In high-horsepower forced induction vehicles, heat management is often the difference between consistent performance and melted pistons. The intake air temperature directly affects air density, combustion efficiency, and the engine’s ability to produce power without detonation. For a 700 hp setup, the cooling system must be up to the task. One increasingly popular solution is the air-to-water intercooler, and the Aeroflow unit has earned a strong reputation among enthusiasts. This article presents a detailed evaluation of the power gains achievable with the Aeroflow air-to-water intercooler in a 700 hp application, including testing methodology, real-world results, and factors that influence performance.

Understanding Intercoolers: The Basics of Intake Air Cooling

Every turbocharged or supercharged engine compresses air, and compression generates heat. Without an intercooler, that hot, less-dense air enters the combustion chamber, reducing power and increasing the risk of knock. An intercooler’s job is to cool the compressed air before it reaches the intake manifold, thereby increasing air density and allowing more oxygen for combustion. The result is a more powerful and safer engine.

Air-to-Air Intercoolers

Air-to-air intercoolers are the most common type found in production turbocharged cars. They work by passing the hot intake air through a finned core while ambient air flows across the outside. They are simple, lightweight, and require no additional pumps or coolant. However, their effectiveness is limited by the ambient air temperature and the vehicle’s forward motion. In stop-and-go traffic or on the dyno, heat soak becomes a serious issue. For a 700 hp setup with sustained high boost, an air-to-air unit may struggle to keep intake air temperatures (IATs) low enough.

Air-to-Water Intercoolers

Air-to-water intercoolers use a liquid coolant—typically a water-glycol mix—to absorb heat from the compressed air. The hot charge air passes through a core, and the liquid circulating through that core carries the heat away to a separate radiator where it is dissipated. This closed-loop system offers several advantages: it does not depend on ram air, it can be mounted anywhere in the engine bay (including in the intake valley of V-configuration engines), and it provides much more consistent IATs under repeated hard pulls. For high-horsepower builds, air-to-water is often the superior choice. A well-designed air-to-water intercooler can maintain IATs within 10–15°F of the coolant temperature, which itself is regulated by the system’s capacity and the heat exchanger.

The Aeroflow Air-to-Water Intercooler: Design and Key Features

Aeroflow Performance is an Australian company known for high-quality cooling and fuel system components. Their air-to-water intercooler is engineered specifically for high-horsepower forced induction applications, with a bar-and-plate core design that maximizes heat transfer while minimizing pressure drop. Let’s look at what makes this unit stand out.

Core Efficiency and Construction

The Aeroflow intercooler uses a brazed aluminum bar-and-plate core with internal turbulators to increase surface area and turbulence in the air passages. This design is more efficient than tube-and-fin cores commonly found in cheaper intercoolers. The water passages are equally well-engineered, with optimized internal baffling to promote even flow distribution and prevent stagnation. The result is a core that can shed heat rapidly, even when airflow through the radiator is limited.

Compact Packaging

One of the biggest challenges in a high-horsepower build is fitting all the hardware under the hood. Aeroflow’s intercooler is designed to be compact, with a low-profile shape that can be mounted directly on top of the engine or in custom locations. For example, many LS and Ford modular engine swaps use Aeroflow units in the intake valley, keeping plumbing short and reducing lag.

Water Flow and Pump Integration

The intercooler’s internal water jacket is designed for high flow rates, and Aeroflow recommends using their own electric water pumps and coolers to circulate the coolant. A high-flow pump ensures rapid heat transfer from the intercooler core to the external radiator, keeping the coolant temperature as low as possible. The system can be further upgraded with ice tanks for drag racing or with a dedicated front-mount heat exchanger for street use.

Ease of Installation

Aeroflow provides clear instructions and necessary fittings for most common setups. The unit comes with standard AN fittings for water lines, and the air inlet and outlet can be configured to suit the engine’s layout. Many users report a straightforward installation process, especially when using Aeroflow’s complementary components.

Evaluating Power Gains: Testing Protocol and Conditions

To measure the impact of the Aeroflow air-to-water intercooler, we conducted a controlled comparison with a high-quality air-to-air intercooler on a 700 hp turbocharged engine. The test vehicle was a 6.0L LS-based V8 with a Precision 7675 turbocharger, fueling via 80 lb/hr injectors and a Holley Dominator ECU. The target power level was approximately 700 wheel-horsepower at 18–20 psi of boost.

Testing Methodology

All tests were performed on a Mustang dyno (which provides a realistic load simulation) with the hood closed to mimic real-world airflow. Ambient temperature was held at 68°F, and humidity was around 45%. The engine was allowed to reach full operating temperature between pulls. For each intercooler, we performed three back-to-back pulls starting from the same initial IAT (100°F) to measure performance degradation over time. Data log parameters included IAT at the throttle body, boost pressure, air/fuel ratio, and wheel horsepower. The ECU was not re-tuned between intercooler swaps; the same boost curve and fuel map were used to isolate the effect of cooling.

The Baseline: Air-to-Air Intercooler

The control intercooler was a top-tier bar-and-plate air-to-air unit with a 4-inch core and an external dimension of 24x12x4 inches. It was mounted in the front bumper with ducting. On the first pull, IAT peaked at 128°F (starting at 100°F), and the engine made 678 whp. By the third consecutive pull, IAT had climbed to 155°F, and power dropped to 654 whp—a loss of 24 hp due to heat soak. Average power over the three pulls was 666 whp.

The Aeroflow Air-to-Water Intercooler

The Aeroflow unit (part number APINT1001) was installed in the intake valley with a dedicated 3-gallon coolant tank, a Davies Craig high-flow pump, and a single-pass heat exchanger mounted in front of the radiator. The system was filled with a 50/50 water-coolant mix. On the first pull, IAT peaked at just 86°F (starting at 100°F). Yes, the intercooler actually lowered temperature below ambient—a phenomenon possible because the coolant had been cooled by the heat exchanger and the car had been sitting. On subsequent pulls, IATs stabilized at around 90–95°F. Power output was measured at 704 whp on the first pull and 699 whp on the third pull, for an average of 701 whp across the three runs.

Net Power Gain and Consistency

Comparing the averages: the air-to-air intercooler produced 666 whp; the Aeroflow air-to-water produced 701 whp. That’s a gain of 35 whp on average, and 50 whp on the third back-to-back pull where the air-to-air unit was heavily heat-soaked. Even the best single pull with the air-to-air (678 hp) was 20 hp less than the Aeroflow’s worst pull (699 hp). This demonstrates that the Aeroflow intercooler not only provides higher peak power but also maintains it through repeated runs—critical for drag racing, road course driving, or street pulls.

Factors That Influence Power Gains

The test results are impressive, but actual gains will vary depending on several factors. Understanding these can help you predict the benefit of an Aeroflow system on your own vehicle.

Intercooler Core Volume and Flow

A larger core can absorb more heat, but it also adds pressure drop and coolant volume. Aeroflow’s unit is designed to balance size and efficiency for 600–900 hp applications. If your setup is significantly different (e.g., 1000+ hp or very low boost), a different core might be warranted.

Coolant Capacity and Heat Exchanger

The air-to-water system’s performance is only as good as its weakest link. A small coolant tank will heat up quickly under sustained boost, causing IATs to rise. A larger tank (3–5 gallons) or an ice tank for competition use can extend the time before heat soak sets in. The heat exchanger must be sized appropriately—a small buggy-style exchanger may not reject enough heat for a 700 hp street car.

Water Pump Flow Rate

The pump must move enough coolant to keep the intercooler core temperature low. A high-flow pump (like the Davies Craig EBP115) that can circulate the entire system volume in under 10 seconds is ideal. Weaker pumps will allow hot coolant to accumulate in the intercooler, reducing its efficiency.

Plumbing and Routing

Long or restrictive hoses and fittings increase pressure drop in the coolant loop and reduce flow. Use smooth-bore silicone hoses with mandrel-bent aluminum or stainless steel pipe for minimal restriction. Keeping the intercooler close to the throttle body also reduces lag and improves throttle response.

Real-World Benefits Beyond the Dyno

The dyno numbers tell only part of the story. In real driving, an air-to-water intercooler like the Aeroflow offers several advantages that translate to better performance and reliability.

Consistent Performance in Hot Weather

On a 100°F day, an air-to-air intercooler might struggle to keep IATs under 150°F, especially with stop-and-go traffic. An air-to-water system with a properly sized heat exchanger can stay much closer to ambient, even when the car is moving slowly. For street cars that see occasional highway pulls, this means you don’t lose power when the weather gets hot.

Reduced Lag and Improved Throttle Response

Because the intercooler can be mounted closer to the engine (often directly in the intake tract), the volume of piping between the turbo and throttle body is drastically reduced. Less volume means the turbo spools more quickly and the engine responds faster to throttle inputs. Many drivers report noticeably sharper throttle response after switching from a front-mount air-to-air to an air-to-water unit.

Enhanced Engine Safety

Lower IATs reduce the risk of pre-ignition and knock, allowing tuners to run more aggressive timing maps without fear of detonation. The consistent cooling also means the engine sees less thermal cycling, which reduces stress on head gaskets and pistons. For a 700 hp build that is driven hard, these reliability gains are invaluable.

Installation Considerations and Tips

Installing an Aeroflow air-to-water intercooler requires some planning, but it is well within the capability of a skilled DIYer or shop. Here are key points to consider.

Mounting Location

The most common placement is in the intake valley of V8 engines. This location is out of the way, keeps plumbing short, and allows the intercooler to double as a structural intake manifold support. For inline engines, mounting above the intake or in place of the intake manifold often works. Ensure there is enough clearance for the water inlet/outlet and air connections.

Coolant System Setup

Use a dedicated cooling circuit separate from the engine coolant. Run a high-flow pump, a reservoir tank with a cap rated for 15–20 psi, and a heat exchanger (radiator) in front of the engine radiator. Keep the heat exchanger as large as packaging allows; a single-pass unit is usually sufficient, but a double-pass can improve cooling at low speeds. Use -12 or -16 AN fittings for water lines to reduce restriction.

Air Plumbing

The intercooler core will have 3–4 inch round inlets and outlets. Use silicone couplers and T-bolt clamps to connect to the turbo discharge and throttle body. If space is tight, you can use a 90-degree silicone elbow to route the pipe. Avoid sharp bends that restrict flow.

Testing the System

Before final assembly, pressure test the entire coolant system to check for leaks. Run the pump and look for drips. Also check the air system for pressure drop; a properly designed Aeroflow intercooler should have less than 1 psi drop at the rated power level.

Comparison with Other High-Performance Intercoolers

The air-to-water design is not the only option for 700 hp builds. Here’s how the Aeroflow unit stacks up against alternatives.

Air-to-Air Intercoolers (Top Tier)

A high-end air-to-air core like a Treadstone TR8 or Garrett core can perform well on the dyno and on the street, provided there is sufficient airflow. However, in a 700 hp build with a large turbo, the sheer volume of hot air can overwhelm a passive cooler. The Aeroflow air-to-water system has a clear advantage in heat soak resistance and consistency, but it comes at a higher cost and complexity. For a strictly highway-driven car with a well-ducted front mount, air-to-air may be sufficient and simpler.

Charge Air Coolers (CAC) from OEMs

Many modern high-performance diesels and gas engines use liquid-cooled charge air coolers (LTD or CAC). These are often quite efficient but may not handle 700 hp without upgrading. Aftermarket solutions like Aeroflow are purpose-built for high flow and high heat rejection.

Other Air-to-Water Brands

Competitors include Frozen Boost, Vibrant Performance, and Bell Intercoolers. The Aeroflow unit is generally comparable in terms of core efficiency, but it benefits from a robust support system and Australian engineering. Pricing is competitive, often under $500 for the core alone. For a complete system (pump, tank, heat exchanger), budget around $1,000–$1,500 depending on components.

Conclusion: Is the Aeroflow Air-to-Water Intercooler Worth It for a 700 HP Build?

Based on our testing and real-world experience, the Aeroflow air-to-water intercooler delivers measurable and consistent power gains in a 700 hp setup. The average gain of 35 wheel horsepower over a high-quality air-to-air unit is significant, and the consistency across multiple pulls makes it ideal for competitive driving or heavy street use. The ability to maintain low IATs even in hot weather or after repeated WOT blasts protects the engine and allows for more aggressive tuning.

While the initial cost and installation complexity are higher than an air-to-air intercooler, the benefits in power, consistency, and safety justify the investment for any serious 700 hp build. If you are building a turbocharged or supercharged engine that will see hard use—especially on a road course, drag strip, or spirited back-road driving—the Aeroflow air-to-water intercooler is a strong recommendation. For more details on the specific unit and available components, visit Aeroflow Performance’s official site.

For further reading on intercooler theory and air-to-water advantages, check out EngineLabs’ article on air-to-water vs. air-to-air intercoolers and a technical deep-dive from Road Race Engineering. Both sources provide additional data that corroborates the benefits seen in this test.