FL5 Mods: The Best Upgrades for the Honda Civic Type R, in Order
Quick answer: the best FL5 mods, in order, are a sealed intake and turbo inlet pipe, an ECU tune, a cat-back exhaust, lowering springs or coilovers, lighter wheels with stickier tires, a big brake kit for track use and, last, aero and drivetrain upgrades. The 2023+ Civic Type R (FL5) is already sharp from the factory, with a 315 hp 2.0L turbo engine, a 6-speed manual, a limited-slip differential and adaptive dampers, so the smartest builds fix heat soak and add sound and grip first, then add power.
The FL5 is the sixth-generation Civic Type R, sold in the US from the 2023 model year. Its K20C1 engine responds well to bolt-ons and tuning, and the chassis is good enough that tires, brakes and suspension make as much difference on a back road or track day as extra horsepower. This guide covers each upgrade in the order most owners should do them, what each one actually changes and which parts are worth the money.
FL5 Mods at a Glance
| Order | Mod | What it improves | Best for |
|---|---|---|---|
| 1 | Intake and turbo inlet pipe | Cooler intake air, throttle response, turbo sound | Every FL5 |
| 2 | ECU tune | The biggest power and torque gain per dollar | Owners chasing performance |
| 3 | Cat-back exhaust | Sound, some weight savings | Owners who want more character |
| 4 | Springs or coilovers | Stance, body control, track handling | Daily drivers (springs), track cars (coilovers) |
| 5 | Wheels and tires | Grip, unsprung weight, tire cost | Track day and autocross drivers |
| 6 | Big brake kit | Fade resistance and pedal feel on track | Regular track use |
| 7 | Aero | High-speed stability and downforce | Track cars |
| 8 | Clutch and turbo | Holding and making big power | Built cars only |
1. Intake and Turbo Inlet Pipe
The factory FL5 intake sits behind the radiator, where it can pull in hot air after a few hard pulls or a track session. A sealed aftermarket intake fixes that first. The Eventuri carbon fiber intake for the FL5 Civic Type R uses a sealed prepreg carbon airbox and Eventuri's Venturi housing. Eventuri reports dyno gains of about 14 hp and 15 lb-ft, plus sharper throttle response and more induction sound.
The next restriction is the factory turbo inlet tube. Eventuri's FL5 carbon charge pipe grows from about 78 mm to 88 mm toward the turbo, which Eventuri rates at more than 32% extra cross-sectional area. That matters more once the car is tuned and the turbo is asked to move more air. If you're deciding between the two, our guide on FL5 Eventuri intake vs turbo tube explains which should come first.
2. ECU Tune
A flash tune is where the FL5 makes its biggest jump in power. The tune raises boost and adjusts timing and fueling targets within what the stock turbo and engine can handle. Most FL5 tuning platforms flash through the OBD port and let you return to the factory calibration.
Things to know before you tune:
- Fuel matters. Tuned maps are written for a specific octane. Use the fuel your map calls for, every time.
- Bolt-ons need matching maps. An intake, turbo inlet pipe or downpipe changes airflow, so load a map built for your exact parts.
- Emissions and warranty. Check your state's rules and understand that tuned engines can complicate powertrain warranty claims.
AutoTalent doesn't sell an FL5 tune right now, so use an established Honda tuning platform and a tuner with real FL5 experience.
3. Cat-Back Exhaust
The stock FL5 exhaust is quiet and refined. A cat-back replaces everything after the catalytic converters and is the easiest way to give the car more character. It won't add much power on its own, but it will change how the car sounds on every drive. Three good options for the FL5:
- Milltek. The Milltek valved FL5 cat-back with GT-115 tips uses 3.00-inch, 304L stainless pipework. Milltek offers non-resonated and Road+ versions, valved and non-valved, and several tip styles, so you can choose volume and tone.
- Borla ATAK. Borla's 2.75-inch ATAK cat-back for the 2023+ Type R keeps the factory exhaust valve, uses T-304 stainless and keeps the triple-tip layout, with a 4.5-inch center tip and two 4-inch outer tips. ATAK is Borla's most aggressive sound level.
- Fi Exhaust. Fi's T304 stainless valvetronic cat-back lets you switch between a quiet setting and an open race sound with the factory drive modes or Fi's optional remote and app.
Not sure what a cat-back replaces? Our cat-back vs axle-back guide explains the difference.
4. Lowering Springs or Coilovers
The FL5 sits higher than most owners like, and its adaptive dampers are good on the street. That gives you two clear paths:
- Lowering springs keep the factory adaptive dampers. Swift Spec-R springs for the FL5 drop the car about 1.0 inch front and rear with 6.3 kg/mm front and 7.5 kg/mm rear rates, and Eibach offers its Sportline kit for 2023-2024 Type R models. Springs are the right choice for most daily-driven cars.
- Coilovers make sense if you track the car. The Öhlins Road & Track coilover system, which fits both the FK8 and FL5, uses Öhlins' Dual Flow Valve dampers with height adjustment and 20-plus click damping adjustment, monotube construction and inverted front struts. Because the FL5's factory dampers are electronically adaptive, ask us which cancellation solution your car needs before you order coilovers.
After lowering, get a proper alignment. Front camber and toe settings affect how the FL5 turns in and how evenly its front tires wear.
5. Wheels and Tires
The FL5 comes on 19-inch wheels with low-profile tires. Many track-focused owners switch to a lighter forged wheel, often an 18-inch size, for lower unsprung weight, a taller tire sidewall and cheaper replacement tires. Titan 7 makes forged FL5 fitments such as the T-D6, T-P5 and T-C5 in 18x9.5 and 19x9.5 with a 5x120 bolt pattern and 45 mm offset.
Two things to check before buying: tire size and brake clearance. If you plan to add a big brake kit later, confirm that the wheel clears the calipers before you buy either part.
6. Big Brake Kit
The FL5's factory Brembo front brakes are strong on the street. On track, repeated hard stops build heat, and that's when fluid, pads and rotors start to fade. Start with high-temperature brake fluid and track pads. If you track the car often, a big brake kit adds rotor mass and caliper stiffness.
The Brembo GT front big brake kit for the FL5 uses radial-mount 6-piston cast monobloc calipers and 380x32 mm two-piece floating slotted rotors, and it comes with high-performance pads, braided hoses, adapters and hardware. Brembo's GT-S, GT-R and Race kits go further. Larger rotors need wheel clearance, so check your wheels first.
7. Aero
Aero only pays off at speed, so it belongs near the end of a street build and near the top of a time-attack build. APR Performance makes a full FL5 program, including the GTC-300 adjustable wing (67-inch span, 13-inch standing height, carbon fiber reinforced polymer with 6061 billet aluminum pedestals), front bumper canards and side rocker extensions. If you add rear downforce, balance it at the front, too.
8. Clutch and Turbo Upgrades
Big power needs a drivetrain to match. Once a tuned FL5 starts to slip its clutch, an upgraded clutch kit, such as a cerametallic Stage 2 design, is the fix. Confirm FL5 fitment before you order, because many Type R clutch kits were developed for the FK8. The final step is a larger turbo. Pure Turbos' Pure550 upgrade keeps the factory turbo housings and supports 500+ wheel horsepower with the right supporting mods. Its listing states that it's legal only for competition vehicles under California law, so it's for dedicated track cars, not road cars.
Sample FL5 Build Paths
| Goal | Mods |
|---|---|
| Daily driver | Intake, cat-back exhaust, lowering springs, alignment |
| Fast street car | Intake, turbo inlet pipe, tune, cat-back exhaust, springs, alignment |
| Track day car | Brake fluid and pads, coilovers, lighter wheels and track tires, big brake kit, intake and tune |
| Time attack | Everything above, plus wing, front aero, clutch and supporting cooling |
Ready to shop? Browse every part we stock for your car in our Honda Civic Type R FL5 parts collection.
FL5 Mods FAQ
What is the first mod to do on an FL5?
A sealed intake is the most common first mod. It lowers intake temperatures, sharpens throttle response and adds turbo sound, and it supports a tune later.
How much horsepower does the FL5 Civic Type R have?
The US-market 2023+ Civic Type R makes 315 hp and 310 lb-ft from its 2.0L turbocharged four-cylinder engine.
Do FL5 mods void the warranty?
Not automatically. In the US, a dealer generally has to show that a modification caused a failure before denying a related claim. Tuning can still complicate engine and transmission claims.
Are FK8 parts compatible with the FL5?
Some are and many aren't. The FL5 shares its engine family with the FK8, but the intake, exhaust and body parts are different. Only buy parts that list the FL5 or 2023+ Civic Type R.
Should I lower my FL5 with springs or coilovers?
Springs suit most daily-driven cars because they keep the adaptive dampers. Coilovers are better for regular track use, where adjustable damping and ride height help.
Is a big brake kit necessary on an FL5?
Not for the street. For frequent track days, start with fluid and pads. Add a big brake kit if you still get fade.