It does not matter the car, the engine, or the type of fuel you are working with, every internal combustion engine starts at the same place. That place is your air induction system. Whether Turbo, NA, or supercharged, the air needs to get inside your hood and into your engine to make power. Today we look at the 2023 + Honda Civic Type R so we can learn how she breathes.

The turbo 4-cylinder in the Latest-gen CTR is an amazing machine. 315+ horsepower from a factory 2.0L is healthy! While that’s a great start, we are hungry for more.

To do that we’ll take a look at the OEM intake system in the FL5. It starts off exactly like how you would think. A bunch of black plastic with various curves, angles, and shapes in the mix. A large package wedged into the front corner of our engine bay. A mass air flow sensor is after the air filter to precisely measure the air going into the engine. Various tubes protrude out the intake system for emissions-related components. So in a sense, this intake is pretty typical of what we have seen on all new Hondas lately. But is there anything special that helps make this engine take in over 300 ponies?

Taking a closer look at the airbox we can see how air goes in. We see a nice big air inlet which is great. It’s wide at the opening and tapers to a 89 mm by 82mm opening before it goes down into the bottom part of the airbox. We like this design because of the nice rubber seal on top of the inlet. It seals the top of the air inlet against the hood so that the intake is not picking up under-hood air which can be very hot. A simple yet effective way of controlling intake air temperatures.

The new Civic L15 and K20 OEM intakes are similar in that they share how air flows through the airbox and ducting. After the air enters the inlet it goes down, makes a gradual curve, and then up through the bottom of the OEM air filter. From here it is now in the cavity above the filter before it enters a volute where the MAF sensor is housed. We know in order to keep tuning in check that this volute or MAF housing is a very specific and controlled size so the engine knows exactly how much air it’s ingesting.

It’s important that an aftermarket intake match this dimension to OEM so that fuel trims are kept in check

Taking a closer look at the airbox on a component level we see all the individual pieces that make up the airbox. The nice inlet goes into into the bottom of the airbox then through the thick OEM air filter and then through the MAF.

The OE intake is a pretty good intake, perhaps the best OE intake we’ve seen.

It is very well sealed so it does an excellent job at keeping the hot engine air out and the cold air in. It also transitions smoothly. From the inlet to the MAF there are no abrupt turns or sharp angles. It keeps the air moving pretty well.

The only real gripe we have is the accordion-shaped air duct on the way to the turbo. Oh, and it’s too quiet!

After exiting that air duct we get to a small piece of hard plastic. This piece is home to an EVAP purge sensor that uses fresh intake air to help mix with unburned fuel vapors so they can get reintroduced back into the engine for combustion. This helps get lower emissions for regulation purposes. Thankfully this piece is nice and smooth on the inside. Right after the plastic elbow but before the TIP is a last piece of silicone to tie everything together. This area of the intake may or may not have much room for improvement. We will take a close look to see if there is value in upgrading or keeping these pieces OEM. Only testing and running it will tell.

That my friends is a walk through of the really well-rounded OEM intake for the 2023+ FL5 Type R.

We are sinking our teeth into this one to find out if power is really to be had with an aftermarket intake or if the Current Crop of aftermarket “Cold air” or “High Volume” intakes are just there for show.

Guess you will have to stick around and find out. Till next time.

REDEFINE the Aftermarket

-Vincent
Co-Founder

FL5 Air Intake Design Blog Pt.1 - How The K20C1 Breathes