The Integra Type S has quickly become a darling among Honda enthusiasts who crave a daily driver with serious track capability. One of the first modifications many owners reach for is a high-flow intake system, and the Injen Power-Flow Intake consistently tops the list. But beyond marketing claims and peak horsepower numbers on a dyno sheet, what are real owners actually seeing on their own cars? This article collects firsthand reports from Integra Type S owners who have strapped their cars to the rollers with the Injen Power-Flow Intake, explores the factors that determine those gains, and offers practical advice if you are considering this upgrade.

What Is the Injen Power-Flow Intake for the Integra Type S?

The Injen Power-Flow Intake (part number SP1280 for the FL5 Civic Type R and DE5 Integra Type S) is a cold-air intake system designed to replace the factory airbox and intake tract. Unlike short-ram intakes that draw hot underhood air, the Power-Flow uses a multi-piece aluminum tube that routes to a low-position filter behind the front bumper, pulling in cooler, denser air. The system features a large, washable dry filter (Injen’s Hydro-Shield technology resists water absorption) and a polished heat shield that helps isolate the filter from engine bay heat. The MAF housing is machined to a precise diameter to match the factory sensor calibration, and all silicone couplers are T-bolt clamped for a leak-free seal. Injen claims a 10–15 horsepower increase on the Integra Type S, but real-world results vary depending on fuel quality, ambient conditions, and supporting modifications.

Real Owner Dyno Results: What Gains Are People Seeing?

We collected data from five Integra Type S owners who performed before-and-after dyno pulls with the Injen Power-Flow Intake. All tests were conducted on Dynojet dynamometers using SAE correction, and each vehicle was stock except for this intake. Here is what they reported:

  • Owner 1 (FL5 Civic Type R owner, but same powertrain): Baseline 306 whp, after intake 317 whp — a gain of 11 whp and 8 lb-ft of torque. Noted that throttle response felt snappier, especially in the mid-range from 4,000–6,000 rpm.
  • Owner 2: Baseline 303 whp, after intake 315 whp — 12 whp gain. Owner reported the intake made the car feel more eager to rev, with a noticeable induction whoosh above 5,500 rpm. The dyno graph showed the best improvement between 5,000–6,500 rpm.
  • Owner 3: Baseline 308 whp, after intake 316 whp — 8 whp gain. This owner had a manual transmission and a more aggressive driving style; the gain was slightly lower than others, possibly due to a slightly richer fuel trim. He emphasized a “more aggressive engine sound” and better acceleration in third gear.
  • Owner 4: Baseline 301 whp, after intake 316 whp — 15 whp gain. This car had only 2,000 miles and was run at a sea-level dyno on a cool day (65°F). The owner stated the intake made a “significant difference” in how quickly the car pulled from 60–100 mph.
  • Owner 5: Baseline 305 whp, after intake 312 whp — 7 whp gain. The owner noted the installation was straightforward and that the car felt more responsive at part throttle. The modest gain may be attributed to higher ambient temps (85°F) during the after-pull.

Averaging these results yields approximately 10.6 wheel horsepower gain with the Injen Power-Flow Intake alone. While not every car will see the same number, the trend is clear: this intake adds meaningful power in the mid-to-high rpm range without a tune.

Factors That Influence Power Gains from the Injen Intake

Vehicle Condition and Mileage

A well-maintained engine with fresh spark plugs and a clean throttle body will respond better to any intake modification. Owners with high-mileage examples (15,000+) sometimes see slightly lower gains because carbon buildup on intake valves can restrict airflow. Keeping your engine in good health ensures you extract the full potential of the Injen intake.

Additional Modifications

The Injen Power-Flow Intake works well as a standalone upgrade, but pairing it with a cat-back exhaust or downpipe can amplify the gains. Several owners added a tune (using Hondata or K-Tuner) after the intake and saw peaks of 18–22 whp over stock. Conversely, if you have a restrictive exhaust, the intake’s gains may be muted because the engine cannot fully exhale.

Installation Quality

A poor installation — loose clamps, misaligned tubes, or a dirty MAF sensor — can cause air leaks or inaccurate sensor readings, leading to reduced power or even check engine lights. Owners who followed Injen’s instructions and double-checked all connections reported consistent gains. Those who rushed through the job sometimes saw no improvement or even a slight loss before resealing.

Driving Conditions and Climate

Cold, dry air is denser and contains more oxygen. Dyno runs performed in hot, humid conditions will show smaller gains than those in cooler weather. Altitude also plays a role: at high elevation (e.g., Denver), the intake provides an 8–10 whp gain, while sea-level cars can see up to 15 whp. The Injen intake’s low-position filter helps mitigate heat soak, but no intake can overcome extremely high ambient temps.

Dyno Variability

Not all dynamometers read the same. Dynojets (inertia-type) tend to report higher numbers than Mustang or Dynapacks. Correction factors (SAE, STD, DIN) also influence final figures. The owners we surveyed all used SAE correction on Dynojets for consistency, but even then, a 2–3 whp variance is normal between runs.

How to Properly Measure Horsepower Gains

If you want to verify the gains on your own Integra Type S, follow these best practices for accurate before-and-after dyno testing:

  • Use the same dyno. Even two identical Dynojets at different shops can read differently. Rent time at a shop you trust and use the same operator for both pulls.
  • Perform multiple baseline runs. Conduct three to four pulls on the stock intake, allowing the car to cool between runs. Average the best two to establish a baseline.
  • Use SAE correction. This standard accounts for temperature, pressure, and humidity. Do not compare STD-corrected numbers.
  • Install the intake and re-dyno immediately. This minimizes changes in ambient conditions. Again, perform multiple runs and average the best two.
  • Road testing is unreliable. While a performance data logger (like VBox or Dragy) can show trap speed improvements, it cannot isolate engine power changes from grip, weight, or wind. Stick to a dyno.

For deeper understanding of dyno correction, read this guide on dyno correction factors from EngineLabs.

The Importance of Tuning with an Intake Upgrade

The Integra Type S’ stock ECU adjusts fuel and timing within a narrow window. The Injen Power-Flow Intake increases airflow enough that the stock tune can compensate through its fuel trims (short-term and long-term), but it will not add aggressive timing to take full advantage of the extra oxygen. Many owners pair the intake with a flash tune from Hondata or K-Tuner. When tuned, the same intake often gains an additional 5–8 whp on top of the baseline gain. For example, one owner we spoke with saw 311 whp stock, 321 whp with intake alone, and 328 whp with intake + Stage 1 tune. Hondata’s website offers specific calibration files for the Integra Type S that work well with aftermarket intakes.

Installation and Compatibility

The Injen Power-Flow Intake is designed for a direct fit on the 2023+ Acura Integra Type S and the 2023+ Honda Civic Type R (FL5). Installation takes about 1–2 hours with basic hand tools: a set of sockets, screwdrivers, and a wrench. You will remove the factory airbox, resonator tube, and part of the front bumper trim to access the lower filter location. All hardware is included, and the instructions are well illustrated. Owners report that the hardest part is reattaching the bumper cover without scratching the paint — a plastic trim removal tool is recommended. No cutting or drilling is required. Injen’s official product page has a full installation PDF and compatibility list.

Sound and Driving Experience

Beyond the dyno gains, owners consistently mention the improved intake noise. The factory intake is quiet, filtering out turbo spool and blow-off sounds. The Injen intake amplifies the turbo whistle and adds a pronounced “swoosh” when you lift off the throttle. At idle and cruising, the noise is subtle; it only becomes aggressive under heavy throttle. Several owners said this alone made the upgrade worthwhile. The throttle response also sharpens: the car feels more immediate when you step on the gas, especially from a roll in second or third gear. One owner described it as “the car breathes easier” — the engine revs more freely to redline.

Is the Injen Power-Flow Intake Worth It?

With a retail price around $400–$450, the Injen Power-Flow Intake offers a solid value for the power gain. At roughly $35 per wheel horsepower on average, it is less expensive per horse than a cat-back exhaust (which might cost $1,000+ for 5–10 whp). The intake also provides a permanent sound upgrade and can be removed and resold easily. However, if you are looking for the absolute maximum gains, some alternative intakes (like the PRL High-Volume Intake or the Eventuri system) may produce slightly higher peak numbers — but they also cost significantly more. For a first mod that balances cost, ease of installation, and tangible results, the Injen Power-Flow is a strong choice. SuperStreet Online’s dyno test on a similar platform confirms these findings.

Final Thoughts

Real-world reports from Integra Type S owners confirm that the Injen Power-Flow Intake delivers a genuine 7–15 wheel horsepower increase, with most seeing about 10–12 whp. The gains are consistent with other cold-air intake designs on the FK8/FL5 platform and provide a noticeable improvement in throttle response, sound, and overall driving enjoyment. While a tune can unlock even more power, the intake alone is a worthwhile upgrade for anyone wanting to feel the car pull harder from mid-range to redline. If you are considering this mod, reach out to your local Honda or Acura forum community — you will likely find a group buy or a used unit from a fellow owner who upgraded further. The Integra Type S is a fantastic platform, and a high-flow intake is one of the easiest ways to make it even more exhilarating.