Intake Comparo: 6.6L Chevy Duramax Intake Systems Put To The Test

LEAD-ART-DA

Selecting the right intake for your truck can be quite difficult. How do you know what to use and what works best for your particular application? Most people you might ask have only tried one or two different intakes and they generally are going to recommend what they purchased, not based off any actual needs or use. Here at Diesel Army we like real world reviews that the average diesel guy can relate to, so why not test out some intakes and show you first-hand the comparisons. We took five leading intake setups and tested them each on our 6.6L Duramax to see how they all stack up.

Our Setup

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The Test Vehicle:

  • 2012 Chevrolet 6.6L Duramax (LML)
  • 13,119 miles
  • Silverado LT crew cab(4 door) 2wd 2500HD

Testing conditions:

  • Cloudy with a temperature of 75 degrees,  duepoint was 57.9 degrees and humidity was 55.

The one thing that is most often overlooked and actually the most important in the world of selecting an intake is your intended use/needs or particular application. Horsepower and torque are NOT the most important factors here and they certainly don’t give you a complete picture of your air filtration system or needs. Factors like improved fuel economy (especially for towing), flow and filtration, fit and finish, ease of installation, quality components, warranty, and more all play important roles in the choices represented here.

The Set Up

In order to keep everything even keel and give you a true comparison, we used a single truck for the testing. We let the truck get up to operating temperature and made a pull on our dyno for each test. After each run, the truck was allowed to cool back down and after about ten minutes, we made another dyno pull. Assuming the pulls were close for consistency, we let the truck cool down and then swapped the intakes. If the runs weren’t close, then we looked for what may have caused the anomaly, and repeated until we had a consistent solid result.

We should also note, it’s not necessarily apples-to-apples here as open element, cold-air, and ram air applications all function a bit differently and without having the truck up to highway speeds with forced air and under load, the only way to simulate this was by keeping the hood open and we ran a fan to help mimick “real world” conditions for the kits that needed this. And a BIG disclaimer here, these kits are measured from the manufacturer to perform better under load, with more hp and torque “under the curve” so our dyno results are a very small portion of this overall review and would vary in real world conditions.

The Dynomometer:

At the Diesel Army tech garage we are fully equipped with a Dynojet 224xLC chassis dyno installed in our home office testing facility. This is a 2,000 horsepower, 200 MPH dyno that is installed in-ground. If you aren’t 100% familiar with dynos or how they work, our sister magazine Chevy Hardcore featured a dynamometer 101 story which gives some great information worth reading to get a better understanding of the operation.

Airaid_lead

Airaid MXP; Part #200-295 

The first intake kit up for testing was the Cool Air Dam System from Airaid. According to the experts at Airaid, “Cold air is denser than hot air, so cold air packs more oxygen molecules into an engine. More oxygen means more complete combustion, and more combustion equals more power. Our computer-designed Cold Air Dam (CAD) helps to separate the Airaid premium filter from hot engine compartment air, while supplying the filter with plenty of cool outside air. This cool, dense air charge, is the key to getting more power from your engine.”

Ease of Install

Once the factory intake has been removed, the main filter housing is set into place.

Out of their Cool Air Dam System options, we choose to go with the MXP series. Speaking with Airaid, they shared that “The MXP series is designed for high-performance diesel applications and we start with a new one piece roto-molded air box that addresses all the shortcomings of the restrictive factory design. Then we add a new air intake tube constructed of cross-linked, high-density Polyethylene that is designed using extensive computer modeling to maintain proper mass airflow readings and calibration.”

After working with and speaking with our tech who performed the installs and testing for the day, here’s what he had to say about the Airaid MXP setup as far as the installation was concerned: “The Airaid kit was very easy to install and it doesn’t hurt that it’s also easy on the eyes,” shared Sean Goude, Master Technician for Power Automedia.

Quality of Components

“From a functionality standpoint it used a cold air box which grabs air from the factory hole in the fender but also has an inlet at the bottom that reaches down by the bumper and gets cool air from that location as well, which is a pretty slick set up! The kit has a single inlet tube instead of a two piece, so it takes a little jigging to slide it in place and uses the hood as the lid to seal to. In reference to performance, we were pleased with the dyno charts and increased air flow the MXP provided. Overall, this kit was a winner and proven performer,” continued Goude.

(Left) Before securing anything, install the intake tube. You may need to move the filter housing around a little bit to work the intake tube into place. (Right) Once the parts have been lined up, it's fairly easy to start securing everything in place.

Power and Torque

We asked Trent McGee over at Airaid to tell us a little more about the system, “The Airaid MXP Series Intake Systems are designed to bolt into place (there’s no drilling or trimming required) and work right out of the box with no tuning required. The complete replacement airbox adds several cold air inlet ducts, while the oversize filter and replacement intake tube optimize airflow to the engine, and more air equals more power. Our systems increase power, lower EGTs, and improve fuel mileage all at the same time.” Below you can see our high run gave us 325.72 hp and 546.08 lb/ft of torque.

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(Top) Back to back runs with the AIRAID installed. (Left) A nice thing about most of these kits is that they re-use the factory sensors. (Right) With everything installed, the final step is to add the gasket around the top to seal the box against the hood.

Fit and Finish

With both form and function the Airaid MXP series lines out to be a very worthy contender. What this all means is a simple-to-install system that was designed using extremely sophisticated technology to increase airflow while maintaining proper air/fuel ratios, therefore eliminating the need for re-calibration once installation is complete. Just bolt it on and go. Like all other Airaid Intake Systems, the MXP includes an Airaid Premium Filter that is sized to maximize power and efficiency.

Bullydog

Bully Dog Rapid Flow; Part #53153

Next up was the new Intake System from Bully Dog. We quickly strapped on the Bully Dog Rapid Air Intake System and put it to the test. But, why the Rapid Flow Air Intake? We spoke with the folks over at Bully Dog and they had a lot of good information to share about their products. They provided us with important feedback about this design and what makes it different.

Ease of Install

According to our master tech this kit had one of the easiest install processes out of the bunch. With only 16 total steps, the install was very straight forward and painless, and because the filter box and elbow install as a single unit it helps cut down on install time (although, it is a bit of a puzzle to fit it in place at first). Some of the smaller parts (washers between Mass Air Flow and new intake tube) were a little difficult to get to, but overall the installation was simple and quick.

Quality of Components

When we met with Bully Dog they lined out a few of their key features which they focus on for each application and development. The team at Bully Dog creates their intake products with a few specific goals in mind:

  • Keeping hot air out of the intake stream – Bully Dog’s Rapid intake is precision designed and tested for optimal cold air flow and decreased air turbulence.
  • Designed to pull air from cold air sources – Pulling cold air from within the engine bay to increase the amount of cold air that is fed to the engine, in turn increases power.
  • Accommodating a high-flow cotton gauze air filter – For better filtration and performance.
  • Improving the look of the engine bay with style – Bully Dog intakes are designed to give your engine bay a nice, sleek, custom finish.
  • Clean Install – Quick and easy install achieved by snap-on parts and easily assembled fittings help make the installation process simple and worry free.

We spoke with Adrian Croot of Bully Dog about their intake kits and he had the following to say about their quality and testing procedures: “All of our intakes are injection-molded and fully enclosed with 8-ply filters. We do all development in-house at our location in Idaho. They are all dyno tested and road tested before we ever go to market and we also test all of our intakes paired with our tuners to ensure they work together nicely.”

(Left) The first part to be installed is the elbow that connects to the plenum. (Right) Factory sensors ensure that no additional calibrations are needed.

Power and Torque

In gauging what to expect, we checked their website and found Bully Dog’s Rapid Flow Air Intake System delivers cold, dense air to the vehicle’s engine, outperforming OEM air intakes by providing additional horsepower, torque and fuel efficiency. Our numbers came in at 313.65 hp and 511.26 lb/ft of torque. Bully Dog’s enclosed intake system helps keep hot air out of the intake stream by targeting cold air sources specifically designed to optimize airflow and the high-flow 8-layer cotton gauze filter provides maximum filtration to protect your motor without limiting airflow. 

Bullydogshootout

(Top) Back to back runs with the Bully Dog intake installed. (Left) Serviceability is key with this kit. Once everything has been installed, the lid simply snaps into place. (Right) Finished installed system.

Fit and Finish

One of the main points of joy for Sean Goude, our tech, was the sealed box on this kit and the lid attaching with clips and not bolts. He really liked the serviceability and to know that he could remove the lid faster to get to the filter without tools. Goude really likes the look of this kit and the functionality was top notch. The injection-molded design upgrades the engine bay for a truly custom looking finish.

AFE_lead

aFe Power Momentum HD; Part #50-74005

Continuing in our review of the “coolest” intake kits on the market, we reached out to aFe Power to test out their Momentum HD air intake. In researching the product, the company offered a variety of information about their intakes and what makes them standout from the competition.

Ease of Install

The first step when installing the aFe kit is to install the filter into the housing.

This kit was one of the favorites of our tech. Goude shared, “This kit came with a large filter that was a bit different than any of the other kits we were testing,” continued Sean. “The air box is sealed and has two inlets. The factory hole in the fender and the front top comes with a removable plug to allow more fresh air in or to totally seal off the box. This air box pops in just like the factory, no bolts required. There is, also, a sight glass on the top so you can look and see how dirty the filter is, to help know when basic maintenance is needed.”

When asked if there were any drawbacks to the kit that Sean ran into during installation he shared, “The only drawback I saw was the serviceability. You can easily see when you need to swap the filter but you have to almost pull out the entire kit to make that swap. But overall, this kit would be a winner with most customers looking to add an intake system to their diesel.”

Quality of Components

When we spoke with aFe Power to find out more, they shared: “The Momentum HD sealed air intake system is designed using the most up-to-date engineering tools and techniques on the market today. This intake system is a one-piece sealed housing with a built-in sight window, and includes a massive 1,000cfm air filter.”

Jason Bruce, the Director of Marketing for aFe went on to share that, “Our engineers are constantly testing designs and developing new products to make even more power. We prove each design with exhaustive testing before it ever comes to market. Each and every intake is tested and real results are posted so consumers can be better informed as to what they are purchasing.”

(Left) Once everything has been assembled, the box/filter can be set into place. (Right) Next, the factory sensors are re-installed into the intake.

Power and Torque

Like we mentioned, this wouldn’t just be another “Intake Power Test” as there are so many other parameters to keep in mind when looking for an intake system that will fit your specific needs and budget. When strapped down to our dyno, the aFe Power Momentum HD system gave us 323.53 hp and 533.31 lb/ft of torque. Although the sealed systems do tend to perform a bit better in this sort of stand still testing environment, so far we’ve had good success with all three style of systems.

AFEshootout

(Top) Back to back runs with the aFe Power intake installed. (Left) It takes a little bit of working the intake tube back and forth to find the right fit, but it eventually falls right into place. (Right) Finished kit.

Fit and Finish

Looking at the features more in-depth, the aFe unique one-piece housing has a few key benefits. The smooth one-piece sealed housing with auxiliary air scoop is used to eliminate the use of multiple-piece housings to help ensure the coolest air intake charge. A urethane plug is also included for those cold weather applications where you want to block the auxiliary air scoop. A large, clear sight window is used for hassle-free filter inspection.

According to aFe, “The 10-Layer Pro 10R Performance air filter used in the Momentum HD is designed around a massive 1,000cfm performance 360-degree radial flow air filter with 10-layers of progressive cotton media providing 99.59% cumulative efficiency. The unique air filter to housing interface allows for maximum filter size which increases the available air volume while simplifying the installation process. The air filter is wrapped in reinforced metal providing maximum strength to help prevent filter collapse.” Overall this kit is sleek and sexy and definitely adds a nice touch to the engine bay while still packing a punch. Utilizing premium stainless steel T-bolt clamps and a 2-ply reinforced silicone hump coupler at the turbo for strength and durability, this setup also adds a very secure and worry-free installation.

AEM

AEM Brute Force HD; Part #21-9032ds

Up next, was the Cold Air Intake system from AEM. This kit was specifically developed for 2011 and 2012 GM 2500HD and 3500HD trucks with the 6.6L Duramax Turbo Diesel engine.

Ease of Install

When speaking with Goude about the specifics of the AEM installation, he shared: “This kit was probably the most straightforward out of all the installs. Complete with a nice brace piece to attach the tubing to the filter enclosure for a really stable feel.” Sean continued, “Making use of the factory filter and being a nice sealed box, make this kit a nice and easy upgrade to any diesel. However, this kit had the second most amount of steps in the group tested. And although it’s the most straightforward of the group to install, it’s still fairly labor intensive – but nothing that can’t be handled in the home garage.”

Quality of Components

The AEM intake system is extremely well made and thought out from start to finish. Part #21-9032DS, which was the unit we tested, features a fully enclosed rotational molded plastic air box, a two-piece rotational molded plastic air intake tube, a high performance oil-free Dry Flow air filter and AEM’s Filter Minder gauge to help keep an eye on the filter. The oil free Dry Flow air filter provides high air flow with great filtration and it’s washable and reusable so with the included Filter Minder Gauge, you know exactly when your air filter needs to be serviced. This Minder Gauge was another favorite of Goude’s, “It has a nice formed plastic enclosed box that utilizes the filter minder to keep you informed on your filter life without having to get any tools out to check.”

(Left) Here's where the intake tubing is run. (Right) Next, the factory sensors are hooked up.

Power and Torque

The fully enclosed air box design helps to maintain the IAT (intake air temperature) close to ambient for consistent horsepower and torque. According to AEM, “The Duramax engine is already producing a tremendous amount of power and torque, so our engineers went a step further to enhance its low and mid-range power and torque output.”

When we asked George Hsieh of AEM about how this kit is different from others on the market, he said he shared: “The AEM 21-9032DS is designed to focus on low to mid RPM range gains where the truck spends most of its life. The AEM intake’s enclosed air box channels cool, ambient air flow to the AEM Dry Flow filter which results in consistent gains in power and torque over the stock equipment.”In AEM’s dyno testing they report an estimated 14 hp and 30 lb/ft of torque over stock. Our tests saw a high run of 300.02 hp and 485.64 lb/ft but also showed one of the most consistent low and mid-range power and torque gains, so this intake is truly advantageous for the haulers or pullers looking for that low-end power.

aemshootout

(Top) Back to back runs with the AEM intake installed. (Left) This was the only kit that didn't re-use the factory filter minder, AEM's kit came with its own. (Right) How the finished kit looks.

Fit and Finish

Overall this system has a specific performance design in mind while still maintaing factory parameters. By utilizing some of the factory components, AEM was able to achieve their design and performance goals, while offering an affordable system to the diesel market. With quality components and hardware, and OEM quality level design, the AEM sealed system provides a ton of bang for the buck.

KN_beauty

K&N Filters 63 Series AirCharger; Part #63-3077

The final kit in our testing pool was the 63 Series Intake Kit (AirCharger) from K&N Filters. The AirCharger intake systems from K&N feature an open element K&N filter along with a sheetmetal enclosure that seals once the hood is closed.

Ease of Installation

“This kit is very simple to install and K&N’s promise of being able to do it in 90 minutes or less, is absolutely true,” continued Goude. “This kit doesn’t feature an enclosed/sealed box like some of the other kits we tested, but it does utilize a sheetmetal enclosure that seals to the hood. The instructions are straight forward with a process that’s really easy to follow. One thing to keep in mind is that this setup has a three-piece intake tube that includes the MAF sensor tube in the middle. Having these three pieces means a little bit more time is needed to align and set everything in the proper locations, but it’s not difficult at all. This kit would definitely be a home run for a first time DIY modifier thanks to the detailed instructions.”

Quality of Components

KN_box

Like the other kits, the filter housing is the first component to be installed.

The 63 Series kits are truly state of the art. K&N starts with the largest conical shaped High-Flow air filter they can fit into the engine compartment while using factory holes and mounting points. This extra filter size provides more airflow at lower restriction than a standard K&N O/E replacement filter, which is limited to the size of the factory air box.

The oversize air filter also captures and holds more dirt increasing the service life before a cleaning is required (up to 100,000 miles). The filter is isolated from high engine temperature by a heat shield designed to lower the temperature of the air entering the engine, which in-turn increases horsepower. The filter is then attached to a rotationally molded tube made from interlaced High-Density Polyethylene reducing turbulence and accelerating airflow into the engine. This tube is connected with adapters made from high-strength materials such as silicon and reinforced nylon.

Power and Torque

We spoke with Lucio Tapia of K&N, and he had the following to say about their intakes, “Our systems are built for reliable horsepower and added diesel performance. If we can’t increase a vehicle’s horsepower we won’t build a system for it, it’s that simple. We establish a stock baseline horsepower with our in-house dynamometers and then we work to get the most horsepower gain while still providing superior filtration and protection. Our numbers aren’t based on the single biggest gain from one particular vehicle as all vehicles will vary. We take an actual average of runs and different vehicles during our R&D. Many times an identical vehicle will perform differently and we want to ensure repeatable numbers you can count on for great diesel performance.”

Tapia went on to say, “Many K&N Diesel specific Air Intake Systems are street legal in all 50 states and include a California Air Resource Board (CARB) Executive Order (EO) number that ensures the kit has been tested to comply with emissions standard.” After getting the info straight from the experts we put the system to the test on our dyno and got some very respectable results, with 309.39 hp and 503.45 lb/ft of torque.

K&Nshootout

(Top) Dyno sheet with the two runs. (Left) The three-piece intake tubes are aligned. (Right) With everything run, the factory sensors are re-installed.

Fit and Finish

Due to the “open element” design of the K&N AirCharger system, it went together quite nicely. Aggressive looks and performance are achieved without sacrificing functionality or OE styling. Our tech, Sean Goude mentioned, “I really liked the overall simplicity of the K&N design, paired with some aggressive notes including the large K&N filter and industrial/mechanical styling cues which blended perfectly.” We couldn’t have said it any better!

Peak Power Numbers Aren’t Everything

In a perfect world you could compare intakes in an apples-to-apples way from a horsepower and torque standpoint. Despite having a great tool in our Dynojet, the reality is that air intakes are particularly hard to test because in a “real world” environment the hood is closed, and the vehicle is moving at speed. Thus, an intake designed with a front cold-air source in the real world may function with lower horsepower on the dyno. In addition, an open element design that might function less efficiently with the hood closed gets the advantage of the hood up during testing. Furthermore, improvements in Diesel engines are typically more pronounced at mid-range and lower-RPMs than you would typically measure on a chassis dyno where “peak” dyno numbers get so much attention. So what does this all mean? It means that there is a lot more to a cold-air intake than a static chassis dyno test, which is why we went the extra mile to show other important parameters.

Final Thoughts

With our “hands-on” reviewing and testing with some of the top-rated kits currently on the market, we were able to find that each kit certainly has it’s own unique features and added benefits. With all of these kits being from highly reputable industry names in the diesel market, they all offer great options depending on your overall objective when adding this modification. Like Lucio Tapia from K&N mentioned above, the exact same vehicle could very well perform differently on any given day based on any number of factors.

Some systems are easier than others to install and they all work a little differently, but each kit is built for a purpose. To help increase the amount of cold air flow to your engine, engine filtering, horsepower, torque, fuel economy, under-hood appearance, and the overall functionality and performance of your engine. Ultimately, choosing the right one for your application will be based on intended use, personal preference, and budget. Stay tuned to Diesel Army as we continue to undertake our mission of real-world testing on the diesel markets’ leading upgrades!

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About the author

Nicole Girkey

As an automotive editorial Ninja, Nicole has woven her way in and out of various aspects of the automotive print and editorial industry for over 15 years. Her recent obsession, diesel trucks, with a focus on sled pulling, keeps her in the dirt. In her off time, she is steady working on creating and molding the next generation of “car guy” with her husband and son, little Cooper.
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