We spent a long time designing and testing our BRZ intake system to ensure that when our customers recieve the part, it will make the HP we claim, not cause any drivability issues, and be easy to install. After seeing many intakes with bogging issues, drivability issues, and poor MAF sensor placement, I knew that our intake would be a hit. If you missed the first blog post about our intake and design process, you can read up about the initial design in PART 1 located HERE. Part 2 of the BRZ/ FR-S intake design, goes into more details about our intake, why its better than others and it reveals a couple things we had been keeping secret.
Dyno Proven Horsepower!
The most important reason for making this part is to add some power to your car. You can see from the above graph that this intake adds a few extra HP. This test was done on a bone stock BRZ with no other mods and no ECU tune, and with a solid 4 Wheel HP gain, that isn’t too bad! Like most intakes for cars it mainly effects the HP from the midrange RPM to redline. In this case with as light as this car is, this is something you will surely notice.
How did we come up with this design?How does it work? Is it safe? These are important questions to answer for anyone looking at an intake for their car.
No ECU Tuning Required!
Equally important to HP, is making sure the intake is 100% safe to bolt on, and doesn’t require an ECU recalibration, or retune. This is important to understand as intake systems are not all created equal and if not made correctly, they can mess up how the car runs and lose power. On the other hand, the may trick the ECU into making power, by leaning the AFR out, which can really mess up how the car runs after an ECU recalibration is done. This can lead to very dangerous lean conditions and could lead to engine failures.
In the world of intake systems, anytime a MAF (Mass Air Flow) sensor is used to meter airflow to the engine, its important to design around this to ensure that no ill effects occur. We mentioned leaning out the AFR with a poorly made intake is bad, but what is AFR, and what is safe? Check out the first blog post about this as there is a good explanation of it. For now, lets just say that an intake should replicate the stock AFR curve in order to be 100% safe to install on any car in any stage of tune.
Intakes generally require an ECU retune(or recalibration) to compensate for the change in airflow readings. This is because intake manufacturers can use a variety of different style MAF flanges, tubing sizes, and even bends before and after the MAF sensor can all create different readings for the ECU. These readings can affect how the car runs in all conditions, but most importantly under full throttle. An intake can cause a dangerously lean condition under full throttle, which can lead to engine damage or worse yet a catastrophic failure. These are all key factors in how we design an intake for the BRZ/FR-S.
Using the above graph you can see the AFR curve of the stock BRZ/FR-S intake, compared to the PERRIN Cold Air intake. You can see how the AFR is virtually the same from 4000 RPM to redline. This is important to understand as this means, its not running too lean, or too rich under full throttle, which both can loose power or lead to dangerous conditions. As more and more ECU reflashes or tunes come out that are based on stock intakes, you can be ensured that they will still be safe using our intake.
True Cold Air Intake
This feature is what really makes ours stand out from other intakes being offered. From the pictures below, you can see that we put the air filter in the bumper, not in the engine bay. This is the best place to put the filter to ensure your engine gets as much fresh cold air as possible. This does add some time to the installation (30 minutes or so) because the bumper has to come off to install it. We include very good instructions on how to do this which makes it easy for anyone with a set of basic tools to do. So don’t be scared by the fact the bumper has to come off!
Why is this true cold air so important? For a Normally Aspirated engine, every little thing counts. Dropping the air temp entering the engine even a coupe of degrees will make a difference in HP gained. So we took it a step further to ensure there was perfect cold ambient air for the intake to suck from.
The above diagram you can see how the air flow path as it enters the lower bumper opening and toward the intake. As air enters the lower grill it’s split into two directions, through the radiator and then up behind the bumper beam toward the intakes “ram air” tube. Naturally this would be a good place to get air from as its nice cold ambient air from the front of the car. This is why we put our intake and filter in the bumper, to make sure that it would get the coolest air possible at all times. You can see in the diagram below that the filter is hiding behind the bumper above the bumper beam where the air swirls around it.
Why did we go to all these lengths to get fresh air when the stock intake has a nice ram air scoop built in to the car? Simple, the” ram-air-scoop”, only provides fresh air to the OEM intake system, not ram air! Using this to “blow” air over a filter located in the engine bay, or into an open air box doesn’t work. Since most of the big aftermarket intake companies are using an air box type setup that don’t really seal to the OEM plastic scoop, this means that some amount of hot air will get into the intake. That means some loss of potential HP.
How did we figure this out? We thought it might be cool to use the scoop to blow air at a filter and create a short ram type intake. To test how much air really comes out of scoop, we setup a test while the car is bolted to the dyno. We removed the air box, fired up our dyno fans and took some air flow readings using my trusty anemometer.
The findings were very interesting. The test was done with the front bumper on and the car was completely stock. With both dyno fans blowing into the lower bumper we measured a constant 35MPH. With the air box removed, we were measuring a whopping .5MPH! Yes, virtually nothing! I couldn’t even feel air coming out. The next test was removing the plastic air diverter which rests between the fresh air scoop and the lower portion of the bumper. This part is installed to help block some of the air from blowing up and around the radiator. With the diverter removed, there was a nice steady noticeable amount of air flow coming from the scoop at 1.5MPH. This sounds like it would be a great way to make our intake system get a little more flow and cool air, or would it…
After testing this on the road, we found this was a really bad idea. The added pressure and airflow while driving at 45MPH or more would cause the car to run poorly and actually die if you push in the clutch! So the plastic diverter got re-installed and the PERRIN intake would be designed around utilizing this part.
In the above picture you can see the final product and filter, along with where its placed behind the bumper. The filter is placed between the bumper beam and plastic diverter to allow for maximum air flow around the filter along with a perfect cold bath of air surrounding it. You can also see the 2 piece custom filter that we include with all our intake systems. This 2 piece design allows the main portion of the filter and intake to be left in place and just the foam portion of the filter be removed for cleaning. This also makes for a much easier cleaning and re-oiling process. It allows you to wash, dry and apply oil much easier being able to handle it and wring it out.
To recap, the PERRIN BRZ/FR-S Cold air intake is designed to perform safely and work with any ECU tune, be installed by anyone with basic tools. It makes a decent amount of HP, adds some cool new sounds to your BRZ, and all that for a reasonable price. This hits on all the important things customers are looking for in an intake system, so give us a ring and lets get one on order for you!
What Is The Future For The PERRIN Intakes?
You may have seen the below graph from past posts. This is showing a special 3″ intake system designed around cars pushing the normally aspirated power to the max. This intake is NOT safe to bolt on your car. It requires an ECU re-calibration in order to work. That means our ECUTEK tuning tools must be purchased in order to safely run this intake. We are not releasing this intake to start with because 90% of our customers are not going to want to be forced into spending $850 just to run an intake. This intake is for the future, where there are more customers running our ECUTEK ECU reflashes or tunes, and we can simply send them a map to allow this to be safely ran.
But to entice those who might be interested in this option, you can see below that the intake with a custom ECUTEK Tune from PERRIN on top of it, can make for a huge HP gain. Look for this option in the upcoming months.