Introduction

For Subaru BRZ and Toyota GT86 owners seeking a more aggressive exhaust note and measurable performance gains, the Borla S-Type header stands out as a premium upgrade. This header is engineered to enhance exhaust flow, reduce backpressure, and deliver a signature deep growl that transforms the driving experience. In this comprehensive guide, we break down everything you need to know—from construction and dyno-proven power gains to installation tips and real-world sound characteristics. Whether you’re a weekend autocrosser or a daily driver wanting more character, the Borla S-Type BRZ header deserves a close look.

Understanding Borla S-Type Headers

Borla Performance has been a household name in exhaust innovation since 1978. Their S-Type lineup occupies the middle ground between a tame touring system and a full racing setup. The S-Type header for the FA20 engine in the Subaru BRZ and Scion FR-S is designed specifically to optimize the flow of exhaust gases while producing a distinctive, deep tone that many enthusiasts crave.

Construction and Materials

Every Borla S-Type header is crafted from T-304 stainless steel, a premium alloy known for its excellent corrosion resistance and longevity. Unlike cheaper 409 stainless steel, T-304 withstands high heat cycles without degrading, making it ideal for a header that lives directly off the engine. The tubing is mandrel-bent to ensure smooth transitions and consistent internal diameter, preserving flow velocity and preventing turbulence. The flanges are laser-cut and thick enough to resist warping under repeated thermal expansion.

Design Philosophy: Equal vs. Unequal Length

One key design decision in FA20 headers is the choice between equal-length and unequal-length primary tubes. The Borla S-Type header uses an equal-length design. This configuration ensures that exhaust pulses from each cylinder arrive at the collector evenly spaced, which maximizes scavenging efficiency especially in the mid-to-high RPM range. The result is a flatter torque curve and a more linear power delivery. The equal-length layout also produces a smoother, deeper exhaust note compared to the classic Subaru boxer rumble of unequal-length headers.

For many BRZ owners, this trade-off is worthwhile—replacing the offbeat thrum with a refined, aggressive growl.

Header Specs at a Glance

  • Material: T-304 stainless steel
  • Tube diameter: 1.625″ primary tubes into 2.5″ collector
  • Flanges: CNC-machined 3/8″ thick
  • Gaskets: Included high-temperature multi-layer steel
  • O2 sensor bungs: Two bungs (front O2 relocated as needed)
  • Coating: Available in polished or ceramic-coated (optional)
  • Warranty: Borla Million-Mile warranty

Performance Benefits: What the Dyno Shows

The primary reason to upgrade headers is performance. The FA20 engine in the BRZ is notoriously restricted from the factory due to emissions and noise regulations. A properly designed header like the Borla S-Type unlocks hidden horsepower and torque by allowing the engine to breathe freely.

Peak Power Gains

Independent dyno testing and real-world user reports indicate gains of 12–18 horsepower and 10–15 lb-ft of torque at the wheels on a stock BRZ. These gains are most pronounced between 4,000 and 7,000 rpm, which is exactly where the car pulls hardest during spirited driving. The torque bump in the midrange eliminates a portion of the notorious “torque dip” that plagues the FA20 around 3,500–4,500 rpm. While a header alone won’t completely erase that dip, pairing it with a quality tune (often recommended) can produce even more dramatic improvements—some shops report 20+ whp gains with a custom ECU calibration.

Exhaust Flow and Backpressure Reduction

The factory exhaust manifold on the BRZ is a log-style collector riddled with pinch points. In contrast, the Borla S-Type’s smooth mandrel bends and merge collector reduce backpressure by over 30% compared to stock. Lower backpressure means the engine spends less energy pushing exhaust out, which frees up rotating assembly work for the wheels. This efficiency translates to quicker throttle response and a more energetic feel from a standstill.

Spark Advance and Tuning Considerations

After installing the Borla S-Type header, the engine may run slightly lean due to the increased flow. This is because the stock ECU’s fuel maps are calibrated for the restrictive factory header. To fully realize the power potential—and to keep air-fuel ratios safe—many owners opt for an aftermarket tune via an Accessport or ECUTEK flash. A tune also raises the rev limiter, adjusts ignition timing, and can dial in aggressive camshaft profiles. If you choose to skip a tune, the header is still driveable, but you will leave some power on the table and risk running lean at high RPM under heavy load.

For most enthusiasts, a tune is a wise investment. Cobb Tuning offers reliable off-the-shelf maps that pair well with the Borla S-Type.

Sound Profile: The Deep Growl Examined

The Borla S-Type is famous for its acoustics. The equal-length tubes produce a more exotic, smooth tone compared to the flat, thumping sound of unequal-length headers. At idle, the BRZ with an S-Type header emits a low, rumbling burble—assertive but not obnoxious. Under part throttle, the note becomes a clean, muscular growl. At wide-open throttle, it transforms into a full-bodied snarl that sounds far more powerful than the 2.0L four-cylinder under the hood.

Compatibility with Cat-Back Exhausts

To get the best sound, consider pairing the Borla S-Type header with a compatible cat-back exhaust. The header alone (when mated to a stock cat-back) will increase volume by about 20–30% but won’t drastically change the character. Combine it with a Borla S-Type cat-back, and you get a fully harmonized system that’s aggressive yet refined—no annoying drone at highway speeds. Many owners also pair it with other popular cat-backs like the Injen SES or the HKS Legamax Premium. The key is to avoid overly loud mufflers that could make the setup unbearable on long trips.

Subispeed has customer sound clips that demonstrate this combination.

Drone and NVH Level

A concern with any header is cabin drone. The Borla S-Type strikes a careful balance. At cruising speeds (2,500–3,000 rpm) the drone is minimal—barely louder than stock inside the cabin. When you throttle down, the noise level rises but remains clean rather than boomy. The equal-length layout naturally avoids the harsh resonances that sometimes plague cheaper designs.

Owners who prioritize daily drivability often praise this header for being “aggressive when you want it, civil when you don’t.”

Installation Process: Step-by-Step and Pro Tips

Installing the Borla S-Type header is a moderate DIY job for those comfortable working under a car. Expect to spend about 3–5 hours for a first-timer, including jacking and safety preparation. Professional installation typically costs $200–$400 at an independent shop.

Tools and Supplies Checklist

  • Socket set (10mm, 12mm, 14mm, 17mm deep sockets)
  • Combination wrenches (12mm, 14mm)
  • Torque wrench (5–50 ft-lb range)
  • 3/8″ drive ratchet and extensions
  • Breaker bar for stubborn bolts
  • Jack and jack stands (at least two)
  • Wheel chocks
  • Penetrating oil (e.g., WD-40 or PB Blaster)
  • Safety goggles and mechanics gloves
  • High-temperature anti-seize compound
  • Replacement OEM exhaust gaskets (header-to-head and header-to-midpipe)

Detailed Installation Steps

  1. Prepare the vehicle: Park on a level surface, chock the rear wheels, and slightly loosen the lug nuts. Jack up the front of the car and place jack stands under the frame rails. Remove the front wheels for easier access (if desired).
  2. Remove the under-tray: Use a 10mm socket to remove the plastic under-engine cover. Set aside.
  3. Disconnect the battery: This prevents accidental airbag deployment or short circuits while working near the O2 sensors. Disconnect the negative terminal.
  4. Remove factory heat shields: The stock header has metal heat shields held by bolts or clips. Use penetrating oil on rusty bolts. Remove them and set aside; you may reuse them with the Borla header.
  5. Unbolt the stock header: The header connects to the cylinder head with 8 bolts (12mm head). Work from the top and bottom. A swivel socket and extension help reach the rear bolts. Next, unbolt the header from the front pipe (two 14mm bolts). Support the header as you remove the last bolt to avoid dropping it.
  6. Remove the O2 sensors: Use a 22mm O2 sensor socket to carefully unscrew both sensors from the stock header. Be gentle with the wires. Reapply anti-seize to the threads before installing into the new header.
  7. Prepare the mounting surfaces: Clean the exhaust port faces on the cylinder head with a plastic scraper and brake cleaner. Ensure no old gasket material remains. Install new OEM gaskets (usually included with the Borla kit).
  8. Install the Borla S-Type header: With a helper, position the header from below. Guide the O2 sensor bungs to the correct orientation. Start all eight header-to-head bolts by hand, then torque to the manufacturer’s specification (typically 35 ft-lb, but verify with Borla instructions). Work in a cross pattern to avoid warping the flange.
  9. Reconnect the front pipe: Use a new gasket between the header collector and the front pipe. Torque to 30 ft-lb.
  10. Reinstall heat shields: If reusing the stock shields, you may need to trim them slightly for clearance. Many aftermarket companies sell aftermarket heat shields designed for headers. This is optional but recommended to protect the intake and hood from radiant heat.
  11. Reconnect O2 sensors: Screw in the front O2 sensor into the bung closest to the cylinder head. The rear O2 sensor goes into the second bung, after the collector. Tighten to 30 ft-lb. Plug in the connectors.
  12. Reconnect the battery, lower the car, and check for leaks: Start the engine and let it idle. Listen for any exhaust leaks (hissing or ticking). Spray soapy water on each joint; bubbles indicate a leak. Tighten as needed.
  13. Test drive: After checking the fluid levels and ensuring everything is secure, take a short drive to heat-cycle the gaskets and listen for any unusual noises.

For a visual walkthrough, many BRZ owners have documented the process on the FT86 Club forum. This resource is invaluable for troubleshooting stubborn bolts or alignment issues.

Common Pitfalls and Solutions

  • Stuck bolts: The header-to-head bolts often seize due to heat cycles. Apply penetrating oil the night before and use a breaker bar gently. If a bolt snaps, a professional extraction may be needed.
  • O2 sensor wire length: The Borla header may reposition the sensors. If the wires are too short, you can buy harness extensions from Borla or a third party.
  • CE Light: If you delete the header catalytic converter (some S-Type versions are catless), the rear O2 sensor will trigger a check engine light unless the ECU is tuned. The catted version of the Borla S-Type includes a high-flow catalytic converter to avoid this.

Maintenance and Longevity

Borla’s T-304 stainless steel is extremely durable, but headers operate in harsh conditions. After the first few hundred miles, re-torque the header bolts (when cold) to ensure they haven’t loosened. Periodically inspect the welds for cracks, especially at the collector. If you live in a cold climate, road salt can cause cosmetic discoloration, but rust-through is rare. Applying a ceramic coating (either factory option or aftermarket) can reduce under-hood temperatures and maintain appearance.

Comparing Borla S-Type to Other BRZ Header Options

The BRZ/FR-S aftermarket is flooded with headers. Here’s how the Borla S-Type stacks up against popular alternatives:

vs. Tomei Unequal-Length Header

The Tomei header produces the iconic Subaru “rumble” due to its unequal-length runners. It trades some midrange torque for that classic sound. The Borla is smoother and delivers better top-end power. If you crave the flat-four burble, Tomei wins; for pure performance and a deep exotic note, Borla is superior.

vs. Perrin Equal-Length Header

Perrin’s equal-length header is similarly focused on flow and power. The Borla S-Type is generally more affordable and includes a million-mile warranty. Sound profiles are similar, but the Borla is slightly quieter at idle, making it more daily-driver-friendly.

vs. JDL Auto Design Header

JDL headers are hand-built and highly customizable, offered with options for thermal coatings, different collector types, and even unequal-length designs. They are often more expensive. Borla provides a more predictable, off-the-shelf solution with broad tuning support.

Is a Tune Necessary?

While you can run the Borla header without a tune, the benefits are significantly limited. The factory ECU’s closed-loop fuel trims can compensate partially, but at wide-open throttle the engine runs leaner than optimal, reducing power and increasing exhaust gas temperatures. For safety and performance, a high-quality tune is strongly advised. Many tuners offer remote flashes for ECUTEK or Cobb Accessport that specifically match the Borla S-Type header. The cost of a tune ($400–$600) is a small price for an extra 10–15 whp and peace of mind.

Conclusion: Who Should Buy Borla S-Type Headers?

The Borla S-Type header is an excellent upgrade for any BRZ owner who wants a deeper, more refined sound and real, dyno-verified power gains. Its equal-length design delivers a smooth torque curve, higher peak power, and a growl that turns heads without causing cabin fatigue. Installation is achievable for intermediate DIYers, but professional help ensures a leak-free fit. With Borla’s million-mile warranty and robust T-304 steel construction, this header is a long-term investment in your driving pleasure.

For those who value aural excitement, improved throttle response, and a platform that responds well to further modifications, the Borla S-Type header should be at the top of your list. Combine it with a quality tune and a cat-back exhaust, and you’ll transform your BRZ into a genuinely engaging machine. Whether you’re carving canyons or commuting, the Borla S-Type makes every drive sound and feel more rewarding.