermarket front mounted intercooler.
Each has its benefits and determents so let’s cover each briefly and then
consider some of the infrequently discussed aspects of intercooler as a whole.
Front mount intercoolers or FMIC’s are exactly what they sound like, an
aftermarket intercooler that is fastened to the front of the vehicle (typically
right behind the bumper or air guide) and routed with piping to the turbo
outlet and to the throttle body inlet on the intake manifold. As you might
guess this mounting configuration has benefit since the intercooler is not
obscured by any other heat exchangers (radiator or condenser) however it does
increase the total amount of plumbing length which in turn tends to increase
turbo lag a bit. Additionally FMIC’s tend to be wide and thick but typically
shorter in height. This added thickness (upto and in some cases more than 3”)
can reduce efficiency at low speeds since higher airflow is required to
permeate the intercooler and provide its maximum gain.
Stock mount replacement:
Aftermarket intercoolers that replace the stock unit and mount in the same
location do bring a great deal of simplicity to the addition of an intercooler.
Since they fit in the stock location the install is typically straight forward
and little to no modifications are necessary to make them fit. Some FMIC kits
are 100% bolt up but many ‘ebay’ kits are not. Additionally since there is more
area (width and height) in the stock mounting configuration this provides a
thinner intercooler core which promotes better cooling at lower speeds. Of
course being behind the condenser this can allow some heat from the A/C system
to be transferred to the intercooler but in most cases this isn’t as big of a
concern unless your climate has considerably higher ambient temperatures.
A lot of the decision making, when it comes to choosing what
intercooler is right for you, will based on how far you plan on modifying the
car with respect to performance upgrades. For vehicles that will stay within
the TD04 family of turbos (16T, 18T, 19T) a stock drop in cooler may be the
best option since these turbos tend to develop higher charge temperatures quite
early in the RPM band vs. a larger turbo such as a GT3071. So the benefit of
lower speed cooling becomes a very desirable side effect. For those who are
planning a larger build on their vehicle and are looking to turbos that may not
start spooling until 3500+ rpm then the FMIC may make more sense. These larger
turbos won’t be spooling in the early PRM range which means by the time they
are developing significant boost the vehicle is likely up to some speed
already. The added total volume of plumbing with an FMIC is not as critical
either since a larger turbo can fill the added volume much easier.
While intercooler dimension and placement is of concern it shouldn’t over
shadow additional considerations like pressure drop, efficiency of the
intercooler as a heat exchanger, and material construction/design. There’s more
than a few poorly produced intercoolers our there so do your homework and ask
questions. If a vendor can’t supply the answers you might want to look
Pressure drop is exactly what it sounds like, the amount of
pressure lost due to the amount of internal restriction in the intercooler. Pressure
drop is a function of tube count/size and fin stack inside the intercooler. The
type of internal tubing used is a factor as well with bar & plate or Delta
fin being the more popular as compare to tube and fin designs although this is
somewhat debated by those in the know. Look for pressure drop figures at
highest effective efficiency and you’ll have a good comparison to go by.
The efficiency of the intercooler is also affected by design
of the end tanks, the more smooth the end tank transition typically the more
laminar (non-turbulent) the air flow. If it looks clunky… it probably is.
Still want more info? Check out the intercooler tech page at