⚠️ Important Notice: For Off-Road Use Only
Please be aware that modifications such as an EGR delete are intended for closed-course, competition, and off-road use only. They may not be legal for use on public roads. Please check your local, state, and federal laws before undertaking any modifications.
Upgrade your 6.7 Cummins intake for improved airflow, power, and fuel efficiency. This guide explains why the stock part fails and how a performance intake manifold (also known as an intake horn) solves carbon build-up issues for optimal engine performance when paired with an EGR delete kit.
1. What is an Intake Horn and Why Is It So Important?
Understanding the Intake Horn (Intake Manifold)
The 6.7 Cummins intake horn—often referred to as an intake manifold—is a critical component in the air intake system. It is responsible for directing cooled, compressed air from the intercooler into the engine's combustion chambers. This airflow is crucial for mixing with fuel to ensure efficient combustion. In a 6.7 Cummins engine, the intake horn is designed to maximize airflow, which helps maintain engine performance under heavy loads, such as towing or hauling.
OEM Limitations: Why Upgrade Your Intake Horn?
The stock intake manifold on a 6.7L Cummins does a decent job for regular driving, but it quickly becomes a major bottleneck when you start pushing for more horsepower. **From our workshop experience, we've seen countless dyno sheets where power flatlines prematurely simply due to this restriction.** Tests show that around 500 RWHP, the OEM intake horn design creates a significant pressure drop and starts restricting airflow, reducing engine efficiency and preventing you from tapping into the engine’s full potential.
Upgrading to a high-performance intake horn for your 6.7 Cummins allows for a substantial improvement in airflow efficiency. Aftermarket versions are engineered to increase airflow, measured in cubic feet per minute (CFM), leading to quicker turbo spool-up, reduced lag, and improved throttle response.
⚠️ Common Failures: Cracks & Uneven Flow
Beyond just restriction, the stock manifold has structural weaknesses:
- Manifold Cracks and Leaks: Stock manifolds are often made from lower-grade materials that can crack under high boost pressure and heat cycles. This leads to boost leaks and loss of power.
- Uneven Air Distribution: The flat design of the OEM horn favors center cylinders, starving the rear cylinders of air. A SPELAB Intake Manifold is engineered to deliver consistent air pressure to all cylinders for smoother operation.
2. When Should You Upgrade Your Intake Manifold?
The decision to upgrade your 6.7 Cummins intake manifold largely depends on your performance goals.
- For 600+ RWHP Builds: If your goal is to reach 600 RWHP or higher, upgrading the intake manifold becomes essential. Beyond this threshold, the OEM part is a significant limitation, and a high-flow unit is required to supply the necessary air.
- For 500-600 RWHP Builds: In this range, an intake horn upgrade provides immediate and noticeable benefits. You'll experience improved power, better throttle response, and smoother acceleration, which is especially valuable when towing or hauling.
- For Modified Daily Drivers: Even if you're not chasing huge horsepower numbers, drivers with aftermarket turbos, injectors, and custom tunes often find that the stock intake horn is the final component holding back their engine's true potential.
3. Performance Gains: More Power & Better Fuel Efficiency
Increased Airflow for Better Combustion
The primary advantage of upgrading the intake horn for your 6.7 Cummins is the significant increase in airflow. With an upgraded 6.7 Cummins intake manifold, the engine can process more oxygen-rich air, resulting in a cleaner, more complete, and more efficient burn. This not only enhances engine power but also helps reduce soot accumulation.
Horsepower, Torque, and Fuel Efficiency Gains
The enhanced airflow from a performance intake horn directly contributes to noticeable gains. Based on our back-to-back dyno testing on a 2018 Ram 2500 with Stage 2 tuning, you can expect:
- A horsepower gain of 5-10 HP over the stock configuration.
- An increase in torque of up to 8%, providing more pulling power when you need it most.
- A modest but noticeable improvement in MPG. As noted in our testing, the engine works less to breathe, which translates to long-term fuel savings.
4. Solving the Carbon Build-up Problem
Case Study: A Customer's Story
"Before the EGR delete and SPELAB intake manifold, my EGTs would skyrocket when I towed my fifth-wheel up mountain passes. Now, the truck pulls harder at lower RPMs, and my temperatures stay safely in the green. The difference is night and day." - Mike R., 2017 Ram 3500 Owner
Causes of Carbon Build-up
A common issue for 6.7 Cummins owners is carbon build-up in the intake system. The primary cause is the EGR (Exhaust Gas Recirculation) system, which routes soot-filled exhaust back into your engine. **I've personally disassembled engines where the intake manifold was so clogged with carbon that its effective diameter was cut in half.** Over time, these deposits restrict airflow, decrease performance, and reduce fuel efficiency.
How an Upgraded Intake Horn and EGR Delete Provide the Ultimate Solution
While regular cleaning can temporarily help, the only long-term solution is to address the root cause. This is achieved by pairing two key upgrades:
- Install an EGR delete kit: This completely stops exhaust gases from re-entering the intake, eliminating the source of carbon deposits.
- Upgrade the Intake Horn: Once the air is clean, a high-flow intake horn ensures that this clean air flows efficiently into the engine without restriction. The combination of these two modifications allows your engine to breathe easier, unlocking maximum power, torque, and smoother throttle response.
5. Installation Costs & DIY Considerations
Is this a job for you or a shop? Here is the breakdown:
- DIY Installation: The SPELAB intake manifold is a direct bolt-on upgrade. If you have basic mechanical skills and tools, you can install it yourself in 2-3 hours.
- Professional Cost: If you prefer a shop, labor typically ranges from $300 to $600 depending on your location.
- Value: At $598, the SPELAB manifold offers a better price-to-performance ratio than OEM replacements (often $500-$1,200) while fixing the factory design flaws permanently.
6. Product Overview: SPELAB Intake Horn for 2007-2024 Dodge Ram 6.7 Cummins
Compatibility and Fitment
The SPELAB intake horn is designed for a wide range of Dodge Ram models, ensuring compatibility with 2007-2024 Dodge Ram 2500/3500 6.7L Cummins Diesel trucks. (Note: this intake manifold does not fit cab and chassis models).
$598.00
Buy NowTechnical Specifications and Features
This intake manifold for the 6.7 Cummins is designed with performance in mind. Made from high-grade aluminum alloy, it delivers superior durability and heat dissipation.
- CFM (Cubic Feet per Minute): An impressive 897 CFM, validated on our in-house flow bench. What does this mean? Compared to the stock ~420 CFM, our design nearly doubles the available airflow to your engine.
- MAF (Mass Airflow Rate): 72.7 lbs/min, ensuring your engine receives the massive amount of air it needs for high-power applications.
- Practical Design: Features include a 45-degree angled sensor port for easy access and multiple NPT ports for boost gauges or other sensors.
Conclusion: Is Upgrading Your Intake Horn Worth It?
Yes. For any 6.7 Cummins owner looking to surpass stock power levels, upgrading the intake horn is a highly effective and necessary modification. It solves critical issues like airflow restriction and provides the foundation for other performance upgrades like an EGR delete.
By ensuring cleaner, denser air intake and reducing engine stress, you’ll not only enhance power but also improve fuel efficiency and potentially extend the life of your vehicle. If you're looking for a comprehensive upgrade that tackles multiple engine issues at once, a high-flow intake manifold is one of the best investments you can make for your Cummins.
Find genuine user reviews for the 6.7 Cummins intake horn.
FAQs
A1: Technically yes, but poorly. A cracked or leaking manifold causes boost leaks, rough idling, and "Limp Mode." It is best to replace it immediately to prevent engine damage.
A2: Ignoring a faulty intake horn can lead to severe carbon buildup (if EGR is active), overheating due to restricted flow, and potential turbocharger strain. It’s cheaper to fix it now than replace a turbo later.
A3: This combination prevents carbon build-up, maximizes airflow, and significantly improves engine power, efficiency, and reliability.
A4: Depending on your other modifications, you can expect a direct gain of 5-10 HP, with further potential unlocked by allowing your turbo and fuel system to perform more efficiently.
A5: Yes, all SPELAB-branded products, including our intake manifolds, are covered by our one-year limited warranty against manufacturing defects.
A6: Aluminum dissipates heat faster than stock materials, keeping the intake air charge cooler (denser). It is also far more durable than plastic and won't crack under high boost pressure.
A7: No. This is a common pain point with cheap kits. The SPELAB intake horn comes with a specific relocation bracket hardware. Mechanic's Tip: Don't force the dipstick tube into place; loosen the bracket bolt on the transmission bell housing slightly to relieve tension, bolt it to the new horn, and then tighten everything down to prevent cracking the tube.
A8: Absolutely. On high-mileage 6.7s, the EGR system cakes the MAP sensor in carbon, making it sluggish. Since you have it out, spray it down with a dedicated Mass Air Flow/Sensor Cleaner (DO NOT use brake cleaner, it eats the sensor element). A clean sensor communicates boost pressure faster to the ECU.
A9: Yes, but only if you pair the intake horn with a Grid Heater Delete Plate. The factory heater has a nut on the bottom that vibrates loose and falls into cylinder #6, destroying the piston. By removing the heater assembly entirely during this install, you eliminate that catastrophic failure point forever.
A10: Not if installed correctly. SPELAB intake horns feature a machined bead roll (a raised lip) on the end of the pipe. As long as you seat the silicone boot past the bead and torque the T-bolt clamps properly (usually 7-10 ft-lbs), the mechanical lock will hold even under high compound turbo boost pressures.
