The Top 5 Subaru BRZ, FRS, and GT86 Performance Upgrades. The Subaru BRZ, Scion FR-S, and Toyota 86 share a chassis and are powered by Subaru’s FA20 engine, a 2.0L flat-four. Despite the fact that a turbocharged FA20 engine was produced, the BRZ and its siblings are powered by the naturally aspirated FA20D. The second generation BRZ and GT86 were released in 2021, with an updated exterior design and the addition of a large 2.4L engine.
The 2.0L BRZ produced 197-205 horsepower and 151-156 pound-feet of torque. While these figures may not appear to be appealing, the cars’ approximate 2,700lb curb weight makes them a joy to drive. They are similar to Miatas in that you would never describe them as fast, but rather as very quick. Their lightweight, low-center-of-gravity design allows for excellent cornering and a lot of fun.
If their 7.6 second 0-62mph time doesn’t pique your interest, there are a few simple BRZ performance mods that can be installed to give these small engines a little more oomph. This guide will go over the top five bolt-on mods for the Subaru BRZ, FRS, and GT86.
With a few thousand dollars in mods, the FA20 engine powering the BRZ, FRS, and GT86 can add about 50whp.
This mod guide will be specific to the first-generation BRZ. While the fitment for second-generation models will differ, the overall gist of the guide remains the same. Despite having a larger 2.4L engine, the FA24 used in the 2021+ BRZ and GT86 is naturally aspirated, so the recommended mods will be the same as for the FA20 BRZ and GT86.
Power Loss on the BRZ at 4,000 RPM
Before we get into the specifics of the mods, we should talk about the FA20D’s natural power drop. A stock FA20’s natural power band has a terrible torque drop from 3,500 to 4,000 rpm. This can make your car feel sluggish when accelerating hard.
If we look at the graph below, we can see that torque starts to drop around 3,250rpm and reaches its lowest point at 4,000rpm. From there, it begins to climb again, and it fully recovers around 4,500rpm.
The design of the OEM exhaust manifold/headers is primarily responsible for the torque drop. As a result, we can thankfully smooth out this dip with the addition of some performance headers and a proper flash tune or custom tune. It should be noted that just adding headers will not solve the problem; you must also add a tune.
Performance Mods for the BRZ, FRS, and GT-86 – Best FA20 Upgrades
Best Subaru BRZ Performance Mods
Among the best BRZ engine upgrades are:
- Exhaust Catalytic Converter
- E85 Fuel
You’ll notice that we didn’t include any major modifications like turbochargers or superchargers. This guide focuses on simple bolt-on modifications that will result in some nice and affordable power gains. To make serious power with your BRZ, you’ll need to investigate forced induction, which we’ll leave for another guide. There are numerous other considerations that go into FI, such as fueling, tuning, and cooling, which are too numerous to go into detail.
1) Modifications to the BRZ Performance Cold Air Intake
The FA20 engine’s stock intake system isn’t always optimized for airflow. It is, on the other hand, rather restrictive and may thus limit your performance potential. Upgraded intakes, also known as cold air intakes, can increase air flow by up to 50%. While an intake isn’t required to be the first mod you install, we do recommend installing one at some point because more power necessitates more air.
There are several options for BRZ intake upgrades. You can start with a simple K&N or aFe drop-in filter. This will result in some minor performance gains and airflow increases. The advantage is that it is the cheapest option and keeps your stock intake system intact if warranty is an issue.
The second and third options, which we recommend, are full intake systems. To draw in cooler air, the Perrin system will relocate the air filter ahead of the radiator, essentially right at the front of the bumper. The Mishimoto, Injen, and aFe Takeda systems retain the stock intake location but use a heat shield or enclosed box to keep hot engine air out.
Overall, the performance advantages of full intake systems are nearly identical from one brand to the next. Some claim slightly higher horsepower gains than others, but the small difference isn’t significant because each car dynoes differently.
Improved MAF Piping
The stock BRZ intake system is technically divided into two sections. The intake box and associated piping, which connects to the MAF sensor piping, are the first. The MAF sensor piping, which connects the first section to the intake manifold, is the second piece.
Replacing the MAF sensor piping with upgraded piping can result in a 5whp boost. While it adds about $150 to the overall cost, it’s a worthwhile upgrade to get more out of the intake system.
We recommend the following two options:
- Performance Inlet Hose by Perrin
- Induction Hose Mishimoto
Advantages of FA20 Performance Intake
- Gains of approximately +10whp and +8wtq
- Upgraded MAF piping results in an additional +5whp gain.
- Cooler intake air temperatures
- Increase in airflow of 50% or more
- Under acceleration, there is a cool intake noise.
Best Subaru BRZ Intake Systems
As we mentioned above, all of these systems pretty much produce the same amount of power gains and benefits. However, depending on your budget or goals, we will offer our recommendations for the best setup options.
- Mishimoto BRZ FRS GT86 Intake is the best bang for your buck.
- Perrin Performance Intake + Perrin Inlet Hose = Best Relocated Intake
- K&N Drop-in Filter is the best drop-in filter.
Mishimoto wins best value because it includes the intake system as well as the inlet hose for $330. The inlet hose for the Perrin system must be purchased separately, making this system about $50 more expensive than the Mishimoto.
However, if you want the filter relocated into the bumper for slightly cooler intake air temperatures, the extra cost may be worth it for you.
2) Performance Headers for the FA20
As previously stated, the torque dip is caused in part by the exhaust manifold design. Therefore a great mod is upgrading the exhaust manifold with a set of performance headers. Because air from the exhaust ports is funneled into one chamber, exhaust manifolds generate back pressure. Headers eliminate this restriction by providing each exhaust port with its own piping, which then connects right before the catalytic converter.
The exhaust system on the BRZ is installed in the following order: headers, over-pipe, front-pipe (which houses the catalytic converter), mid-pipe, and muffler. The FA20 engines come standard with unequal length headers, which is a common Subaru engine feature. This means that the piping for two of the exhaust ports is longer than the piping for the other two.
At the end of the day, you have two choices: equal length headers or unequal length headers. Both produce the same power levels, so which you choose is entirely up to you. If you want to learn more about the differences between UEL and EL headers, click here.
For reference, here’s a photo of the OEM header versus a set of performance headers:
Advantages of FA20 Performance Headers
- Gains of 10whp and 8wtq
- Exhaust note is a little deeper now.
- Backpressure has been reduced.
- Enhanced throttle response
- Partially corrects the 4k rpm dip
Best BRZ/FRS/GT86 Headers
Because the power gains of equal and unequal length on a naturally aspirated engine are nearly zero, the two most important factors are price and sound.
- BLOX Motorsports
Low Quality on a Shoestring Budget
3) Catback Exhaust System for BRZ/FRS/GT86
Before we get to the cat-back section of the exhaust, there are two other components that can be upgraded. Two components that can be upgraded for more power are the over-pipe and the front-pipe. While removing the cat in the front-pipe or going with a high-flow option would normally result in more power, this isn’t always the case with the FA20.
According to dyno testing, a catless front-pipe added only 5whp over the stock pipe. That means a high-flow catted option would probably make around 2whp, with the overpipe adding another 1-2whp. Overall, we believe that the power gains here aren’t worth the cost.
So let’s talk about cat-back systems. Power gains of around 8whp are shown on dyno charts for a cat-back exhaust on the BRZ. This is quite good for a naturally aspirated engine, and you also get the advantages of more attractive exhaust tips and louder exhaust notes.
Advantages of FA20 Catback Exhaust
- Approximately 8whp and 5wtq
- With beefier exhaust tips, the car looks a lot better from the back.
- Louder and deeper exhaust tone; on a stock system, you can’t even hear the exhaust.
- Increased exhaust flow
The Best Subaru BRZ Exhaust System
Again, the most important factors here will be price and sound. Almost all of these brands will have power gains in the same ballpark. There are literally 50+ options, so I’ll go over some of the more popular ones. There are some premium systems that can cost up to $1,500, but we recommend sticking with something $1,000 or less because the extra money isn’t worth it in terms of performance.
Amazon’s Low-Cost Options
- Tsudo Se – this has a muffler delete, making it louder.
Better Brands without Spending a Fortune
- Agency Power
4) Flash Tune FA20
To be fair, the power figures for the mods listed above are probably inaccurate until you add a tune. Adding a tune in conjunction with these other modifications is where the FA20 engine’s power gains are realized.
Furthermore, a flash tune is the most important component of removing the torque dip, so it is a must-have. We only have this at number four on our list because the power gains from a tune are amplified when combined with the above three mods, so it’s always a good idea to combine them.
Flash tunes plug into the ECU and reprogram various components such as ignition timing, air-to-fuel ratios, and other variables to boost power. Custom tunes compiled through dyno tuning or data logging can also be run on flash tuning devices.
Performance Advantages of BRZ Flash Tuning
- +8-12whp and wtq gains on pump gas (up to 25whp and wtq with below E85 mod)
- The ability to switch tunes on and off on the fly, change maps, and so on.
- Supports custom tuning
- Torque dip is eliminated (when paired with headers)
- Power band that is more consistent
- Improved throttle response
Options for FA20 Flash Tuning
Flash tuners typically include pre-built maps that can be “flashed” on and off. Depending on the mods you have, the included maps usually include a few performance options, an economy or mpg map, and a few others. To connect to and overwrite the ECU, they either plug into the OBDII port or use a Bluetooth connection.
They also have a slew of other features, such as engine code diagnostics, data logging, monitoring, and so on. There are also options such as launch control, rev limiting, downshift blipping, and so on.
There are only two flash tuning options for the FA20.
OpenFlash Tablet Vishnu
Unlike the EcuTek tune below, the Vishnu OpenFlash option doesn’t require you to purchase the software from a specific tuner. The Vishnu tuner is truly plug-and-play, and it comes preloaded with a few performance maps for those who aren’t quite ready to dive into custom tuning. It has all of the same features and options that are described below.
This is our preferred option at $500 because it is slightly less expensive and comes with preloaded tunes without tying your horse to a specific tuner.
EcuTek tunes aren’t as simple to install as a plug-and-play option. They require you to buy hardware as well as a software license from an authorized tuner. Each of these authorized tuner programs either maps into the EcuTek hardware or provides custom tuning in conjunction with the purchase of the hardware and software. They also offer various packages based on performance goals, current mods, and so on.
Here are some well-known and popular tuners where you can purchase EcuTek tunes:
- Delectable Tuning
- FT Rate
- Garage Counterspace
5) Subaru BRZ E85 Fueling Modifications
In addition to the power gains from the other mods listed, a tune will add around 10whp on pump gas. However, when combined with BRZ E85 fueling mods, a tune can add up to 25whp, implying that E85 fueling alone can add another 15whp.
The benefit of not having a turbo is that these cars received both port and direct fuel injection. Because these vehicles have both fueling options, they can easily run full E85 fuel. Because the turbo version of this engine only uses direct injection, it requires significant fueling upgrades to run on 100% E85.
E85 is almost entirely alcohol. As a result, it has a 108 octane rating. This means it has a lot more power than regular 91 octane pump gas. We won’t go into specifics, but higher octane fuel allows for more ignition advance, which is where power gains from tunes typically come from.
While it isn’t as simple as simply putting E85 in the tank, all you need to run full E85 is a tune. Here’s a tutorial for running full E85 on Vishnu OpenFlash.
E85 Performance Advantages
- +15whp and torque gains, totaling about 25whp/wtq with the tune
- It is less expensive than gasoline.
- Once you have a tune, this is a completely free mod.
Summary of BRZ Mods: +50whp for $2,000
You can add 50whp to your BRZ, FRS, or GT86 for around $2,000 and eliminate the torque drop in the power curve.
Headers and a tune are our two favorite mods on the list. If you’re only going to make a few changes, we recommend starting with those two. While an intake and cat-back exhaust system still provide significant power gains, the smoothing of the power curve is the primary benefit of the other two.
A stock BRZ will dyno at 160-170whp depending on compression. Adding these mods raises the power levels to 210-220whp, making this small car much faster. We didn’t mention it before, but the headers and cat-back exhaust system can help you lose about 20 pounds. While this isn’t much, it does make the mods more worthwhile.
High-flow cats or catless pipes, as well as overpipe upgrades, are two BRZ mods we didn’t go into detail about. Adding these extra parts can result in an additional 5-8whp. However, the majority of those gains come from the cat pipe which can be expensive to upgrade unless you choose the catless (illegal) route. Overall, you can’t beat an extra 50whp on a 2,700lb car for under $2,000.