Ram 1500 5.7 Hemi Intake Manifold Upgrade

The Ram 1500 equipped with the 5.7L Hemi engine is a popular platform for performance upgrades. One of the most common and effective modifications is an intake manifold upgrade. While the stock manifold is adequate for everyday driving, aftermarket options can significantly improve airflow, resulting in increased horsepower and torque, particularly in the mid to upper RPM ranges. This article will delve into the details of upgrading the intake manifold on a 5.7L Hemi Ram 1500, covering everything from choosing the right manifold to installation procedures and potential issues.

Understanding the Intake Manifold

Before diving into the upgrade process, it's essential to understand the function of the intake manifold. Simply put, the intake manifold's job is to distribute the air/fuel mixture evenly to each cylinder in the engine. The design of the manifold plays a crucial role in determining engine performance. Factors like runner length, plenum volume, and overall flow capacity all influence how efficiently the engine can breathe.

The stock 5.7L Hemi intake manifold is a composite (plastic) design. While lightweight and cost-effective, it often becomes a bottleneck in modified engines. The long, relatively narrow runners are optimized for low-end torque and fuel economy, but they restrict airflow at higher RPMs. This is where aftermarket intake manifolds come into play.

Choosing the Right Intake Manifold

Several aftermarket intake manifold options are available for the 5.7L Hemi. Each design offers different performance characteristics and is best suited for specific applications. Here's a breakdown of common types:

Short Runner Intake Manifolds: These manifolds feature shorter and wider runners, which improve airflow at higher RPMs. They generally sacrifice some low-end torque in favor of increased horsepower at the top end. These are often preferred for racing applications or trucks used primarily for high-speed performance. Expect improved throttle response and a more aggressive power band.
Long Runner Intake Manifolds: While less common than short runner designs in the aftermarket, some manufacturers offer slightly enhanced long runner manifolds. These aim to improve upon the stock manifold without sacrificing low-end torque. They may offer a slight increase in both horsepower and torque across the RPM range.
Variable Length Intake Manifolds: Some advanced designs incorporate a variable runner length system, often using electronically controlled valves. This allows the manifold to optimize runner length for both low-end torque and high-end horsepower. These are typically more expensive and complex to install.

When selecting an intake manifold, consider your intended use for the truck. Are you looking for maximum horsepower on the track, or a balanced improvement for street driving and towing? Research different brands and read reviews to determine which manifold best suits your needs. Manufacturers like Edelbrock, Holley, and MSD are popular choices.

Also, confirm that the manifold is compatible with your year and model of Ram 1500. Some manifolds may require modifications or additional components for proper fitment. Check the manifold's flange type to ensure it mates correctly with your cylinder heads.

Installation Process: A Step-by-Step Guide

Installing an intake manifold is a relatively straightforward process for experienced DIYers. However, it's crucial to follow the instructions carefully and take your time. Before starting, disconnect the negative battery terminal to prevent any electrical issues.

Step 1: Preparation and Disassembly

Begin by removing any components that obstruct access to the intake manifold. This typically includes the air intake system, throttle body, fuel rails, fuel injectors, and any vacuum lines or sensors connected to the manifold. Be sure to label and photograph all connections before disconnecting them to ensure proper reassembly. Drain the coolant system slightly as some coolant passages run through the intake manifold. Disconnecting the fuel lines requires extra care to avoid spills and fire hazards.

Step 2: Removing the Old Intake Manifold

Once the surrounding components are removed, you can access the intake manifold bolts. These bolts are usually torqued to a specific value, so use a torque wrench to loosen them gradually in a star pattern. This helps to prevent warping the manifold or cylinder heads. Once all the bolts are removed, carefully lift the intake manifold off the engine. Be mindful of any remaining vacuum lines or sensors that may still be attached.

Important: Before removing the old manifold, thoroughly clean the area around the intake ports on the cylinder heads. This will prevent any debris from falling into the engine during removal. Stuff clean rags into the intake ports after the manifold is removed.

Step 3: Preparing the New Intake Manifold

Before installing the new intake manifold, inspect it for any defects or damage. Install any necessary fittings, sensors, or vacuum ports onto the new manifold. Many aftermarket manifolds require you to transfer certain sensors or vacuum fittings from the old manifold. This is also a good time to install new intake manifold gaskets. Ensure the gaskets are properly aligned with the intake ports on both the manifold and the cylinder heads. Apply a thin bead of RTV sealant at the corners where the intake manifold meets the cylinder heads and block to prevent leaks.

Step 4: Installing the New Intake Manifold

Carefully lower the new intake manifold onto the engine, ensuring that the gaskets are properly seated. Install the intake manifold bolts and torque them to the manufacturer's specifications in a star pattern. This ensures even pressure distribution and prevents leaks. Refer to the service manual or the intake manifold manufacturer's instructions for the correct torque values.

Step 5: Reassembly and Final Checks

Reconnect all the components that were removed in Step 1, including the throttle body, fuel rails, fuel injectors, vacuum lines, and sensors. Double-check all connections to ensure they are secure. Refill the coolant system and prime the fuel system. Reconnect the negative battery terminal.

Step 6: Start-Up and Testing

Start the engine and let it idle for a few minutes. Check for any leaks around the intake manifold, fuel rails, or coolant passages. Monitor the engine temperature to ensure it doesn't overheat. Use a scan tool to check for any diagnostic trouble codes (DTCs) related to the intake manifold or associated sensors. Finally, take the truck for a test drive to evaluate the performance improvements.

Potential Issues and Troubleshooting

While the intake manifold upgrade is generally straightforward, some potential issues can arise:

Vacuum Leaks: Vacuum leaks are a common problem after installing an intake manifold. These leaks can cause rough idling, poor performance, and diagnostic trouble codes. Use a vacuum gauge or smoke tester to locate and repair any leaks.
Fuel Leaks: Fuel leaks are a serious safety hazard. Ensure that all fuel line connections are secure and leak-free. Replace any damaged fuel lines or fittings.
Coolant Leaks: Coolant leaks can cause overheating and engine damage. Ensure that all coolant passages are properly sealed. Replace any damaged coolant hoses or fittings.
Incorrect Sensor Readings: Incorrect sensor readings can cause poor performance and diagnostic trouble codes. Ensure that all sensors are properly connected and functioning correctly. Replace any faulty sensors.
Tuning Issues: After installing an aftermarket intake manifold, the engine's air/fuel ratio may need to be adjusted to optimize performance. This can be accomplished by reflashing the engine's computer (ECU) with a custom tune. A custom tune ensures the engine receives the correct amount of fuel to match the increased airflow. Failure to tune the engine can result in poor performance or even engine damage.

Tip: Investing in a tuning device and a custom tune from a reputable tuner is highly recommended to maximize the benefits of the intake manifold upgrade and ensure optimal engine performance and longevity.

Conclusion

Upgrading the intake manifold on a Ram 1500 5.7L Hemi can be a rewarding modification, providing noticeable improvements in horsepower and torque. By carefully selecting the right manifold, following the installation instructions diligently, and addressing any potential issues, you can unlock the full potential of your engine and enjoy a more engaging driving experience. Remember to always prioritize safety and consult with a qualified mechanic or tuner if you have any questions or concerns. Proper tuning after installation is critical for optimal performance and engine health.