The 5 Best Subaru BRZ, FRS, GT86 Performance Mods

The Subaru BRZ, Scion FR-S, and Toyota 86 are built on the same chassis and powered by Subaru’s FA20 engine, a 2.0L flat-four. While a turbocharged FA20 engine was produced, the BRZ and its brethren are powered by the naturally aspirated FA20D. In 2021, the second generation BRZ and GT86 was released which included an updated exterior look and also the inclusion of a large 2.4L engine.

The 2.0L BRZ produced 197-205hp and 151-156lb-ft. of torque. While these numbers might not seem very appealing, the approx. 2,700lb curb weight of these cars makes them a joy to drive. They are similar to a Miata in the sense that you would never call them fast but instead say they are very quick. Their lightweight, low-center of gravity makes for excellent handling a lot of fun around the corners.

However, if their 7.6 second 0-62mph time doesn’t excite you, there are a handful of simple BRZ performance mods that can be bolted-on to give these small engines a little more oomph. This guide will cover the 5 best bolt-on mods for the BRZ, FRS, and GT86.

The FA20 engine powering the BRZ, FRS, and GT86 is capable of adding about 50whp with a few thousand dollars of mods.

This mod guide will be tailored to the first gen BRZ’s. However, while fitment for the second gen models will be different, the overall gist of the guide is the same. Despite a larger 2.4L engine, the FA24 used in the 2021+ BRZ and GT86 is also naturally aspirated and therefore the recommended mods for these engines will be the same as the FA20 BRZ and GT86.

Looking for suspension and handling mods? Check out our BRZ, FRS, GT86 Coilover Upgrade Guide.

BRZ 4,000 RPM Power Drop

Before we dig into the mods in detail one thing we need to discuss is the FA20D’s natural power drop. The natural power band for a stock FA20 has a dreadful torque drop from the 3,500 to 4,000 rpm range. This can make your car feel very sluggish under heavy acceleration.

If we look at the below graph, you’ll notice torque begins dropping around the 3,250rpm mark and hits its low point at 4,000rpms. From there it begins climbing back upwards where it fully recovers around the 4,500rpm mark.

The cause of the torque drop is predominantly caused by the design of the OEM exhaust manifold/headers. Therefore, we can fortunately smooth this dip out through the addition of some performance headers and a proper flash tune or custom tune. Note that just headers alone won’t fix the issue, you’ll need to combo the headers with a tune.

Best BRZ Performance Mods

Some of the best BRZ engine upgrades include:

• Intake
• Headers
• Catback Exhaust
• Tune
• E85 Fuel

You’ll notice we left off some major mods such as a turbochargers or superchargers. This guide is mostly focused on simple bolt-on modifications to yield some nice and affordable power gains. To produce serious power with your BRZ you will need to look into forced induction, but we’ll leave that for another guide. There are a lot of other considerations that go into FI such as fueling, tuning, and cooling which is a lot of detail to get into.

We’ll put a link here to our BRZ Turbo Guide once we have it written.

1) BRZ Performance Cold Air Intake Mods

The stock intake system on the FA20 engine isn’t necessarily optimized for airflow. It is instead rather restrictive and can therefore limit your performance potential. Upgraded intakes, also commonly called cold air intakes, will increase air flow by upwards of 50%. While an intake doesn’t need to be the first mod you add, we do recommend adding one at some point as more power requires more air.

There are a few different options for BRZ intake upgrades. First, you can opt for a simple K&N or aFe drop-in filter. This will provide some very minor performance gains and small increases to airflow. The benefit being it is the cheapest option and keeps your stock intake system intact in case you are concerned about warranty.

The second and third options are full intake systems, which is what we recommend. The Perrin system will relocate the air filter ahead of the radiator, essentially right at the front of the bumper, to draw in cooler air. The Mishimoto, Injen and aFe Takeda systems use the stock intake location but instead either use a heat shield or enclosed box to prevent hot engine air from being sucked in.

Overall, the performance benefits of full intake systems are virtually the same from brand to brand. Some claim slightly higher horsepower gains than others but the small variance isn’t a big factor as all cars dyno differently.

Upgraded MAF Piping

The stock BRZ intake system technically has two different sections. First one is the intake box and associated piping which connects to the MAF sensor piping. The second piece is the MAF sensor piping which is between the first section and the intake manifold.

Replacing the MAF sensor piping with an upgraded piping can add an additional 5whp. While it does add about $150 to the total cost, it’s a good upgrade to get a bit more out of the intake system.

There are two options that we recommend here:

• Perrin Performance Inlet Hose
• Mishimoto Induction Hose

FA20 Performance Intake Benefits

• Approx. +10whp and +8wtq gains
• Extra +5whp gains with upgraded MAF piping
• Slightly colder intake air temps
• 50%+ increase in airflow
• Cool intake noise under acceleration

Best BRZ Intake Systems

As we mentioned above, all of these systems pretty much produce the same amount of power gains and benefits. However, we’ll provide our opinions on what the best setup options are depending on your budget or goals.

• Best Bang-for-the Buck: Mishimoto BRZ FRS GT86 Intake
• Best Relocated Intake: Perrin Performance Intake + Perrin Inlet Hose
• Best Drop-in Filter: K&N Drop-in Filter

Mishimoto wins best bang-for-the-buck since for ~$330 it includes the intake system plus the inlet hose. For the Perrin system, the inlet hose needs to be purchased separately which makes this system cost about $50 more than Mishimoto.

However, the extra cost could be worth it for you if you want the filter relocated into the bumper for slightly colder intake air temps.

2) FA20 Performance Headers

As we discussed above, the torque dip is caused in part by the design of the exhaust manifold. Therefore a great mod is upgrading the exhaust manifold with a set of performance headers. Exhaust manifolds create back pressure since air from the exhaust ports is funneled into one chamber. Headers remove that restriction by giving each exhaust port its own piping, which then meet together right before the catalytic converter.

On the BRZ’s the exhaust system goes in this order: headers, over-pipe, front-pipe which houses the catalytic convert, mid-pipe, and then muffler. The FA20 engines have unequal length headers from the factory, a common Subaru engine trait. This means that two of the exhaust ports have longer piping than the other two.

At the end of the day your two options are equal length or unequal length headers. Both make the same power levels so whichever you choose is up to you, here is a link if you want to check out the difference between UEL and EL headers.

Here is a picture of the OEM header compared to a set of performance headers, for reference:

FA20 Performance Headers Benefits

• ~10whp and ~8wtq gains
• Slightly deeper exhaust note
• Reduced backpressure
• Improved throttle response
• Partially fixes 4k rpm dip

Best BRZ/FRS/GT86 Headers

Since the power gains of equal length and unequal length on a naturally aspirated engine are virtually zero, the two biggest factors are price and sound.

• Budget Friendly Options
  • MAPerformance
  • Tomei
  • HKS
  • JDL
  • aFe
• Break-the-Bank
  • BLOX Racing
  • Beatrush
• Super Budget: Lower Quality
  • Skunk2

3) BRZ/FRS/GT86 Catback Exhaust System

Before we get into catbacks, there are two other components that can be upgraded before we get to the cat-back part of the exhaust. The over-pipe and the front-pipe are two components which can be upgraded for more power. While removing the cat in the front-pipe or opting for a high-flow option would usually add some solid power, it isn’t necessarily the case on the FA20.

Per dyno tuning a catless front-pipe only added 5whp over the stock pipe. That means a high-flow catted option would probably make like 2whp, and you can probably expect another 1-2whp from the overpipe. Overall, the power gains here just aren’t worth the cost in our opinion.

So onto cat-back systems. Dyno charts show power gains around 8whp for a cat-back exhaust on the BRZ. This is quite good for a naturally aspirated engine, plus you get the benefits of the better looking exhaust tips and louder exhaust notes.

FA20 Catback Exhaust Benefits

• Approx. 8whp and 5wtq
• Car looks a lot better from the rear with beefier exhaust tips
• Louder and deeper exhaust tone, you can’t even hear the exhaust on a stock system
• Improved exhaust flow

Best BRZ Exhaust System

Again, the biggest factors here are going to be price and sound. The power gains are going to be in the same ballpark for virtually all of these brands. There are honestly like 50+ options so I will layout some of the more popular choices. There are some premium systems than can get upwards of $1,500 but we would recommend sticking to something $1,000 or under just since the extra $ isn’t worth it from a performance perspective.

• Cheap Amazon Options
  • Spec-D
  • Tsudo Se – this has a muffler delete so it will be louder
• Better Brands without Breaking the Bank
  • Perrin
  • MAPerformance
  • GReddy
  • Agency Power
  • Tomei
  • Apexi
  • HKS
  • Invidia

4) FA20 Flash Tune

To be fair, the power numbers quoted for the mods above probably aren’t accurate until you’ve added a tune. Adding a tune in conjunction with these other modifications is where you really achieve the power gains out of the FA20 engine.

Additionally, a flash tune is the most important component of eliminating the torque dip so it’s a must have. We only have this at number 4 on our list because the power gains from a tune are amplified when you have the above 3 mods so it’s always great to combo them together.

Flash tunes connect into the ECU and essentially reprogram various components like ignition timing, air-to-fuel ratios, and other variables to increase power. Flash tuning devices can also run custom tunes that were compiled via dyno tuning or data logging.

BRZ Flash Tune Performance Benefits

• +8-12whp and wtq gains on pump gas (up to 25whp and wtq with below E85 mod)
• Plug-and-play
• Ability to turn tunes on and off on the fly, change maps, etc.
• Supports custom tuning
• Removes torque dip (when paired with headers)
• Smoother power band
• Better throttle response

FA20 Flash Tuning Options

Flash tuners usually come with pre-built maps that you can “flash” on and off. The included maps usually include a few performance options depending on the mods you have, an economy or mpg map, and a handful of others. They either plug into the OBDII port or use a Bluetooth connection to connect to and overwrite the ECU.

Additionally, they have numerous other features such as engine code diagnostics, data logging, monitoring, and so on. Furthermore you have options like launch control, rev limiting, downshift blipping, and so on.

For the FA20 there are really only two flash tuning options.

Vishnu OpenFlash Tablet

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 comes preloaded with a handful of performance maps for those not quite looking to get into custom tuning. It offers all the same features and options as described below.

At $500 this is our preferred option as it is slightly less costly and comes with preloaded tunes without having to hitch your horse to one specific tuner.

EcuTek

EcuTek tunes aren’t quite as simple as a plug-and-play option. They require you to purchase hardware and a software license from an approved tuner. Each of these approved tuners programs maps into the EcuTek hardware or offers custom tuning in conjunction with the purchase of the hardware and software. They also have different packages based on performance goals, current mods, etc.

Here are some prominent and popular tuners that you can buy EcuTek tunes from:

• Delicious Tuning
• FT Speed
• Counter Space Garage

5) Subaru BRZ E85 Fueling Mods

A tune will add around 10whp on pump gas, in addition to the power gains from the other mods listed. However, when a tune is used in conjunction with BRZ E85 fueling mods it can add up to 25whp, meaning that E85 fueling alone can get you another 15whp.

The fortunate part of not having a turbo in these cars is that they received both port and direct fuel injection. Having both fueling capabilities means that these cars can easily run full E85 fuel relatively easily. The turbo version of this engine only uses direct injection which means it needs a lot more fueling upgrades to run 100% E85.

E85 is pretty much pure alcohol. Because of this it has a 108 octane rating. This means that it produces a lot more power than your typical 91 octane pump gas. We won’t go into details but the benefit of higher octane fuel is that it allows for more ignition advance which is where power gains from tunes usually come from.

While it isn’t as simple as purely putting E85 in the tank, the only thing you need to run full E85 is a tune. Here is a guide on how to run full E85 on Vishnu OpenFlash.

E85 Performance Benefits

• +15whp and torque gains, about 25whp/wtq in total with the tune
• It’s cheaper than gas
• Completely free mod once you have a tune

BRZ Mods Summary: +50whp for $2,000

For about $2,000 you can add 50whp to your BRZ, FRS, or GT86 and eliminate the torque drop in the power curve.

Our two favorite mods on the list are headers and a tune. If you are only going to make a few mods, we suggest going with those two. While an intake and cat-back exhaust system still provide solid power gains, the biggest benefit of the other two is the smoothing of the power curve.

A stock BRZ is going to dyno around 160-170whp depending on compression. Adding these mods can bring those power levels to 210-220whp which makes this small car a lot faster. We didn’t mention this earlier but you can also shave about 20lbs. off of the car with the headers and cat-back exhaust system. While this isn’t a ton, it makes the mods even more worthwhile.

A few BRZ mods that we didn’t mention in detail are high-flow cats or catless pipes, and overpipe upgrades. Adding these additional parts can bring you an extra 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, especially for just $2k.