Compromise is all about finding balance. From the design studio to the streets, these Broncos have had to compromise on a few topics to make them adequate on the pavement and functional once that asphalt runs out. One of the main topics of contention between the punchy 2.3L and 2.7L workhorse is the airbox for both intake systems. While both parties have reached an agreement, for now, some renegotiation is in order, and we’re here to mediate. 

Looking back to our first post, Ford opted to share the intake system’s airbox between the four and six-cylinder powerplant options. While this decision slimmed production costs, it also squandered both engines’ potential. If there’s an EcoBoost badge on a Ford, it’s almost guaranteed that enthusiasts will demand more boost from the system. That extra pressure will be in vain, though, since this airbox is one of the gatekeepers of power. Until now, that is. 

Our airbox was just a collection of pixels in our digital workspace when we left off. Finally, this virtual representation has come to life after a round of prototyping and production. Our production samples have arrived at our R&D facility, and we’re eager to show them off. 

Clad in its rugged cross-linked polyethylene, this new airbox is more than equipped to handle the harsh heat from the engine bay while shrugging off any other hazards encountered on off-road excursions. In addition, this material choice allowed our engineer to utilize rotational molding manufacturing, giving Ye much more lead in striking a balance between expanding the box’s size while ensuring fitment. 

Growth is always a necessity for improvement. In this case, physically growing the airbox’s size was vital in giving both engines access to a greater air volume while clearing room for our much larger filter. The increased surface area combined with the more free-flowing element reduces restriction right at the start of the system, allowing the Bronco to take deeper breaths. Speaking of filtration, we know the right element varies per environment. To ensure we’re keeping these filters properly flowing while blocking dust and debris, we’re also offering these kits with the option for a dry or oiled filter. The status of your filter can even be determined with a quick peek through our access window. 

The security of the Bronco’s fresh air is vital, so we took measures to ensure that the air is consistently flowing to the correct channels. For starters, Ye included CNC-machined billet aluminum mounting pegs to properly slot the box into place, combined with a sturdy steel bracket to keep it from wiggling free. To top things off, this box utilizes our patented filter grommet design to securely seal off the airbox from outside debris and keep the fresh air flowing to the turbos. 

Power is already plentiful no matter which engine found its way into your Bronco. But, even with that provided grunt, there’s always room and a desire for more. The turbocharged platform lends itself to oodles of potential, but the shared airbox across the lineup stifles the EcoBoost with its airflow compromise. With the terms of this airbox agreement kicked off, the Bronco is already starting to breathe better, but each engine still wants its own separate agreements. 

Lifting the hood on your 2.7L powered Bronco is like unfurling a roadmap. Roads and trails are heading in every direction to countless destinations that all seem to cross, merge, or repel each other at some point that can make anyone’s head spin. However, carefully examining this labyrinth of possible directions can make the right path shine through and easily plot the best destination for your journey. While not quite as intricate as the highway system, finalizing this intake system still took some expert navigation.

It’s a maze under the hood, but our engineer, Ye, plotted a route with the plans laid out in our last post, but now that our production sample has arrived, we’re ready for the final journey. Before we set off, though, let’s take a closer look at the new kit. 

Base camp for our intake journey was set up with the fresh new airbox we designed to be compatible across the Bronco platform. Like this new airbox, the remainder of this kit utilizes the tough cross-linked polyethylene, or XLPE, rotational-molded construction. This method gives us the best of all options. While we might harp on plastic components, this material choice still has plenty of benefits. For starters, XLPE is a hearty material that’s more than capable of standing up to the harsh conditions of an engine bay. It also gives our engineers much more creative freedom when shaping these new designs, which is especially important for this particular kit. 

It’s a tight squeeze completing the channel from the driver’s side turbo to the airbox. Even from the factory, this tube needed to bob and weave through intercooler piping while also providing support for that same piping system, on top of maintaining airflow. Long story short, Ye had her work cut out since we still needed to work within these constraints while reducing restrictions within the intake system. This is where the construction choice comes in clutch since our pipe accomplished all of these thanks to the precise notches and bends Ye was able to incorporate into the final design.

Regarding the merger, there was a little more room to expand. Unfortunately, the OEM design left us with sharp bends right after the air filter, which is less than ideal for airflow. So ye re-engineered this merger with softer bends and a greater internal volume to give the airflow a smoother path to the turbos. To top things off, these new-fangled pipes are sealed together with our rugged and slick silicone couplers for a secure charged air channel. 

With the 2.7’s engine bay labyrinth conquered, the only thing left was to see how much extra lung capacity this kit provided to our wild wandering machines. Stay tuned for our dyno testing results coming soon. 

To find out just how much this kit is contributing, we started on our flow bench. The SuperFlow SF1020 is equipped with an array of air pumps and precise air metering equipment that provides our engineering team with an instant calculation of the airflow restriction between the stock system and our new design. If you want to dig deeper into our flow bench system and testing methods, make sure you head over to our in-depth tech article – Flow Bench Equipment Profile.

The first prong of our intake’s enhancements comes from airflow. This kit utilizes both an enlarged airbox with a performance oiled or dry filter that gives the turbo twins some more breathing room. Additionally, our engineer, Ye, opened up the Bronco’s air passages by increasing the inlet tube’s cross-sectional area by 20%, allowing for an increased volume of air to pass through the system. The result of these updates is a restriction reduction of 39.6% over the stock system.

How do these deeper breaths affect the overall performance of the Bronco, though? We’re glad you asked! While these Broncos are managed with a speed density tune, coaxing out additional power gains with OEM programming is challenging. The basic operation of these tunes typically compensates for the additional airflow and will typically maintain power figures. However, in this case, we didn’t have typical results. Given our spacial and tuning restrictions, we still added 7.5HP and 7.4TQ to the 2.7L’s powerband on the stock tuning.

While the 2.7L EcoBoost is already a powerhouse, we enthusiasts always demand more. Topping 415HP isn’t enough, so we’re always searching for every additional horsepower we can find. After our time spent searching through the Bronco, we’d suggest starting with breathing techniques. Make sure to upgrade your 2.7L Bronco’s lung capacity today!