2016+ Civic OE Intercooler System Breakdown Pt.1

You’ve seen the teaser post on social and now we have this blog breaking down the OE intercooler system found on your 10th Generation Honda Civic, so it’s probably obvious that we have an awesome project in the works for the CivicX community, but let’s not get ahead of ourselves. To design, test and validate a performance intercooler system, we must first understand the OE intercooler system and all its strengths and weaknesses.

Common FMIC terminology

Common FMIC terminology

First, let me introduce a term that will be used frequently in the coming blogs.  

“FMIC” =  Front Mount Intercooler

The FMIC System consists of three major sub-systems:

  1. Hot Pipe Section: This is the section of piping between the turbocharger compressor cover outlet and the intercooler inlet. This is called the “Hot Pipe” section because the boosted airflow passing through this piping has been heated by the turbocharger and has not yet been cooled by the intercooler.

  2. Intercooler: This is the heat exchanger (similar to a radiator) that cools the boosted airflow. It consists of an inlet and outlet end-tank and a bar and plate heat exchanger core.  

  3. Cold Pipe Section: This is the section of piping between the intercooler outlet and the throttle body.  This is called the “Cold Pipe” section because the boosted airflow passing through this pipe has been cooled by the intercooler and, ideally, is as close to outside air temperature as possible.

Let’s further breakdown each sub-system starting with the Hot Pipe Section.


The OE Hot Pipe Section is fairly basic and relatively short which is a good thing. This is where the benefits of the OE design stops. The rubber hose consists of 1-ply of reinforcement braiding which will support stock boost levels of 16-19psi but at increased boost pressures common with a tuner the OE hose will start to expand. This causes boost lag and poor response. However, this is nothing compared to the major performance issue of the OE Hot Pipe; It’s so SMALL! The inner diameter of the pipe is 1.57 inches and will be a major restriction on power with increased boost pressure and especially with an upgraded turbo kit.


Continuing along the air path through the FMIC System we next encounter the OE Intercooler. it consists of three major parts; the Inlet End-tank, Core, and Outlet End-tank. Each end-tank is an injection molded plastic that is attached to the core with a stamped metal banding. On the Honda Civic, each endtank is a very different design due to the packaging and routing of the FMIC System in the vehicle.


Matching the Hot Pipe, the Intercooler inlet is a meager 1.65 inches with the intercooler outlet reducing down to 1.57 inches.  The biggest restriction with the OE Intercooler is the core itself due to its size: 4.37in tall x 28.0in width x 2.50in thick. The small size/volume of the core causes two major issues that affect power; Pressure drop across the core and thermal efficiency.  

Pressure drop across the core is the amount of boost pressure lost as the air passes through the intercooler.

For example: boost air enters the core at 25psi and exits the core at 23psi; this is a 2psi pressure drop. This is bad. Now, you’ll never see this in your datalogs with the Hondata or KTuner because there is no pressure sensor in the Hot Pipe Section. The only pressures you can see with OE sensors are the Cold Pipe pre-throttle body and in the intake manifold itself. So how does pressure drop affect power? Without getting into too much detail; the greater the pressure drop through the FMIC System, the more work your turbocharger has to do to hit a boost target, which makes it less efficient.  

Thermal efficiency across the core is the amount of the heat and how long it can remove that heat from the boosted airflow.

The small size/volume of the OE core reaches its thermal capacity very quickly in any type of performance setup. You can see this on a chassis dyno and at the track. Once the OE Intercooler reaches its thermal capacity; its ability to remove heat from the boosted airflow drops drastically…robbing power from your Civic.


We’ve made it through the core and ideally the boosted air has been cooled close to ambient air temperature. Next up is the Cold Pipe Section. The Cold Pipe Section is a bit more complicated with two separate plastic pipes and two separate rubber hoses. Again we see a piping inner diameter of 1.57 inches thought the Cold Pipe Section. What is interesting is the design of one of the rubber hoses. The ribbed and ring reinforced hose has a very important job; it allows flex in the pipe to accommodate the engines drastic amount of movement.

When designing the 27WON piping we will need to consider the engines movement and provide a flexible section. We can’t expect everyone be running a 27WON Performance Rear Motor Mount… ;)

Lastly, the CVT transmission is HUGE and the OE Cold Pipe is tiny so there’s no clearance issue there. However, the 27WON Cold Pipe Section is NOT going to be tiny. We’ll have our work cut out for us to get a proper IC pipe past the transmission.  


For those of you still curious, there are three ports in the Hot Pipe that house a MAP Sensor, Temperature Sensor and Boost Port for the EVAP System. These are all critical for engine control system and must be a part of any performance piping system. Not an Issue ☺

So there you go, we’ve broke-down the OE FMIC System and found that overall it works for the point A-to-B commuter car. Once pushed to perform beyond stock power levels it’s going to fall flat on its face.  

Our goal is to reduce pressure drop through the core, increase thermal capacity and efficiency, and include a performance piping kit that will fit great. The 27WON FMIC kit will well outperform the OE setup and provide necessary cooling for all but the most extremely modified Civic’s .We have some very exciting features going into the design and are working hard on validation of a FMIC system that we will be sharing in coming design blogs. We are positive this will be a kit that raises the bar.

Thanks for tuning in with 27WON Performance.  

Until next time, I Dare You to REDEFINE the Aftermarket.