Honda Civic FL5 Type R Dyno Results: WHP Delta Per Mod Guide

The FL5 Honda Civic Type R (2023–present) is the 11th-generation iteration of Honda’s flagship performance Civic. Powered by an updated version of the K20C1, the same 2.0-liter turbocharged four-cylinder found in the FK8, the FL5 benefits from a revised Turbocharger with a new compressor wheel, a larger intercooler, a redesigned intake system, and updated ECU calibration. Honda rates the FL5 at 315 hp at 6,500 rpm and 310 lb-ft at 2,600–4,000 rpm at the crank, increases of 9 hp and 15 lb-ft over the FK8.

The FL5’s ECU is more sophisticated than the FK8’s, using a Bosch MG1 architecture that required Hondata to develop a new jailbreak procedure before FlashPro support became available. The engine retains the same closed-deck block, forged internals, and direct-injection fuel system as the FK8, but the turbocharger spools 300–400 rpm earlier and delivers 20–40 lb-ft more torque from 2,000–3,500 rpm. This article documents dyno-verified output at every stage: OEM stock, Hondata Stage 1, intake and tune, and the per-modification delta for each upgrade.

FL5 Type R Dyno Results at a Glance

There is no single “stock WHP” number for the FL5 Type R. Different dynos, weather, elevation, and correction factors produce different results. The ranges below represent observed results from published dyno tests and community data.

These are observed ranges from published dyno results, not guaranteed results for every car. The FL5’s ECU is unusually sensitive to ambient conditions, and dyno results can vary by 15–25 whp between different dynos and weather conditions.

Stock Output: How Much WHP Does the FL5 Really Make?

Hondata was the first to put a stock FL5 on a dyno, publishing results in November 2022. On their in-house dyno, the FL5 produced 327 whp at 6,411 rpm and 359 wtq at 3,419 rpm on 91 octane fuel. This compared to 316 whp and 334 wtq from their 2017 FK8 on the same dyno — a gain of 11 whp and 25 wtq. The torque curve improvement was more significant than the peak numbers suggest: the FL5 delivered 20–40 lb-ft more torque from 2,000–3,500 rpm, with the turbo reaching peak boost approximately 300–400 rpm earlier than the FK8. (Source: Hondata, 2023 Civic Type R Dyno Results, Nov 2022)

On a Dynojet 224xLC, Two Step Performance recorded 306 whp and 333 wtq on a stock FL5 with a PRL drop-in air filter (the only modification) on 93 octane. The lower absolute number compared to Hondata’s dyno reflects dyno-to-dyno variation rather than a discrepancy in the car’s output. A CivicXI owner on a Dynojet recorded 307 whp and 327 wtq on 93 octane. On a Mustang Dyno (known for reading lower), a stock FL5 produced 270 whp and 312 wtq. On a DynaPack hub dyno, the same car produced 321 whp and 350 wtq. (Sources: TSP, FL5 performance guide, 2023; CivicXI.com, FL5 Dynojet and Mustang/DynaPack baselines)

The community consensus is that a healthy FL5 on a Dynojet in moderate weather produces 305–310 whp and 325–335 wtq on 93 octane, and approximately 320–330 whp on Hondata’s dyno. The FL5’s torque curve is its defining advantage over the FK8: peak torque arrives by approximately 3,000–3,400 rpm and holds flat through 5,000 rpm before tapering, whereas the FK8’s torque curve peaked later and dropped off more sharply.

Hondata FlashPro Stage 1: The Best Power-per-Dollar Mod

The Hondata FlashPro for the FL5 became available after Hondata developed a jailbreak for the Bosch MG1 ECU. The FlashPro provides access to boost targets, ignition timing, cam phasing, fuel tables, throttle response, and the ability to raise the rev limiter and remove the speed limiter. Hondata ships the FlashPro with pre-loaded 91 octane and 93 octane base calibrations.

Hondata claims the 93 octane base calibration produces 370 hp AT the crank, a gain of 45 hp and 50 lb-ft over the factory rating. On their dyno, this translates to approximately 370 whp (their dyno reads close to crank figures). The 93 octane calibration adds 2–3 degrees of timing over stock and increases boost targets. (Source: Hondata, FlashPro FL5 product page)

Two Step Performance tested their own TSP Stage 1 calibration for the FL5 on a Dynojet 224xLC. The test car had a PRL drop-in air filter, TSP high-efficiency downpipe, PRL intercooler, and Milltek front-pipe-back exhaust. The factory tune on this car produced 306 whp and 333 wtq. The Hondata 93 base MAP produced 321 whp and 368 wtq. The TSP Stage 1 calibration produced 361 whp and 383 wtq — a gain of 55 whp and 50 wtq over the factory calibration on the same dyno. (Source: TSP, FL5 Civic Type R Performance Guide, 2023)

The TSP Stage 1 tune is designed for stock or basic bolt-on FL5s and does not require the downpipe, intercooler, or exhaust that were on the test car. The power gains are primarily from the calibration itself, with the bolt-on parts contributing additional headroom. The tune includes full-throttle shifting, a 4,000 rpm launch control limit, disabled rev hang, and a comfort mode that retains factory torque request mapping.

The typical Stage 1 FL5 on 93 octane produces approximately 355–370 whp on a Dynojet, depending on the specific calibration and ambient conditions. The torque curve shifts upward by approximately 40–50 wtq across the midrange, with peak torque arriving at approximately 3,000–3,500 rpm and holding stronger to redline.

Hondata OTS Tune vs Custom Tune

A custom tune does not automatically mean huge peak horsepower gains over an OTS calibration. The advantage of a custom tune often lies in smoother power delivery, safer fueling, better boost control, improved midrange response, and adaptation to the specific car and fuel quality.

In controlled testing, a custom calibration can deliver significantly better results than an OTS map. The custom tune can better account for the specific fuel quality, actual airflow, boost behavior, knock feedback, and the individual car’s characteristics. However, OTS maps from reputable tuners like Hondata and TSP are already well-developed and deliver excellent results for most owners.

Intake + Tune: The Per-Mod Delta

Hondata conducted a systematic per-modification dyno test on the FL5 to isolate the contribution of each upgrade. The testing was performed on their in-house dyno with controlled conditions: sea level, 75 degrees Fahrenheit ambient, two fans on high continuously, two minutes between runs, and engine Coolant temperature stabilized at 182–183 degrees Fahrenheit. The power drop from the first run to the stabilized baseline was 20 hp, which Hondata noted as an important variable: simply allowing the car to cool between installations can show a 20 hp gain regardless of the part’s actual contribution. (Source: Hondata, Technical Information FL5 basic bolt-ons)

Exhaust (simulated open pipe): Hondata simulated the best-case exhaust upgrade by running an open pipe at the flange, which has a 2-inch diameter at the disconnection point. The result was an 8–11 HP gain across most of the rev range. This represents the ceiling for a cat-back exhaust upgrade; real-world exhaust systems with mufflers and resonators will produce slightly less. (Source: Hondata, FL5 bolt-on technical information)

Eventuri intake: The Eventuri intake for the FL5 is a complete redesign from the FK8 version, using a carbon fiber housing and a venturi stack design. Hondata tested it and recorded 18–25 hp gains across the rev range. This is an unusually large gain for an intake on a modern turbocharged Honda and reflects the FL5’s factory intake system being more restrictive than the FK8’s. The carbon fiber construction reduces heat conduction into the intake air, which contributes to the gain. (Source: Hondata, FL5 bolt-on technical information)

PRL intake: The PRL intake for the FL5 added 3–10 hp across the rev range, a smaller gain than the Eventuri. Hondata attributed the difference to the Eventuri’s carbon fiber construction providing better heat isolation. The PRL intake is still a worthwhile upgrade, particularly when combined with a tune, but the Eventuri delivers substantially more peak power. (Source: Hondata, FL5 bolt-on technical information)

PRL intercooler: The PRL front-mount intercooler added 10 hp at the top of the rev range. Intercoolers have more volume and take more time to fill with air, which can reduce throttle response as boost takes longer to reach the engine. Hondata noted that a Honda race team reverted their race car intercoolers back to stock for this reason. On the street, the intercooler’s benefit is most apparent on hot days and during sustained boost, where it prevents the charge air temperature from rising and triggering knock retard. (Source: Hondata, FL5 bolt-on technical information)

Hondata reflash: The reflash was the single largest gainer in Hondata’s testing, adding more power than any individual bolt-on part and at a lower cost. The reflash increases boost targets, optimizes ignition timing for higher octane fuel, and adjusts cam phasing for the specific hardware configuration. Hondata’s 93 octane base calibration adds 45 hp and 50 lb-ft at the crank, which translates to approximately 40–50 whp depending on the dyno. (Source: Hondata, FL5 bolt-on technical information; FlashPro product page)

Hondata’s per-mod testing was conducted on their in-house dyno. Gains are approximate and will vary based on ambient conditions, fuel quality, and the specific combination of parts.

Combined Bolt-Ons + Tune: The FBO Picture

While Hondata’s per-mod testing isolated individual components, the real-world FBO FL5 combines multiple upgrades with a custom or OTS tune. TSP’s test car with a PRL drop-in filter, TSP downpipe, PRL intercooler, and Milltek exhaust on the TSP Stage 1 tune produced 361 whp and 383 wtq on a Dynojet. This represents a gain of 55 whp and 50 wtq over the factory calibration on the same dyno. The car did not have an aftermarket intake (only a drop-in filter), suggesting that adding an Eventuri or PRL intake would push the car past 370–380 whp on the same tune. (Source: TSP, FL5 performance guide, 2023)

Based on the per-mod deltas, a fully bolted FL5 with an Eventuri intake, downpipe, front pipe, intercooler, cat-back exhaust, and a custom tune on 93 octane would be expected to produce approximately 380–400 whp on a Dynojet. The stock turbocharger on the FL5 is the same MHI TD04 unit used in the FK8, and its flow ceiling is approximately 390–400 whp on pump gas. Beyond that point, a turbo upgrade is required.

The FL5’s stock fuel system (direct injection with a high-pressure Fuel Pump) can support approximately 400–420 whp on pump gas before injector duty cycle becomes a limitation. The stock clutch handles FBO power levels on most cars, though higher-mileage cars or cars driven aggressively at the track may experience slip.

The Warm-Up Problem: Why Dyno Numbers Can Change by 20 HP

Hondata explicitly noted that the difference between a warm car and a fully warmed-up car can be approximately 20 hp. This is a critical methodology point that explains why different tests of the same car can produce different results.

Why your FL5 can make 20 WHP less on the same dyno: intake temperature, coolant temperature, charge-air temperature, heat soak, ECU adaptation, and cooling fan performance all affect the final number. A car that has been properly cooled between runs will produce significantly more power than one that is heat-soaked.

The practical implication: when comparing dyno results, always ask about the test conditions. A 20 hp difference between two runs of the same car is not necessarily a modification gain — it may simply be a temperature difference.

The FL5 Turbo: Why Torque Gains Can Be Bigger Than Peak WHP

Early tuning results show that increasing boost can produce a significant torque gain but a smaller peak WHP gain at high rpm, because the stock turbo has limited high-rpm flow capacity. The FL5’s revised compressor wheel improves low-end response, but the turbo’s high-rpm performance is similar to the FK8’s.

This means that +40–60 lb-ft of torque can feel significantly more dramatic than +10–20 WHP peak. The car pulls harder in the midrange, even if the peak horsepower number doesn’t jump as dramatically as the torque figure.

Cost per WHP: The FL5 Value Proposition

Hondata FlashPro Stage 1 ($795–895): 40–55 whp gain on 93 octane. Cost per whp: approximately $16–20. This is the single best value in the FL5 modification catalog and one of the best power-per-dollar ratios of any modern Honda.

Eventuri intake + FlashPro ($1,800–2,200): Intake ($1,000–1,200) plus FlashPro ($795–895). Total gain of approximately 60–75 whp. Cost per whp: approximately $28–32.

FBO + custom tune ($4,000–5,500): FlashPro ($795–895), downpipe ($400–700), front pipe ($200–350), intercooler ($600–800), intake ($400–1,200), cat-back exhaust ($600–1,200), custom dyno tune ($400–600). Total gain of approximately 75–95 whp. Cost per whp: approximately $45–60.

The FlashPro alone delivers more power gain per dollar than any individual bolt-on part. The intake and intercooler add power but at a higher cost per whp, and their primary value is in supporting the tune’s full potential rather than in their standalone gains.

What Makes the Biggest Difference?

1. Tune: The biggest gain per dollar. The FlashPro alone delivers 40–55 whp for under $900.

2. Intake (Eventuri): The best bolt-on gain, delivering 18–25 hp on its own.

3. Intercooler: More consistency and thermal stability, with 10 hp at the top end.

4. Downpipe: Adds 15–25 hp with a tune, but less effective without calibration.

5. Catback exhaust: Often affects sound, weight, and flow characteristics more than peak horsepower.

The ECU Jailbreak: The FL5’s Hidden Cost

One critical difference between the FK8 and FL5 is the ECU. The FL5’s Bosch MG1 ECU is locked from the factory and requires physical removal and shipping to Hondata for jailbreak before FlashPro can be installed. This adds time and cost to the tuning process.

The jailbreak process involves removing the ECU from the car, sending it to Hondata (or an authorized dealer), and having the security unlocked. The cost is included in the FlashPro purchase, but the downtime is a consideration for owners who need the car daily.

Quick Reference — FL5 Dyno Results

☐ Stock FL5 WHP on Dynojet: 305–310 / on Hondata dyno: 327 / on Mustang: ~270

☐ Hondata Stage 1 (93 oct): 355–370 WHP / 370–385 WTQ on Dynojet

☐ TSP Stage 1 (93 oct, w/ bolt-ons): 361 WHP / 383 WTQ (Dynojet)

☐ Eventuri intake gain: +18 to +25 hp across the rev range

☐ PRL intake gain: +3 to +10 hp

☐ Cat-back exhaust gain: +8 to +11 hp (best case)

☐ Intercooler gain: +10 hp at top end — consistency benefit is more important

☐ Downpipe gain: +15 to +25 hp with a tune

☐ FBO estimated: 380–400 WHP on 93 octane

☐ Stock turbo ceiling: ~390–400 WHP on pump gas

☐ Stock fuel system limit: ~400–420 WHP on pump gas

☐ Stage 1 tune is the best power-per-dollar mod — 40–55 WHP for under $900

☐ The FlashPro alone delivers more power per dollar than any bolt-on

☐ ECU jailbreak is required before FlashPro installation — the FL5’s Bosch MG1 ECU must be physically removed and sent to Hondata

☐ The FL5’s torque curve is its biggest advantage over the FK8 — 20–40 lb-ft more torque from 2,000–3,500 rpm

☐ Dyno numbers are not directly comparable across different dynos and conditions

☐ A 20 hp difference can occur on the same dyno just from temperature differences

FAQ — FL5 Type R Dyno Results