Fleece Performance Solves the 6.7L Cummins Grid Heater Problem

In the 6.7 Cummins world, the grid heater bolt has become a well-established concern and a heavy topic of discussion. While there are several options on the market to address this failure-point, Fleece Performance Engineering really made us take a pause and look at the solution in a different light. The task of eliminating the bolt is just a small part of the equation. The beauty is everything else that supports that mission and what shines with this particular solution.

A common set of goals that Fleece has when planning a new product is to be able to design parts that cover the widest year ranges with fewer SKUs. Designing the kits to be complete with all parts needed for the installation of the product and to solve problems for all levels of clientele, from the distributor to the dealer to the end users alike, are also top priorities. So, let’s unpack this a little further and review what we like about this product.

Year Range Coverage

This product covers the entire 2007.5-2024 year range, including cab and chassis trucks in one SKU. This means that distributors only need to stock one part. Therefore, they can easily keep inventory levels high for excellent availability for their customers. The end users and self-installers can confidently order a part that is readily available with no year range confusion.

No Special Fuel Line Required

With other options on the market, you are required to use a specialty high-pressure fuel line for the #1 injector. The downfall of this is that if you are to develop a leak or the line gets a pinhole, which does happen, you need to go directly to the manufacturer for a replacement. To an enthusiast, that may not seem like a big deal, but to a shop or a vehicle owner who is unfamiliar with what parts are included in that installation, it can cause unforeseen issues. We have seen people who need to replace the line and unknowingly order a stock replacement line and end up in a frenzy. Did they order the wrong one? Is it the parts store guy again?! And where in the world do I find this on a Saturday when I need to get back to work on Monday? This can be a major pain point that may not be considered until you are in the middle of it.

Heating Element Options

Based upon your climate, you have multiple options available to you. With the standard configuration, you have one heater coil installed in the intake horn that will get the job done. In cold-weather climates, you are able to install a second heater, which will help during extreme cold days to get you started and idling smoothly in a hurry. Another beauty of this product is that if you’re in a pinch and experience heater failure, a new coil could be sourced locally, again making future service easy. It is recommended that you do source the replacement from Fleece directly to ensure that it meets the proper specifications, though. As a rule of thumb, Fleece suggests that a single heater is effective above 0°F, and for climates that get below 0°F, a second heater is highly recommended.

Heater Cable

A new heater cable comes with the kit, which allows for more routing options and is easier to install rather than trying to reuse the existing cable. The heater cable has a protective boot on it to cover the connection point to the heater coil, which is left exposed with other kits. This is something that we add in addition to installs with other brands of intake horns, and it is nice to see that it is included here.

It’s All in the Box

When it comes to ease of installation, Fleece sets you up for success. This kit comes with everything you need—seals, gaskets, hardware, and harnesses. When you are ready for installation, there is no unexpected part you need that delays you. It’s all there ready to go.

To gather some more insight on the project, we spoke with John Benshoof, Director of Product Development at Fleece, who walked us through its development and shared some of his stories and standout moments along the way.

When discussing some of the reasons why they decided to develop this product, John simply stated, “We listen to the customers. They tell us what they want; we just have to listen.” The most prominent customer concern in this case is the grid heater bolt breaking off and being consumed by the engine and causing catastrophic engine failure. A majority of customers are satisfied with the power and capabilities of their trucks, but the thought of such an obscure issue causing such a massive failure has created a wave of unnerved owners seeking a solution.

Included in the solution to this primary concern, Fleece set out to make a plug-and-play design that is easy to install with no cutting or grinding needed. No proprietary or specialty parts are required, and staying within a factory fitment window keeps things simple for the end user.

Once the project was determined and original designs were drafted, testing and validation were required next to prove the product’s effectiveness. Within the testing and validation, there were five critical steps that we had discussed.

Flow Bench Testing

A flow bench is used to measure the amount of airflow through a component. This measurement will show the full potential of the component and more easily prove the concept before continuing with the next steps of design.

On the 6.7 Cummins, the cylinder head itself is a major flow restriction; therefore, total flow (CMF) through the intake horn isn’t a huge focus. The main goal is to meet or exceed the flow of the stock intake.

Dyno Testing

The next step is to get the product installed on an engine to see how it compares when integrated into the entire system. The desired goal is to meet or exceed the performance of the factory intake when testing horsepower/torque numbers as well as stay within the required emissions guidelines. Accomplishing the desired results here means the product is ready for the next step.

Cold Chamber Testing

Although the factory intake heater is the source of concern, it does play an extremely important role in the system when it comes to cold starts and meeting emissions requirements. And it does its job very well. To remove it, there has to be an alternative put into place. This is where things got fun and interesting for the Fleece crew. To properly test and validate the heater’s performance and capabilities, they had to find a way to work in a controlled environment. The solution to this? Put the entire truck in a cold chamber that is set at -35°C (-31°F) and put some intakes to the test. They started the testing with the factory intake to gather baseline data before moving to other variations. Through the testing, they found that the factory grid heater is extremely effective for cold starts primarily because the grid is directly in the airflow path. After several design iterations, they landed on a coil-style heating element that, when used as a pair located close to the intake opening in the cylinder head, will get you the results you need. The added benefit to this style is that it can be locally sourced if there’s ever a need for replacement.

Road Test/Real World Testing

A road test to verify operation in real life and across vast variables is of utmost importance. Sometimes even the simplest changes made to a component can result in hidden issues that are not exposed until you get enough run time on an engine. It may be operating the engine in just the right condition or having the truck go through enough regeneration cycles that an issue is identified. This process takes time and miles to verify.

Full Capability Testing

The word on the street is that Fleece has some plans to showcase this intake in various settings to really show what it is made of.

After talking with John about this project, his enthusiasm and pride in what the Fleece team has created are clear. We asked about aspects of the project that he enjoyed the most; he responded, “Understanding how we could make the product fit on everything.” Over the 16-year span there have been changes to components such as IAT sensors, MAP sensors, fuel lines, and rails, as well as their locations. So, coming to the end with one product that does it all is an impressive accomplishment. John also stated, “At my core, I love to solve problems,” and that the “testing and validation process” on the dyno and the cold chamber were some of his most memorable moments.

Along with our excitement for the release, we were able to see the industry reaction during PRI, which led us to question John about what he was most proud of about the project. Fittingly, he replied, “I think the customer response on this one. It’s like a validation that all of the thoughts and goals and hard work that the team put into it and the vision of the company all came together. And it hit.”

Installation

We had the opportunity to perform an installation of one of these intake kits on our 4th gen Ram. Once we received the kit, we had it sent to our powdercoat shop to have it matched to the other engine bay parts. At this time all Fleece intakes will come raw, but the finish on them is great to receive powdercoating if that is desired.

The unboxing alone shows how well thought-out this product was down to the finest details in the packaging and layout. With each part in its own color-coded place, it is easy to identify what you have and that there is nothing missing—no guesswork. The next step in the color coding is how it ties into the installation instructions. The colors are used to clearly point to where they will be used and are backed by great pictures and descriptions.

Installation went as planned. Everything that was needed was there ready to go. For me, one of the most welcomed points in the installation came when it was time to set the intake horn in place. If you have installed other intakes, you may know that the inboard three bolts on the horn are buried deep, and the rear one has the #2 fuel line, vent tube, and injector harness all playing blocker as you are trying to get that bolt installed. With this intake, there is plenty of room to slide it in and easily access all of the mounting bolts. This is especially nice when it comes time to torque them all down. After you get that set, it is time to install the new cables. Instead of reusing the existing power cable, Fleece sends you a new one, clearly marked where each end goes. This new cable is much more flexible than the factory cable and is the right length to give you more routing options. In addition to the power cable, they provide you with a ground wire to run from the driver-side battery to the intake itself.

Once everything was buttoned up, I grew to like it even more. At first, I wasn’t sure how it would compare to others aesthetically, being that it isn’t as tall and in your face. But there is something sleek and simple about it that I like. I then realized how much access it gives to the surrounding components for ease of service in the future. Without the need for the extra bulk, you can still easily access the engine-mounted fuel filter, master cylinder, fuel lines, and wiring if needed. When you dig into this product, you realize that it doesn’t blindly solve one issue while creating potential for others. This well thought-out and executed product solves a major issue while maintaining ease of maintenance and durability for the long haul. SIMPLE and EFFECTIVE. This product just raised the bar.

Closing

What is truly respectable and admirable about the staff at Fleece is that if you ask them about how one of their products compares to a competitor’s, these guys will answer with facts only. Even if you pry, they refuse to trash talk or degrade another company (even when sometimes it may be justified). These guys come to the table with a well-respected product line, and they let the results do the talking. And for that, we tip our hats to another great product added to the market.