DIY Short Ram Intake for Honda Civic R18 (8th Gen)
Building a custom short ram intake for your R18 Civic delivers an aggressive engine note and better throttle response without spending hundreds on a bolt-on kit.
The Short Answer (TL;DR)
Transforming your 2006-2011 Honda Civic R18 factory intake into a short ram setup requires removing the stock airbox resonator, trimming the factory MAF housing or coupler, and clamping on an aftermarket high-flow cone filter. This 1-hour DIY unlocks deep throttle sound, though pairing it with a dedicated performance intake tube yields better air velocity.
Tools Needed
- Rotary tool (Dremel) with cutting and sanding discs
- 10mm socket and ratchet
- Flathead screwdriver (for hose clamps)
- Phillips screwdriver (for MAF sensor screws)
- High-flow cone air filter (2.75-inch or 3-inch with step-down adapter)
- Heavy-duty worm gear clamps
- Safety glasses and shop rags
The Step-by-Step Process
- Disconnect the Battery & MAF Sensor: Disconnect the negative battery terminal using a 10mm wrench. Carefully depress the locking tab on the Mass Air Flow (MAF) harness connector and unclip it from the factory intake tube.
- Remove Factory Airbox and Resonator: Use your 10mm socket to loosen the bolts holding the upper and lower airbox housing to the chassis. Loosen the intake hose clamp at the throttle body connection and pull the airbox assembly out of the engine bay.
- Isolate and Modify the MAF Housing: Remove the MAF sensor from the factory plastic tube using a Phillips screwdriver and set it aside on a clean cloth. Using a rotary tool, carefully trim away the factory airbox retaining tabs and silencer plastic so the MAF housing can seat securely onto an aftermarket cone filter.
- Clean and Deburr All Edges: Sand down all rough plastic edges around your cuts. Use compressed air and shop towels to thoroughly blow out all plastic shavings and debris. No plastic debris should remain inside the tube where it could get sucked into the throttle body.
- Mount the Cone Filter and Reinstall MAF: Reinstall the factory MAF sensor into the modified housing and tighten the screws firmly. Slide your high-flow cone filter onto the inlet opening of the MAF housing and tighten down the worm-gear clamp until secure.
- Reinstall the Intake Tube and Test: Reattach the intake elbow to the throttle body, secure the hose clamps, and plug the MAF sensor harness back in. Reconnect the battery, start the engine, and inspect for vacuum leaks or loose fittings.
Why You Should Upgrade While You're In There
While cutting the factory airbox produces a throaty induction sound, the factory accordion-style intake tube still causes internal air turbulence. Installing a dedicated aluminum intake pipe paired with a proper heat shield prevents hot engine-bay air from soaking into the intake charge and keeps intake air temperatures (IATs) consistent.
Recommended Upgrade: Cold Air Intake or Polished Aluminum Short Ram System with Heat Shield.
Frequently Asked Questions
Will this custom short ram intake trigger a Check Engine Light?
No, provided the factory MAF housing diameter is retained and the MAF sensor is installed facing the correct airflow direction. If the MAF housing diameter is altered, the ECU will register inaccurate air volume and trigger lean (P0171) or rich (P0172) codes.
Does a short ram intake increase engine bay heat soak?
Yes. Drawing intake air directly from behind the radiator will increase intake air temperatures during idle and stop-and-go driving. Adding a dedicated heat shield or routing ducting from the lower front bumper helps deliver cooler ambient air to the filter.
