Subaru WRX (FA20DIT) Turbo

Subaru WRX (FA20DIT) Turbo Upgrade Guide

2015-2021 Subaru WRX (VA) is an excellent current tuner vehicle. If you’re willing to spend a little more money, you can get a lot more performance out of it. The factory-installed FA20DIT engine in the WRX is a 2-liter, direct-injection flat-four rated at 268 horsepower and 258 pound-to-pound torque. A six-speed manual transmission is a rarity in today’s automobiles, and it’s well-respected.

The WRX has just undergone intercooler and downpipe/j-pipe improvements, and now it’s time for turbos to take center stage. Turbo upgrades for the WRX are ideal for people who are trying to increase their WRX’s power and performance capabilities. In this guide, we’ll discuss all things turbo on your WRX, and then we’ll look at the top turbo kits available on the market.

Can the FA20 Handle a Turbo Upgrade?

Turbocharger Garrett GT2259 journal bearing, twin-scroll fitted in the 2015-2021 Subaru WRX. It has a 50.3 mm compressor wheel, an oil cooler, and an internal waste gate. The GT2259 can produce up to 375hp with complete bolt-on upgrades and E-85 fuelling before it begins to lose steam. After 350 horsepower, it runs out of pump gas.

It’s a terrific idea to upgrade the turbo on the FA20, and it’s not just for people who want to increase peak horsepower. To get the most out of the turbo, it is best to choose a turbo that is somewhat larger than stock. The default turbo works well in the middle of the rev range, but struggles to maintain airflow at higher speeds.

It’s important to know how much power you can get out of the WRX turbo before the internals break. The connecting rods have traditionally been the engine’s Achilles’ heel, although the block and pistons are generally trustworthy. Others have reported operating at 350whp for more than 50,000 miles with no problems, despite the claims of many that they fail at this power level.

There’s no way to know just how much stress the FA20DIT can withstand before it fails. If you drive it gently, you should be able to regularly get 350 whp. Above that, you may want to consider getting new connecting rods, head studs, or a custom-built block.

Can the FA20 Handle a Turbo Upgrade?

The factory installed turbo on the 2015-2021 Subaru WRX is a Garrett GT2259 journal bearing, twin-scroll turbo. It is oil cooled with a 50.3 mm compressor wheel and is internally wastegated. With full bolt-on mods and E-85 fueling, the GT2259 can make approximately 375hp before it starts to fall off and run out of steam. On just pump gas it runs out after 350hp.

Upgrading the turbo on the FA20 is a great idea, and not just for those looking to make huge peak power. Putting in a slightly bigger turbo allows for a larger powerband that does not fall off past 5800rpms. The stock turbo is great at delivering in the mid-range, but it struggles to keep breathing in the upper rpms.

The real question when upgrading the WRX’s turbo is how much power you can make before the internals start to fail. The block and pistons are pretty reliable on the engine, and the weak point has always been the connecting rods. Many people will say they fail at 350whp, but others have reported running at those levels for 50,000 miles plus with no issues.

In reality, there is no definite answer about how much the FA20DIT can take before the internals give out. Generally, people can expect to run 350whp pretty consistently with moderate driving. Anything above that it is probably a good idea to upgrade your connecting rods and look into head studs and maybe a built block.

Twin-Scroll Turbo Basics

In addition to the GT2259 turbo, all of the WRX turbo upgrade kits use twin-scroll turbines (VA). The inefficiencies of a typical turbo are reduced by a twin-scroll turbo’s improved efficiency. Two-scroll exhaust systems distribute exhaust pulses evenly across the two exhaust pipes. Exhaust gas energy is more efficiently delivered to the turbine as a result of greater scavenging and efficiency. Reduced cylinder pressure and temperature allow for higher turbine efficiency and reduced EGTs.

With a twin-scroll system, boost normally kicks in earlier, but it can still provide more peak power. Stock, the WRX’s turbocharger delivers 16 psi of boost pressure, but it can provide up to 22 psi for limited periods of time during overboost. Tuners typically raise the OEM turbo’s PSI by 3-4 PSI when working with bigger turbos, however this is not always the case.

How much power can I make with a turbo upgrade on my WRX?

A turbo upgrade for the WRX can result in moderate to enormous increases, depending on the turbo’s boost and cfm output. On pump gas, smaller turbos may easily produce 350-400whp, and the power ladder can be extended all the way to quad-digit designs using ethanol.

However, the benefit of a modern turbo isn’t only the amount of power you can produce at full throttle. A bigger turbo will improve the whole powerband, although it will be most noticeable in the mid-range. A turbocharger with a greater diameter will cause a change in powerband rightward as it increases in size. To get the most out of the biggest turbos, you’ll have to sacrifice some power in the lower and middle ranges.

Rally and autocross drivers will emphasize power in the early and mid-range of the engine’s rev range, whilst drag racers will go for the FA20’s largest turbo available. There is a turbo boost to fit your needs, no matter what you’re building or what your ambitions are.

Precursors to FA20 Turbo Upgrades

Ensure your WRX will run safely and reliably first before looking at turbo upgrades. Intake/exhaust, cooling, fuelling, boost control, and tune are all important considerations when making an upgrade. The first thing you should consider for your WRX is not a turbocharger. Prior to going turbo on the Rex, you’ll want and need these supporting modifications.

Intake/Exhaust

Your WRX’s exhaust and intake system must be modified before installing a larger turbocharger. It is recommended that you use a complete turbo back exhaust system with at least 2.5-inch pipe, if not 3.0-inch. Take a look at our guide to WRX downpipes/j-pipes and see what works best for your vehicle. A bigger turbo can rapidly choke out any benefits if the standard exhaust isn’t able to handle the additional flow.

In addition, you’ll require a new intake. You’ll need a more efficient intake system if you’re going to make more than 350 horsepower with a turbocharger. Before purchasing an intake, be sure to check the compatibility of the turbo kit with the intake.

Cooling

Before installing a bigger turbocharger on your WRX, you must first upgrade your intercooler. An aftermarket intercooler is required for any increase in power above what can be handled by the factory unit. Find out which WRX intercooler improvement is best for your project car in our guide on WRX intercooler upgrades. The charge pipe that links the intercooler to the turbo should also be upgraded. Make sure your intercooler is compatible with the new charge pipe before you buy it, as the standard one is somewhat limiting beyond 350 horsepower.

If you live in a hot region like Arizona or Texas, you may want to consider replacing your radiator as well. Because larger engines create more heat while running at higher RPMs for longer periods, high coolant temperatures can become a concern after repeated runs.

Fueling

Direct injection fuelling is standard on the FA20DIT, thus upgrading the injectors isn’t normally necessary. No need to modify the high-pressure fuel pump (hpfp). In-tank gasoline pumps greater than the normal Deatschwerks 65c or 300c are highly recommended.

Users who want to get the most out of their turbo boost should carefully consider using E-85 flex fuel on their WRX. Keep in mind, though, that the majority of tuners can only handle an E-60 blend. The hpfp begins to clog with greater amounts of ethanol, resulting in a slew of headaches.

However, there are still enormous advantages to be had by using E-60 instead of regular gasoline. Ethanol is a terrific long-term investment for engine longevity since it allows tuners to create considerably safer power.

Boost Control

Another critical component of any turbo upgrade is boosting control. A 3-port electronic system is almost universally required by tuners to update their clients’ standard two port systems to electronic. In comparison to the original system, the Electronic Boost Control System with three ports provides far more precise and accurate boost control. If you’re utilizing the stock turbo, most tuners recommend it, even if you’re upgrading it.

Tuning

In the end, tuning is perhaps the most crucial component of any WRX turbo boost setup. Before putting a turbo kit on your FA20, you must need a tuning solution. A transaction with a tuner should ideally be arranged ahead of time, not after your new turbo is fitted. Changing turbos may necessitate special modifications, so check with your tuner ahead of time.

In addition to E-tuning, Subarus may also be tuned on the dyno in person. The Cobb Accessport is one of the most widely used and well-known tuner interfaces available today. Don’t be afraid to ask for help from a professional tuner who is eager to work with you.

To protect the safety of your vehicle, it’s critical that you continue data logging even after your tune is complete. Monitoring your air-to-fuel ratio, knock sensors, and boost is critical to the health of your vehicle.

Best Subaru WRX Turbo Kits

Let’s have a look at the best turbo kits for the FA20 WRX now that we know what it takes for a safe and reliable turbo installation. Among the various turbo kits on the market today, these are our top picks for the best of the best. It’s a terrific combination of performance, accuracy, quality, and cost.

1) Extreme Turbo Systems 2015+ WRX Turbo Kits

ETS’s 2015-2021 Subaru WRX Turbo Kit is the first item on our list. As a pioneer in the field, the ETS Kit has shown to be a reliable and long-lasting investment. In addition to the six size choices available for the ETS turbo kit, Precision Turbos makes all of them. The 5858, 5558 Gen 2, 5862 Gen 2, 6062 Gen 2, 6266 Gen 2, and 6466 Gen 2 turbo options are available.

All ETS kits come with two dump tubes, two wastegates, and headers and a downpipe as standard equipment. When combined with bigger PT turbos, correct modifications and Ethanol fuelling, this kit is capable of producing as much as 1200whp on an FA20.

Kits like this one are the most costly, but they come with everything you need to install a turbo, from the downpipe and headers to the turbine. However, it is the most tried and tested and, depending on the turbo used, may provide the maximum power.

2) Forced Performance FA20DIT Turbo Kits

A pair of Forced Performance turbos are the next item on our agenda. In terms of turbos for both WRXs and Evos, FP has established themselves as a reliable manufacturer, and their FA20 range does not disappoint. You may choose between an FP Blues option with either an internal or external wastegate and an optional coated turbine housing.

The CHRA is what separates the two of them. The Xona Rotor Ball Bearing is in one and the journal bearing is in the other. While the Xona Rotor costs $1,100 more, it improves longevity and cuts down on spool time. On E-85, both turbos generate 57lb/min and 475whp. The power curve of this turbo was particularly optimized for the FA20.

3) SteamSpeed FA20 Turbo Kits

The WRX may be fitted with one of two turbo kits from SteamSpeed. There are two models, each with their own unique ball bearing turbo, the GEN2 67R+ in one and the GEN2 71R in the other. For Stage 2 kits, these turbos are bolt-on replacements for the stock turbos.

If you’re looking to make 350whp-400whp on pump gas or 425whp on E85, you’ll need the 67R+. The 67R turbo is combined with the ball bearings of the 71R turbo. With E-85 fuelling, the 71R can produce 500whp and flow an astounding 59lbs/min. As a straight replacement for the stock position as well as most “Stage 2” kits, this part is also compatible.

Even while the SteamSpeeds aren’t as durable or powerful as the FP or ETS kits, they’re still a good value for the money. The FP and ETS kits are more expensive, but they have been shown to provide good power.

4) SoCal Performance V4 GT2259 Upgrade 

There is no turbo kit on this list, but a turbo upgrade for the factory GT2259 turbo, which is included. Even though SoCal porting is a new entrant to the WRX market, they’ve already established a great track record. If you don’t want to buy a new turbo, SoCal offers to enhance the compressor wheel and turbine shaft of the original turbo. Additionally, the whole package includes machining, re-contouring, clipping, rebuilding, and full porting and polishing of the OEM turbo.

Your FA20DIT stock turbo is sent to them, and they do the improvements before returning it to you. Finally, they’ve come up with their best-flowing compressor wheel design to date. In addition, it maintains all of the standard housings for perfect OEM fitment. With complete bolt-ons and E-85 fuelling, users may generate as much as 560whp on the standard turbo.

Remember that the factory turbo will not be able to dissipate heat to the extent that an aftermarket turbo will. The result will be an increase in EGTs as well as a decrease in lifespan. While this is the most expensive choice, it is also one of the most cost-effective ones.

FA20 WRX Turbo Upgrade Summary

If you want to boost your WRX’s powerband and peak performance, you should consider upgrading the turbo. When it comes to installing a new turbo in your WRX, the possibilities are endless with the right modifications (VA). From modest (350-400whp) to some of the world’s quickest automobiles, there are a variety of alternatives available (1200whp).

There are a number of supporting modifications that must be installed on your FA20DIT in order to improve your turbo. If you’re serious about boosting your horsepower, you should definitely upgrade your connecting rods and have a custom-built block.

All of the turbo kits we recommend are based on reliability, performance, and cost considerations. The ETS exhaust system is the most costly, but it is also the most well-tested and incorporates additional exhaust modifications. It’s no secret that FP Blue turbos are the gold standard for WRX and Evo enthusiasts, and the FA20 range is no exception. SteamSpeed is an excellent low-cost solution that may achieve impressive results, but its long-term viability remains a question mark. SoCal porting’s V4 upgrade for the OEM turbo is another nice choice for people that want to keep their factory hardware but yet receive a good power boost.

Since all of the kits are made to fit all WRX (VA) models, the only decision to be made here is what size turbo to choose. There is a limit to how much power can be generated by a turbocharger, and that limit is reached when the turbo is too large. It’s all up to you and what’s most important to you as a builder.

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