The FA20 engine, a 2.0-liter flat-four produced by Subaru, has become a cornerstone of modern sports car performance. Found in the Subaru BRZ, Scion FR-S, and Toyota GT86, as well as later Subaru WRX models, the FA20 strikes a rare balance between naturally aspirated responsiveness and forced-induction potential. For enthusiasts looking to unlock its full capabilities, the aftermarket parts scene is deep—but choosing the right brand can make or break a build.

In this comprehensive guide, we compare three of the most respected names in FA20 performance: Perrin Performance, Grimmspeed, and Invidia. From intakes and exhausts to turbo blankets and boost controllers, we break down their strengths, weaknesses, and the real-world gains they deliver. Whether you're chasing peak horsepower on a dyno or a more responsive daily driver, this comparison will help you make an informed decision.

Overview of the FA20 Engine

The FA20 is a 2.0-liter horizontally opposed (flat) four-cylinder engine. Subaru developed it as a lighter, more fuel-efficient successor to the EJ series, while also targeting higher revs and better thermal efficiency. The naturally aspirated FA20D variant produces around 200-205 horsepower and 151 lb-ft of torque in the BRZ/86, while the turbocharged FA20F found in the WRX and Levorg pushes 268 horsepower and 258 lb-ft from the factory.

Key design features include:

  • Aluminum block and heads – saves weight compared to cast iron EJ engines
  • Dual overhead camshafts with AVCS (variable valve timing) on intake and exhaust
  • Direct injection (D-4S) on some variants, combining port and direct injection for cleaner combustion
  • Low center of gravity – inherent to flat engines, improving handling dynamics

Tuning potential is excellent: naturally aspirated builds can see 230-240 wheel horsepower with cams, headers, and a tune, while turbocharged FA20Fs can easily exceed 350 wheel horsepower with bolt-on parts and an upgraded intercooler. However, the engine's direct injection system can lead to carbon buildup on intake valves, making catch cans and periodic cleaning a wise precaution for long-term reliability.

Brand Comparisons

Perrin Performance

Founded in 2003 by Jeff Perrin, this Oregon-based company has been a mainstay in the Subaru aftermarket for two decades. Perrin is known for extensive research and development, often releasing products only after rigorous track and street testing. Their FA20 lineup covers nearly every bolt-on category, from intakes and turbo inlets to intercoolers and exhaust systems.

  • Product Range: Cold air intakes, short ram intakes, cat-back exhausts, catted and catless downpipes, front-mount intercooler kits, blow-off valves, and drivetrain components like shift knobs and bushings.
  • Quality: TIG-welded stainless steel and aluminum construction. Many parts are powder-coated or ceramic-coated for heat management. Fitment is consistently praised; almost no "massaging" required during installation.
  • Performance Gains: Users on forums like FT86Club and NASIOC report 8-12 whp gains from a Perrin intake + tune alone. Their cat-back exhaust systems add 5-8 whp and shed significant weight over stock. For forced-induction builds, the Perrin front-mount intercooler reduces intake temperatures by 30-40°F on the dyno.

Pros and Cons of Perrin

  • Pros: Excellent build quality, thorough instructions, good customer support, proven dyno results.
  • Cons: Premium pricing; often $50-100 more than competing brands for similar parts. Some intake designs can cause minor heat soak in stop-and-go traffic (mitigated with a heat shield).

Grimmspeed

Grimmspeed started as a small fab shop in Tennessee in 2004, specializing in turbocharged Subaru performance. They gained a reputation for solving common problems—like restrictive factory boost control systems—with elegantly simple aftermarket parts. Their FA20 catalog includes several unique items not found from other brands.

  • Product Range: Turbo blankets, electronic boost controllers, exhaust manifolds (unequal length for the BRZ/86), intake manifolds, throttle body spacers, and lightweight crank pulleys.
  • Quality: Grimmspeed parts are machined from billet aluminum or formed from stainless steel, then ceramic-coated in-house. The boost controllers are known for precise boost targeting without the complexity of standalone ECU modules.
  • Performance Gains: Their turbo blanket reduces under-hood temperatures by 20-35°F, allowing more consistent power on track days. The unequal-length exhaust manifold for the FA20D (BRZ/86) replicates the classic Subaru rumble while gaining 4-6 whp. On turbo FA20 builds, the Grimmspeed boost controller enables quicker spool and higher peak boost without overboosting.

Pros and Cons of Grimmspeed

  • Pros: Innovative problem-solving products, excellent heat management coatings, strong community following, competitive pricing.
  • Cons: Smaller overall product range than Perrin or Invidia; some items are niche (e.g., throttle body spacer). Install instructions could be more detailed for first-time DIYers.

Invidia

Invidia is a California-based company founded in 1995, initially focusing on Japanese domestic market exhaust systems. They have since expanded to cover Subaru, Mitsubishi, Nissan, and Honda platforms. Invidia’s FA20 lineup is heavily weighted toward exhaust systems—they are arguably the most popular choice for aftermarket cat-back and downpipe setups on the BRZ/86 and WRX.

  • Product Range: Cat-back exhausts (single exit, dual exit, quad tip), downpipes (catted and catless), headers for the FA20D, and limited intake systems. They recently introduced a titanium exhaust option for weight reduction.
  • Quality: 304 stainless steel with mandrel bends, robotic TIG welding, and CNC-machined flanges. Fitment is consistently good, though some early WRX downpipe models required slight adjustment. The polished or burnt-titanium tips are a visual highlight.
  • Performance Gains: A typical Invidia cat-back on a stock FA20D gains 5-7 whp and 4-5 lb-ft of torque. Pairing their catless downpipe with a tune on a turbo FA20F yields 20-25 whp gains. The aggressive exhaust note is a major selling point—deeper than Perrin's offerings, with minimal drone at highway speeds.

Pros and Cons of Invidia

  • Pros: Outstanding sound character, affordable pricing (often $200-300 less than Perrin for similar cat-backs), widespread availability, well-tested fitment on BRZ/86/WRX.
  • Cons: Limited product range beyond exhausts; some parts (like headers) may not be as refined as Grimmspeed's. Customer service response times can be slower than Perrin's.

Performance Parts Comparison

To help you decide, here's a head-to-head comparison across the three brands in key categories that matter to FA20 builders.

Category Perrin Grimmspeed Invidia
Intake Power Gains (N/A) 8-12 whp with tune Limited intakes; focus on other components Minimal gains; not a primary focus
Exhaust Power Gains (N/A) 5-8 whp (cat-back) 4-6 whp (manifold), 5-8 whp (cat-back) 5-7 whp (cat-back)
Exhaust Sound Character Deep, refined, moderate volume Classic Subaru rumble (UEL), moderate volume Aggressive, low, slightly louder
Build Quality Excellent – premium materials, precise fit Excellent – billet/ceramic coatings, innovative Very good – stainless steel, robotic welding
Price (Cat-back example) $800-1,200 $700-1,100 (limited options) $550-850
Best For Complete builds, reliability, proven results Boost control, heat management, part upgrades Bolt-on exhaust upgrades, aggressive sound

Note: All gains listed are approximate and depend on supporting modifications (tune, fuel, ambient temperature).

Choosing the Right Brand for Your Build

Your choice between Perrin, Grimmspeed, and Invidia should align with your build philosophy and budget.

For the Daily Driver Looking for Reliable Gains

Perrin is the safe bet. Their parts are thoroughly tested, fit perfectly, and come with excellent customer support. If you're planning a comprehensive build (intake, downpipe, intercooler, and exhaust), Perrin's ecosystem ensures all components work together without guesswork. The three-year warranty on many parts also provides peace of mind.

For the Track Enthusiast Focused on Consistency

Grimmspeed excels at managing the thermal and boost dynamics that matter on a road course. An FA20 with a Grimmspeed turbo blanket, boost controller, and aftercooler intake will maintain power through a 20-minute session better than one with just a tune and downpipe. Their exhaust manifold for the FA20D also adds that iconic Subaru sound without sacrificing top-end flow.

For the Builder on a Budget Who Wants Great Sound

Invidia delivers the best bang for the buck in the exhaust category. Their prices are significantly lower than Perrin's, and the quality is still high. If your primary goal is a more aggressive exhaust note and modest power gains, Invidia is the logical choice. Combine an Invidia cat-back with a Perrin intake and a tune for a well-balanced, cost-effective setup.

Installation Considerations

All three brands provide parts that are designed for DIY installation, but there are nuances to be aware of:

  • Intakes: Perrin's cold air intake requires removal of the front bumper and wheel liner for the filter housing. Grimmspeed does not offer a dedicated FA20 intake; for that you'd look at Perrin or other brands. Invidia's intake options are limited to a short ram design that is easier to install but more prone to heat soak.
  • Downpipes: Invidia downpipes are straightforward on the WRX, but the catted version may require an oxygen sensor extension harness. Perrin offers both catted and catless options with integrated fittings. Grimmspeed does not produce downpipes for the FA20 platform at this time.
  • Exhaust Manifolds: Grimmspeed's unequal-length header for the BRZ/86 requires removing the stock manifold and heat shield—a 3-hour job for experienced DIYers. Perrin offers a similar product but focuses more on mid-pipes and exhausts.

Always follow the manufacturer's torque specifications and use new gaskets when installing exhaust components. A professional tune is mandatory after any intake, downpipe, or header change to avoid lean conditions and maximize gains.

Combining Brands for Optimal Results

There's no rule that says you must stick to a single brand. In fact, many high-horsepower FA20 builds mix components from all three manufacturers. For example:

  • Perrin intake + Grimmspeed turbo blanket + Invidia cat-back – yields responsive throttle, lower IATs, and a great sound without breaking the bank.
  • Grimmspeed boost controller + Perrin front-mount intercooler + Invidia downpipe – an excellent foundation for a 350+ whp turbo build.
  • Grimmspeed unequal-length headers + Invidia cat-back – for naturally aspirated BRZ/86 owners who want the classic Subaru rumble with 7-10 total whp gains.

When mixing brands, pay attention to pipe diameters and flange compatibility. Most 3-inch exhaust components are interchangeable, but some downpipes may have different lengths. Check forum threads or call the manufacturer if unsure.

Performance Part Combinations: Intake, Exhaust, and Tune

The fastest way to unlock FA20 power is a three-step sequence: a high-flow intake, a less-restrictive exhaust (cat-back or turbo-back), and a professional ECU tune. Here's how each brand fits into that formula:

  • Intake: Perrin's cold air intake is the gold standard for the FA20D and FA20F. It reduces restriction while maintaining filter protection. Expect 8-12 whp with a tune. Grimmspeed does not make intakes; Invidia's short ram is a secondary option but tends to pull hot air from the engine bay.
  • Exhaust: Invidia's cat-back offers the best value and most aggressive sound. Perrin's cat-back is quieter but flows slightly better on some dynos. Grimmspeed's cat-back is their least popular product—most GRIM owners buy their headers and boost control parts instead.
  • Tune: All three brands recommend using a reputable tuner (e.g., Delicious Tuning, Cobb, ECUTek) to calibrate for the new parts. A generic off-the-shelf map will leave power on the table and may cause knock.

With these three modifications, naturally aspirated FA20s typically gain 20-25 whp, while turbo FA20s see 35-50 whp improvements depending on boost levels.

Conclusion

Perrin, Grimmspeed, and Invidia each bring distinct strengths to the FA20 performance parts market. Perrin is the comprehensive, research-backed choice for builders seeking proven reliability and a full product suite. Grimmspeed is the innovator, solving niche problems like heat management and boost control with beautifully engineered parts. Invidia is the exhaust specialist delivering aggressive sound and solid performance at a lower price point.

Your final decision should reflect your performance goals, budget, and how much time you're willing to spend on installation and tuning. Regardless of which brand you choose, the FA20 engine has tremendous headroom—and these three companies provide the components to help you reach it. To see the full product lines, visit their official sites: Perrin Performance, Grimmspeed, and Invidia USA.

Happy building—and may your FA20 sing at redline.