Building the Perfect VB WRX: A Balanced Approach

Building the Perfect VB WRX: A Balanced Approach

The Subaru WRX (chassis code VB) is a versatile platform that lends itself to a variety of builds, from a refined daily driver to a focused track machine. This guide outlines how to create a fast and fun street car that excels in light track use while balancing practicality and reliability.

Step 1: Define the Goal

Before modifying your WRX, establish a clear objective for your build. This clarity will guide your choices and help you avoid unnecessary spending. In this case, we aim to build a high-performance street car that’s capable of handling occasional track sessions with ease.

Step 2: Start with a Tune

A proper tune is the single most impactful modification for the VB WRX. Start with a Cobb Tuning Accessport, an essential tool that provides access to off-the-shelf (OTS) maps and the option for custom tuning. While the Cobb OTS map is a good baseline, significant gains in power, throttle response, and efficiency are unlocked with a custom tune.

Even on a completely stock WRX, a custom tune transforms the car, delivering a massive improvement in drivability and performance. No single part—or even a combination of parts—offers a similar bang for your buck.

Step 3: Improve Airflow

After tuning, addressing airflow is the next step in unlocking the WRX’s potential.

1. Intake System:
   There are numerous aftermarket intake options, but the Extreme Turbo Systems (ETS) Cold Air Intake stands out in extensive dyno testing. It delivers consistent power gains, especially when the internal reducer is removed. This modification requires a tune calibrated for the intake. For convenience, consider an e-tune designed specifically for the ETS system or opt for a custom tune to maximize performance.
2. Turbo Inlet:
   The factory turbo inlet pipe is restrictive, limiting airflow and turbo efficiency. Replace it with the Perrin Silicone Turbo Inlet, tailored to work seamlessly with the ETS intake. This upgrade improves turbo spool, delivering stronger low-end torque and enhanced top-end power.
3. Intercooler Options:
   The stock top-mount intercooler (TMIC) is surprisingly effective for most street and light track applications. Its plastic end tanks and tapered charge pipes excel at minimizing heat soak, directing heat transfer where it’s most effective. If an upgrade is desired, opt for a front-mount intercooler (FMIC) from brands like Cobb, Perrin, or ETS. Smaller FMIC cores minimize transient lag while avoiding heat soak from engine bay temperatures. Keep in mind that excessively large FMICs can increase turbo lag due to additional piping volume.
4. Headers:
   Unless you plan to use high-octane or ethanol fuels, aftermarket headers are unnecessary. Unequal-length headers (UEL) may appeal to enthusiasts chasing the Subaru rumble but tend to be less durable. If headers are part of your build, the ETS headers are durable and reliable.
5. Turbocharger Upgrades:
   Turbo upgrades offer a significant performance boost, particularly for top-end power, often at the expense of some low-end torque. This tradeoff can be beneficial, as it reduces stress on torque-sensitive components like the clutch and transmission. The factory turbocharger is already highly capable, but for those seeking more:
• The Blouch 5356 is an excellent choice for maintaining stock-like spool characteristics while adding top-end power.
• For greater performance potential, the ETS Quickspool kits with Garrett G25-600 or G30-700 turbos provide impressive gains. These options, however, may be overkill for street-focused builds. Carefully consider your goals before committing to a larger turbo setup.
6. Exhaust and J-Pipes:
   Aftermarket cat-back exhausts primarily enhance sound and aesthetics, providing minimal performance gains at this stage. Choose one based on your personal preferences.
   J-pipes are a contentious topic due to emissions regulations. While aftermarket options exist, none currently meet EPA/CARB standards in all 50 states. Some enthusiasts opt to modify the rear catalytic converter only, preserving the front catalyst to reduce the likelihood of emissions-related issues.

Step 4: Suspension and Braking

1. Brakes:
   The factory brakes are adequate for casual driving but lack the performance needed for repeated hard braking.
• For a cost-effective upgrade, start with performance-oriented brake pads, such as Hawk HPS. These pads offer excellent initial bite and improved thermal resistance, making them suitable for autocross and short track sessions.
• For more intensive track use, a full big brake kit (BBK) from AP Racing or StopTech is recommended. AP Racing is a standout option, offering tailored solutions based on your specific needs.
2. Suspension:
   The factory suspension strikes a good balance for street use, but upgrading can enhance handling and aesthetics:
• Lowering Springs: High-quality performance springs designed for the factory dampers provide improved handling without sacrificing ride comfort.
• Coilovers: If maximum grip and adjustability are your goals, invest in a premium coilover system. Be aware that coilovers require more maintenance and may compromise ride quality for daily use.

Step 5: Drivetrain Enhancements

1. Clutch:
   As power levels rise, the stock clutch can become a weak point. Choose a clutch rated for your planned torque output, but keep in mind that more aggressive clutches can be challenging to drive smoothly.
2. Transmission:
   The WRX transmission is known to struggle under high torque. For street use, consider requesting a lower torque tune to extend the life of your drivetrain. For higher power builds, an STI 6-speed swap offers unparalleled durability but is a costly upgrade.
3. Shifter Mods:
   Short-throw shifters and upgraded bushings enhance shift feel and precision. However, these mods can accelerate wear on synchronizers and gears, so use them with caution.

Step 6: Aesthetic and Functional Add-Ons

1. Aerodynamics:
   Functional upgrades, like the APR hood scoop duct and intake snorkel, help reduce intake temperatures by directing airflow more efficiently. Front lips and rear wings from reputable brands like APR may also improve aerodynamics, though gains on a street car are often minimal.
2. Exhaust:
   While exhaust upgrades are primarily about sound, they can also provide modest performance gains. Choose one that aligns with your aesthetic and acoustic goals.

Key Takeaways

• Always start with a tune to unlock your WRX’s full potential.
• Prioritize modifications that align with your goals, focusing on quality and balance.
• Maintenance and professional tuning are crucial for reliability and performance.

Have fun crafting your perfect VB WRX, and remember: the build is as rewarding as the drive!