Test Drive: aFe’s Jeep JL With Momentum Intake And Exhaust System

The 3.6-liter 285HP Pentastar engine in Jeep’s newest Wrangler is a tried and true, off-road-capable powerplant. With that said, who doesn’t want more power? Ask that question to the crew at advanced FLOW engineering (aFe) and it’s doubtful there would be an unraised hand in sight. aFe is known for their top-of-the-line, power-adding products and has delivered again with a huge range of options for the JL.

I recently had the opportunity to stop by and discuss some of the products currently available for the JL with the team. Turns out they are so proud of the product line, they not only chose to talk to me about it, they invited me into the R&D center to get a closer look at the process behind designing the Momentum intake system and a sampling of the available exhaust components for the JL. With hardly any begging, Josh Biggers, Manager of E-Commerce, even agreed to let me take their JL out and hit one of Southern California’s trails.

According to aFe, they couldn’t wait to get their hands on the JL when it was released. Since then, they have been busy testing and putting together this beast.

Install Day

Top: Mechanical designer George Chiang shows the 3-D scan of the JL engine bay. Justin poses for a quick shot with one of the 3.6-liter prototypes. Bottom: The final product image of the Momentum series intake and a look at the installed version.

Arriving at the aFe headquarters, I was met by Josh in the lobby, and he promptly showed me around the facility. As we walked, Josh explained to me the process behind designing and manufacturing of the intake and exhaust systems. “It all starts with a scan of the engine bay, and from there we can work up a prototype. The prototypes are then 3-D printed and fitted to the vehicle.” I also learned that the prototypes are initially printed in sections for easier modifications during the tuning process. That dyno tuning is an important differentiator, according to Josh. “The designers will go through several variables, testing for flow and power during the process and make changes as needed,” he said.

Justin Schultz, the head for the JL project, took the time to go a little deeper into this specific project. “There were a few critical design elements that went into this project; we wanted to maintain an air inlet on the top of the unit to maximize water fording capability,” he said. “We also wanted to keep the final unit to as few separate pieces as possible, which was a challenge.” Justin also explained that the tuning process went through several iterations to ensure the final product delivered the perfect sound signature to match the OE look.Both the increase in airflow and the OEM-like appearance are achieved through a roto-molding process. Roto-molding allows the engineers to create shapes that optimize airflow in ways that can’t be achieved with an aluminum pipe. In addition, the finished unit uses of all factory mount points and hardware, as well as locations for the factory lines and fittings.

Overall, the design delivers a 36-percent increase in air flow over the stock intake when coupled with a ProGuard 7 filter media. It translates to a 12 horsepower and 12 lb-ft torque gain, all while maintaining an OE look and fitment. With all that time put into the design, you would assume a fairly straightforward install, right? You would be correct. R&D tech Kristian was nice enough to run through the entire install process, from bare throttle body to ready to running, which took all of 15 minutes in total.

Ease of install and factory fitment were key design elements for the Momentum intake system, as our aFe technician demonstrated with in a few minutes.

Currently, the Momentum intake is offered individually or as part of several power packages; the Momentum GT performance package (available through aFe directly) is one example. The package includes a one-piece housing, two air filters with restoration kits (both dry and ProGuard 7), CAD-designed intake tube with resonator and a Silver Bullet aluminum throttle body spacer for added gains.

After the hood was all buttoned up, it was time to talk exhaust with Josh. “We have a lot of exhaust configurations available,” he said. “We currently have 27 for the JK, and JL units are quickly climbing.” Out of that impressive catalog of options, Josh went on to tell me about the configuration they chose for their signature Jeep. “For this one, we used the Mach Force-XP stainless Hi-Tuck cat-back exhaust for maximum clearance,” he explained. This particular vehicle was also rocking aFe’s Twisted Steel Y-pipe and Twisted Steel Loop Relocation Pipe.

Once on the lift, I got a much better look at all those components.  The system is impressive in both looks and ability to maintain clearance, tucking into the factory locations neatly. The cat-back system splits into three separate pieces for ease of installation and utilizes the factory hangers for mounting. According to Josh, the loop relocation kit offers a solution to the suspension clearance issues that arise with the factory exhaust when you increase travel. “We offer a loop delete pipe, but you sacrifice some torque, so we engineered a way to keep the loop and still allow for the extra clearance,” he said. With the Jeep outfitted with its latest parts, it was time to call it a day and prep for an early morning on the trail.

Clockwise from top left: Exhaust components tucked in place above the factory brace. The technician snugged down the last bolt to affix the tip. The R&D tech worked on another exhaust project. The exhaust was finally installed, so it was time to bring the JL back to earth.

Test Day

Just after sunrise, I hit the road for the short drive to the trailhead.  It didn’t take long to appreciate a few aspects of the previous day’s installations. The first thing I noticed when I started the trek was the exhaust tone. It was a deep growl, keeping a low sound level at idle and cruising speed. It was the perfect balance of aggression without becoming obnoxious. As the morning drive wound through a residential area, there was no worries of awaking the sleeping inhabitants.

That perfect daily driving tone was quickly stepped up a notch as I got the opportunity put the power down on a stretch of empty road. During that burst of acceleration, there was the faint vacuum sound from the intake, which was otherwise silent until it was asked to deliver its full volume of air. Overall, the combination produced more than just noise; it also put a much-needed pep in the JL’s step as I pulled onto the freeway, anxious to reach the trail.

After a strong first impression of the power gains and new voice of the JL, it was time to see how it handled some dirt and rocks. Dagget Creek Path is a moderately challenging trail, featuring more than a few steep inclines and sections of luggage-sized rocks, as it winds its way up and over a pair of Southern California hills. Power delivery was smooth as I crawled up the first sections of the path. With a quick blurp of the fun peddle, the JL easily powered over of a small section of loose rocks and crested a plateau  revealing a view of the valley below.

Cresting the hill to the first plateau revealed not only an epic view of the valley below, but also a pretty decent photo op as the sun started to break through the clouds.

The Jeep performed flawlessly for the remainder of the trail, providing a quick burst of power when needed to overcome a few trouble spots. Soon, I reached the end of the loop and decided to utilize a few dirt flats below the trail for the rest of the testing.  Much like on the hill, the Jeep easily navigated the sand and dry lakebed with plenty of power on tap to push over the small crests and soft patches.

Before I knew it, it was time to return the JL to aFe, so I hit the roadways back. After a day on the trail, the Jeep was refreshingly quiet, with just a dull hum of the 37s and the slight growl of the exhaust both barely noticeable with the windows up. Overall, aFe has put together an impressive selection of parts for the JL. Being able to drive this one has delivered a new appreciation for what a single company can deliver in terms of parts.

So, if you too would raise your hand for more power when it comes to your Jeep, or are looking for a range of other components, give aFe and their family of brands a serious look. I’d like to give a special thanks to willingness of the team at aFe to let me take a closer look at their facility and borrow the JL. For more information, visit afepower.com and the official aFe Facebook page.

Article Sources

About the author

Dustin Singleton

Dustin is an internationally published photographer and the founder of IALS Photography. Managing a successful mobile electronics shop led him to become completely entrenched in the tuner scene.
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