Airflow plays a crucial role in diesel engine efficiency and overall performance. For 6.7 Cummins owners, two key components significantly impact how air moves into the engine: the grid heater and the intake horn. While the grid heater is designed for cold-weather starts, it can sometimes restrict airflow. Meanwhile, upgrading the intake horn can help optimize combustion, improve throttle response, and boost power.
In this article, we’ll explore the role of the Cummins grid heater, the benefits of modifying or deleting it, and how upgrading the 6.7 Cummins intake horn can enhance engine performance.
Understanding the Cummins Grid Heater
The grid heater is an electric heating element inside the Cummins diesel engine’s intake manifold. Its primary purpose is to warm the incoming air before it enters the combustion chamber, ensuring better cold starts in freezing temperatures.
How the Grid Heater Works
- The grid heater is activated when you turn the key in cold weather.
- It heats the air passing through the intake manifold, making combustion easier.
- This process helps reduce white smoke and misfires during cold starts.
Potential Issues with the Grid Heater
While the grid heater is beneficial for winter driving, it has some downsides that lead many Cummins owners to consider modifications or deletions:
- Restricted Airflow – The grid heater element and mounting bolts create turbulence, disrupting smooth airflow into the intake manifold.
- Bolt Failure Risks – The bolts securing the grid heater have been known to break and fall into the engine, potentially causing catastrophic failure.
- Carbon & Soot Buildup – Over time, soot accumulates on the grid heater, further restricting air passage and decreasing engine efficiency.
- Not Always Necessary – In warmer climates, the grid heater is rarely needed, making its removal a viable option.
Should You Delete the Grid Heater?
Many performance enthusiasts and truck owners install a grid heater delete kit to eliminate airflow restrictions and potential failure points. By replacing the grid heater with a smooth passageway, more air can reach the cylinders with less turbulence, increasing power and efficiency.
6.7 Cummins Intake Horn: The Key to Better Airflow
The intake horn is a critical component in the air intake system of a 6.7 Cummins engine. It connects the intercooler to the intake manifold, directing compressed air into the engine.
Why Upgrade the Intake Horn?
The factory-installed intake horn is designed to meet emissions and noise regulations rather than optimize performance. Many aftermarket intake horns offer a larger diameter, smoother bends, and fewer restrictions, allowing more air to enter the engine.
Key Benefits of an Upgraded Intake Horn:
Increased Air Volume – A high-flow intake horn reduces bottlenecks, allowing more air to reach the combustion chambers.
Better Throttle Response – The engine responds quicker when accelerating with improved airflow.
More Horsepower and Torque – Improved air delivery means a more efficient burn, translating into more power.
Lower Exhaust Gas Temperatures (EGTs) – More air means cooler combustion, reducing strain on the engine during towing or heavy loads.
Cummins Grid Heater vs. Intake Horn: Which Upgrade Should You Prioritize?
The BThegrid heater and intake horn play a role in engine airflow, but if you decide which upgrade to prioritize first, consider your driving needs.
| Upgrade | Best For | Performance Gains |
| Grid Heater Delete | Performance-focused builds, warm climates, avoiding potential engine failures | Increased airflow, reduced restriction, improved reliability |
| High-Flow Intake Horn | All driving conditions, improved engine response, better turbo performance | Faster air delivery, improved power, lower EGTs |
For maximum efficiency, many Cummins owners install both upgrades, eliminating restrictions while ensuring the smoothest possible air intake.
Installation Guide: Grid Heater Delete & Intake Horn Upgrade
Tools & Parts Needed:
Ratchet & Socket Set
Torque Wrench
Grid Heater Delete Kit (Optional)
Performance Intake Horn
Gaskets & Sealant
Installation Steps:
- Disconnect the Batteries – Always start by ensuring no power is running to the engine.
- Remove the Stock Intake Horn – Unbolt the factory intake horn and set it aside.
- Access the Grid Heater – If removing it, locate it inside the intake manifold.
- Unbolt and Remove the Grid Heater (Optional) – Carefully extract the heater and replace it with a delete plate.
- Install the New Intake Horn – Attach the upgraded horn and ensure all seals and gaskets are correctly fitted.
- Reconnect the Battery and test for Leaks. Start the engine and check for air leaks before taking it on a test drive.
Note: If you delete the grid heater, your truck’s ECU may throw a check engine light. Tuning may be required to prevent warning codes.
Who Should Consider These Upgrades?
Truck Owners in Warmer Climates: If you rarely need cold-start assistance, removing the grid heater will not affect operation.
Performance Enthusiasts – Both upgrades are beneficial if you want maximum airflow and efficiency.
Towing & Hauling Drivers – Lower EGTs and better throttle response make these mods ideal for towing heavy loads.
Turbocharged Builds – A smoother intake pathway helps turbos spool faster, improving boost delivery.
Final Thoughts: Are These Upgrades Worth It?
For 6.7 Cummins owners looking to improve airflow, efficiency, and reliability, upgrading the intake horn and removing the grid heater are two excellent modifications.
A grid heater eliminates potential failures while improving air movement inside the intake manifold. Meanwhile, an upgraded intake horn ensures a smoother, more efficient path for air entering the engine, leading to better throttle response, more power, and lower EGTs.
If you’re serious about performance, these two simple yet effective upgrades can make a noticeable difference in your Cummins diesel truck’s driving experience.