Another Intake?

Wait … Mishimoto already has an intake for the BRZ/FR-S. Why design a second one? As this question crosses your mind, we can provide a simple explanation.

We have had great success with our existing cold-air intake system for this chassis, and the feedback from our customer base has been fantastic. Here is a look at our current product.

After listening to our customers both directly and through web forums, we concluded that a second intake design was necessary for a completely different set of customers. Here are a few plans for our new design.

• Engine-bay mounted, stock-appearing airbox setup
• Easy installation and filter servicing
• Fits with Mishimoto direct-fit oil cooler kit
• Provide power gains over stock intake system

Our current intake system locates the filter behind the bumper. This requires bumper removal for both installation and filter servicing. Although this location would provide a rather cold air charge and would be less likely to experience filter heat-soak, we do realize that some folks are not interested in the slightly longer installation or servicing process.

Additionally, due to space constraints, several aftermarket intake options (engine-bay mounted) are not exactly compatible with our direct-fit oil cooler kit. We wanted to be sure that both of these products would function together without issue.

And finally, power gains. As with any intake upgrade, one expects a bit of extra power and torque, as well as an improvement in engine sound.

Prototype Development

As with other projects, development for this intake starts with stripping away the stock intake system.

We decided to start our system by creating the piping that would route from the throttle body to the air filter. Because we would be keeping the filter within the engine bay, we planned to utilize the stock air duct that feeds the stock airbox.

So we took the necessary measurements and modeled a design in 3D. We then decided to test our new 3D printer to produce a functioning prototype to test fitting and airbox development.

Yes, our new printer does indeed print in Mishimoto orange. Pretty slick! You can also see that this setup places our filter directly in the path of airflow from the grille duct. Below is a straight-on shot of this pipe.

A few things to note about this piece. We are eliminating the noise generator and the intake resonator. A majority of 86 owners remove the sound generator, but we are confident that our customers will be pleases with our intake and with sound it produces, without the additional piping.

We are also utilizing our mass air filter (MAF) housing with an air straightener, both of which are included in our first intake kit. The air straightener helps promote laminar (smooth) airflow past the MAF sensor. This will provide the same drivability you will experience with the stock intake.

Last, we are also utilizing our oiled air filter. This unit provides greater flow and surface area compared to the stock paper filter, which should result in improved power output. This filter is fully serviceable and will not require replacement over time, unlike the stock filter.

Coming Up!

Check back next time for a look at our process for creating the intake box design!

We left off last time with an explanation of our intentions with this intake system and some initial design work to create an induction route to our planned airbox. Now it was time to finish designing this intake system so that testing could be conducted.

Airbox Fabrication

We started developing our airbox with simple metal fabrication. The plan was to put our idea into a physical object and then transfer this to a 3D model. Once in Solidworks, we could solidify the final design and features and use our 3D printer to construct a final prototype for test fitting.

Fabrication begins! A simple box was drawn up and templates printed for our bends and mounting point locations.

Bends were made, holes were drilled, and here is what we ended up with.

We then constructed a lid to contain airflow coming in through the scoop and to reduce the impact of engine bay heat-soak.

As noted in our first portion of this series, we wanted to ensure that out airbox would function with our oil sandwich plate and oil cooler kit. A few aftermarket intake systems are not compatible because they occupy the same space as the fittings we attach to the plate. Check out the clearance shot with our airbox!

We then finished off the base of the airbox and ended up with our first completed prototype. Check out a few images of this!

As you can see, we are using rubber weather-stripping around all the edges. This provides a factory-like appearance and reduces any chances of noise created from vibrating components.

Below is the lid for the box. This prototype unit is void of any mounting points. We will be adding holes to accommodate our mounting hardware.

And our final assembled prototype!

3D Prototype

After completing our fabricated prototype, we set our engineering team to work modeling this box in Solidworks. A few small tweaks and adjustments were made to the design as well. Once we had this complete, we decided to experiment a bit more with our new 3D printer. Printing this airbox was indeed within the constraints of the engine bay size, so we set up the printer and went home for the evening.

In the morning, we were pleasantly surprised with this!

Keep in mind some of the support material still needs to be removed from this printed box. Other than that, this turned out great!

We then installed this prototype in our test vehicle to ensure proper fitment!

3D Models

Check out the final 3D models for this full intake setup!

And one with the lid removed!

Coming Next!

With a solid design in place, it was time to test this setup to see what kind of gains we could achieve in terms of power output.

Check back next time for a look at our testing process, results, and a video from our dyno pulls!

After solidifying our product design we needed to capture data to verify the design and determine if any changes were necessary. We strapped our test vehicle to the dyno and began making pulls! Check out a compilation video from the dyno testing. The audible difference in intake tone and volume is quite noticeable when comparing the stock setup with the Mishimoto prototype.

Testing Results

On to the important part, results from our tests. Intake upgrades generally are subject to a decent amount of speculation, because of the outrageous claims often made by component manufacturers.

Here at Mishimoto, we perform extensive, repeatable testing to ensure that our results are 100% accurate and are not skewed in any way. Below are some of the constraints and details for the testing of this vehicle!

• Testing day ambient temperature: 60°F
• Testing day ambient humidity: 18%
• Data collected: horsepower, torque, air/fuel ratio (AFR)
• Numerous runs were made until each setup resulted in 4–5 consistent pulls; average run from this group was used for comparison.

Check out the power comparison chart!

The Mishimoto intake begins to separate itself from the stock system at around 5,300 rpm and continues to provide gains through redline. Through most of this range we are seeing gains around 2–4 whp with maximum gains of 7 whp and 5 wtq at just under 7,000 rpm. These are fantastic gains for a bolt-on intake system, and our team was very pleased with the results.

One topic of conversation revolving around intake results is the AFRs produced. Our intake features a mass airflow (MAF) housing diameter that differs slightly from the stock setup, this would have an impact on AFRs. Check out the chart constructed from the pulls above!

Our intake provide a similar AFR path compared to the stock setup. Ratios are slightly richer from 4,000 rpm to 6,000 rpm and then become slightly leaner until redline. Although leaner, these AFRs are still well within a safe range and will not have a negative impact on the integrity of your vehicle. Another positive data point from testing!

The last chart we have to show is a comparison of air filter surface area. As we alluded to earlier in this article, the surface area of our oiled filter is far greater than the stock paper unit.

Final Product!

After obtaining positive testing and fitment results, we worked up a final prototype that appropriately reflects our final design. Check out some shots of our final airbox!

Here’s a closer look at the threaded rivets that secure the lid to the base of the airbox.

Check out the front duct that functions with the stock air scoop.

Below is a shot of the airbox lid complete with subtle Mishimoto logo and noise-eliminating weather stripping!

We also have the final hardware packet for this kit. Four socket cap bolts and washers attach the lid to the airbox. Two other bolts and one nut secure the box to the vehicle via the three mounting brackets attached to the box.

Check out the final assembled airbox!

Fully Installed Kit

Check out a few shots of this final kit fully assembled and installed!