If you’re thinking about upgrading your car’s intake, you probably want to know which ones actually add horsepower. Aftermarket intakes promise better airflow and more power, but not all of them deliver the same results.
The truth is, most aftermarket intakes add a modest 5 to 15 horsepower. Some high-performance options do offer more noticeable gains, but it’s not always dramatic.
Choosing the right intake matters. It affects not just power, but also engine sound and efficiency.
Testing different models on a dyno shows that some intakes perform better than others. Some barely improve anything at all.
This article breaks down how these intakes work and what you can expect in terms of power. You’ll see results from real tests and get a sense of which intake might be worth your investment.
Key Takeaways
- Most intakes add between 5 and 15 horsepower.
- Engine sound and airflow can improve with the right intake.
- Dyno tests reveal which intakes deliver real power gains.
How Aftermarket Intakes Impact Horsepower
Upgrading your intake system changes how air flows into your engine. This can affect horsepower.
Different parts—like the airbox, intake tubing, and intake pipe—all play roles. How well the system keeps air cool also matters for both power and efficiency.
Airflow and Engine Performance
Your engine needs a steady, smooth flow of air to burn fuel well. Aftermarket intakes often increase airflow by using wider tubes or less restrictive filters compared to OEM parts.
This means more air reaches the engine, which can help it produce more horsepower. However, the gain is usually modest, typically between 5 to 15 horsepower depending on your vehicle and engine size.
Forced induction engines, like those with turbochargers, might see better airflow benefits. Still, the quality of airflow is as important as quantity—it needs to be consistent and free of turbulence.
Key Components: Airbox, Intake Tubing, and Intake Pipe
The airbox houses the air filter and protects the engine from dirt. It also helps control airflow temperature.
Aftermarket airboxes may be larger or made from materials that reduce heat transfer. Intake tubing connects the airbox to the throttle body.
Aftermarket tubes are often wider and smoother inside, which reduces air resistance. The intake pipe, part of this tubing, affects how quickly and easily air can reach the engine.
By upgrading these parts, you can improve how much air flows and how cool it stays. This helps your engine run better and may increase horsepower slightly.
Heat Soak and Efficiency Factors
Heat soak happens when the intake system absorbs heat from the engine bay. Warmer air contains less oxygen, which lowers combustion efficiency and horsepower.
Aftermarket intakes with insulated or specially designed airboxes help reduce heat soak. Positioning the intake to pull air from outside the engine compartment also keeps things cooler.
Efficiency depends on surface area and material. Larger filters with more surface area let in more air without being restrictive.
Using materials that resist heat transfer helps keep airflow cooler and the engine running well.
Types of Aftermarket Intakes Tested
You’ll find several types of aftermarket intake systems designed to improve airflow and boost horsepower. These systems vary mainly in where they draw air from and how they filter it.
Understanding the differences will help you pick the right setup for your needs and vehicle.
Cold Air Intakes vs. Short Ram Intakes
Cold air intakes (CAI) are built to pull cooler air from outside the engine compartment. Cooler air is denser and can improve combustion, leading to better horsepower and torque.
CAIs usually have longer tubes and enclosed airboxes to shield the air filter from engine heat. Short ram intakes, on the other hand, draw air from inside the engine bay.
They have shorter tubes and a more direct airflow path, which can improve throttle response. However, since the air inside the engine bay is warmer, short ram intakes can sometimes reduce performance under heavy use.
You should weigh the climate and your driving style when choosing between these.
Cone Filter and Larger Diameter Intake Options
Many aftermarket intakes use cone-shaped air filters made from cotton or synthetic materials. These filters have more surface area than stock filters, allowing more air to flow through with less restriction.
A larger diameter intake tube can also help by letting more air into the engine. The wider tubing, combined with cone filters, typically increases airflow, which may improve horsepower by a few points.
Some designs can create more intake noise or risk sucking in hot air if not properly placed. It’s a tradeoff worth considering.
Comparison to OEM and Aftermarket Systems
OEM (Original Equipment Manufacturer) intakes are designed for balance between cost, noise control, and emissions. They often use smaller tubes and air filters that limit airflow but keep the engine quieter and cleaner.
Aftermarket systems replace OEM parts with larger tubes, high-flow filters, and sometimes better heat shielding. These changes tend to increase horsepower and throttle response, but may produce more intake noise.
Some aftermarket intakes also make maintenance easier, with reusable filters you can clean instead of replace.
Key Differences at a Glance:
| Feature | OEM Intake | Aftermarket Intake |
|---|---|---|
| Airflow | Moderate | Increased |
| Air Filter Type | Paper/Stock | Cone / High-flow |
| Intake Tube Diameter | Smaller | Larger |
| Engine Heat Shielding | Standard | Often improved |
| Noise Level | Quieter | Louder |
| Maintenance | Replace filters | Reusable & cleanable |
Dyno Testing and Real-World Power Gains
When testing aftermarket intakes, you need clear data on wheel horsepower (whp) and torque. Measuring these with a dyno gives real-world results.
Understanding how sensors and fueling work with your intake also affects power gains.
Wheel Horsepower and Torque Results
Wheel horsepower (whp) is the power measured at the wheels after losses from the drivetrain. It gives you a more realistic idea of how much power your engine actually delivers.
Aftermarket intakes can add whp, but gains tend to be modest—often between 5 to 15 whp on most cars. Torque changes show how the intake affects engine pulling power, which helps in acceleration.
Reliable dyno testing includes multiple runs to confirm consistent power gains. You should expect some variation, but look for improvements in both whp and torque that repeat over several tests.
Measuring Performance Gains Accurately
Dyno tests should be done without changing other engine parts or tuning. That way, you see the intake’s true effect.
Running the same setup multiple times on a consistent dyno surface gives more reliable results. Use a chassis dyno or wheel-based dynamometer for accuracy.
Some intakes claim big horsepower gains, but real dyno results are often smaller. Look for data showing actual whp and torque increases, not just estimated numbers.
That’s the kind of info that helps you decide if the intake is worth the money, based on real, verified performance improvements.
Sensor and Fueling Considerations
Your car’s mass airflow (MAF) sensor keeps track of how much air is coming in. This helps the engine figure out how much fuel to use.
When you swap in an aftermarket intake, the way air moves can change quite a bit. Sometimes, that throws off the sensor’s readings.
If the sensor isn’t reading right, your fueling gets messed up. You might even lose power, which is the opposite of what you want.
Some setups need you to tweak or reprogram the engine’s fueling to match the new intake. Skipping this step can make the upgrade feel pointless.
