Unlocking FA20 Potential: Optimizing Camshafts and Pulleys for 245 Horsepower

The Subaru BRZ, Scion FR-S, and Toyota 86 have earned their place as driver’s cars thanks to a low center of gravity, precise steering, and a chassis that rewards skill. But the FA20 engine—a 2.0-liter naturally aspirated boxer—leaves many owners wanting more. With a factory output of roughly 200 horsepower at the crank and around 170 at the wheels, hitting a genuine 245 wheel horsepower (or roughly 285-290 crank) requires a well-planned combination of bolt-ons, fuel system work, and internal modifications. Among the most effective upgrades for reaching this power goal are performance camshafts and lightweight or underdrive pulleys.

This guide covers the theory behind these upgrades, the best components currently available, installation pitfalls to avoid, and the supporting modifications needed to make 245 wheel horsepower a reality. We’ll also explain how these parts work together—and why a proper tune is non-negotiable.

FA20 Engine Design and Airflow Limitations

The FA20 uses a unique combination of direct injection (DI) and port injection. This dual-injection system helps manage carbon buildup and allows high compression (12.5:1 on earlier versions, 12.0:1 on later revisions). While efficient, the factory cylinder head ports and cam profiles are optimized for emissions and fuel economy rather than peak high-rpm horsepower.

The stock camshafts offer modest lift and duration, with relatively early intake valve closing that builds cylinder pressure for low-end torque but strangles flow above 6,500 RPM. Similarly, the crank pulley is a heavy harmonic damper designed primarily for noise, vibration, and harshness (NVH) control, not for reduced rotational mass. Replacing these two items addresses the engine’s biggest airflow and parasitic loss bottlenecks.

How Camshafts Increase Power

Camshafts control when and how long the intake and exhaust valves are open. Increasing lift allows more air/fuel mixture into the cylinder, while longer duration keeps the valves open longer at high RPM, improving volumetric efficiency. However, too much duration can cause reversion at low RPM, hurting drivability. The key is choosing a profile that builds power from 4,000 RPM upward while retaining enough signal for the mass airflow sensor and proper idle quality.

For a 245 wheel horsepower target on the FA20, a “Stage 2” or “mid-range” cam profile is ideal—typically with around 270-275 degrees of advertised duration and lift near 11.5-12.0 mm. These cams shift the power band without killing low-end torque, especially when paired with appropriate supporting modifications.

Best Camshaft Upgrades for the FA20

The aftermarket offers several well-engineered camshaft sets that have proven results on dynos. Below are three options that consistently help owners reach or exceed the 245 whp mark.

GSC Power-Division S2 Camshafts

GSC Power-Division S2 camshafts are a staple for FA20 builds aiming over 240 whp. With 11.5 mm lift and 274 degrees of duration on the intake and 280 degrees on the exhaust, they offer a noticeable mid-range punch and extend the power band to about 7,500 RPM. These cams maintain decent idle quality with a slightly aggressive lope and work well with upgraded valve springs (highly recommended). Owners pairing these with full exhaust (catless headers, overpipe, front pipe) and a good intake often see 25–35 whp gains, putting a well-tuned car comfortably over 245 whp.

BC Racing Stage 2 Camshafts

BC Racing Stage 2 camshafts are a popular alternative, featuring 11.3 mm lift and 272 degrees duration. They prioritize mid-range torque over top-end peak, making them a strong choice for street-driven cars that see autocross or track days. On the dyno, they typically add 20–28 whp with a more aggressive tune, and the torque curve remains flat from 5,000 to 7,200 RPM. Some tuners note that BC S2 cams respond well to adjustable cam gears for fine-tuning overlap.

Torque Solution Camshafts

Torque Solution camshafts are designed for a balance between performance and daily drivability. Their Stage 2 profile uses 11.2 mm lift and 270 degrees duration, which retains smooth idle and good part-throttle response. While they don’t produce the highest peak numbers, they are easier to tune and less likely to cause trouble with the stock ECU’s fuel tables. Gains are modest at 15–20 whp, but reliability is excellent.

Pulley Upgrades: Reducing Rotational Mass and Parasitic Drag

The FA20’s factory crank pulley weighs nearly 2.5 kg (about 5.5 lbs) and includes an elastomer ring to dampen vibrations. This design adds rotational inertia that the engine must overcome during acceleration. Replacing it with a lightweight pulley (typically around 0.6–0.9 kg) frees up horsepower by reducing the energy needed to spin the crankshaft and the accessories (alternator, water pump, power steering pump).

Similarly, underdrive pulleys for the alternator and power steering pump slow those accessories slightly, further reducing parasitic loss. However, underdrive pulleys can cause charging or cooling issues at idle if not matched correctly, so lightweight crank pulleys are generally safer for street cars.

Grimmspeed’s lightweight crank pulley is CNC-machined from 6061 aluminum and weighs 0.8 lb—over 80% lighter than stock. Its design eliminates the rubber harmonic damper, which is acceptable because the FA20’s bottom end is well-balanced, and the RPM range most relevant for performance (2,500–8,000 RPM) doesn’t produce dangerous harmonics with a lightweight pulley. Gains are typically 5–8 whp, though the more significant benefit is quicker throttle response and a faster-revving engine, especially when matched with a light flywheel.

Torque Solution Underdrive Pulley Set

Torque Solution’s underdrive pulley set includes a lightweight crank pulley and reduced-diameter accessory pulleys. Fit and finish are excellent, and the set is designed to work with the stock belt tensioner without slipping. On a cammed FA20, underdrive pulleys can add another 3–5 whp over a lightweight crank pulley alone, but you must verify belt alignment and accessory function after installation.

Combined Gains: Camshafts + Pulleys + Supporting Mods

A standalone camshaft or pulley upgrade will not deliver 245 wheel horsepower on the FA20. The cam and pulley must be part of a cohesive package that includes:

  • Full exhaust: Catless headers (e.g., JDL or Ace), overpipe, front pipe, and a high-flow cat or catback. Headers alone are worth 15–20 whp.
  • Cold air intake: A well-designed intake like the Perrin or Grimmspeed can add 5–8 whp and improve throttle response.
  • Fuel system support: At 245 whp, the stock fuel pump and injectors are near their limit. A higher-flow fuel pump (e.g., DW200) and possibly a flex fuel sensor for E85 are recommended.
  • ECU tune: Custom tuning via EcuTek or OpenFlash Tablet is mandatory. A base map from the cam manufacturer is a starting point, but a dyno tune ensures the air/fuel ratio is safe and ignition timing is optimized.
  • Valve springs and retainers: Stronger springs prevent valve float at high RPM with aggressive cams. GSC or Supertech double valve springs are common choices.

Dyno results from multiple tuners show that a car with headers, intake, exhaust, Stage 2 cams, and a lightweight crank pulley typically makes between 240 and 260 whp on 93 octane, and 260–275 whp on E85. The pulley contributes roughly 5–10 whp of that gain, while the cams add 15–30 whp depending on the header design and tune aggressiveness.

Installation: What to Expect

Camshaft installation requires removing the valve covers, timing chain, and timing gears. It is not a beginner job. Key steps include:

  • Setting the engine to top dead center on cylinder #1.
  • Marking or locking the timing chain alignment.
  • Removing the camshaft caps and swapping the camshafts.
  • Reinstalling with new cam cap bolts (torque-to-yield) and new seals.
  • Checking valve-to-piston clearance—on Stage 2 cams, it’s usually safe, but aftermarket pistons may require different timing.

Pulley installation is simpler: remove the serpentine belt, use a crank pulley holder tool, and torque the crank bolt to 145 ft-lbs (plus 180 degrees on some models). Always replace the crank bolt with a new one.

Tuning After Camshaft and Pulley Installation

The phrase “a tune is not optional” cannot be overstated. Camshafts completely change the engine’s volumetric efficiency and the airflow signal read by the mass airflow sensor. Without recalibrating fuel and ignition tables, the engine will run lean at high load, risking detonation. A professional tuner will adjust the MAF scaling, fuel trims, and cam timing angle tables (if using adjustable gears) to hit the target air/fuel ratio of around 12.5:1 for gasoline or 7.5:1 for E85.

Most tuners recommend starting with the cam manufacturer’s suggested cam timing (e.g., 0 degrees for both intake and exhaust relative to TDC) and then advancing or retarding in 1-degree increments on the dyno to find the peak. A typical result for Stage 2 cams on the FA20 is 3–4 degrees of advance on the intake and 2 degrees of retard on the exhaust for maximum mid-range torque.

Cost Considerations and Value Per Horsepower

Here’s a rough estimate of parts and labor (US pricing as of early 2025):

  • Stage 2 camshafts: $700–$1,100
  • Valve springs and retainers: $250–$400
  • Lightweight crank pulley: $120–$200
  • Headers: $600–$1,200
  • Intake: $300–$500
  • Fuel pump: $150–$250
  • EcuTek tune + license: $800–$1,200
  • Labor for cam install (8–12 hours): $800–$1,500

Total cost: roughly $3,500–$5,000. For that, you gain 40–60 whp over stock, which puts the cost at roughly $60–$100 per wheel horsepower. That’s competitive for a naturally aspirated engine. If you do the work yourself, the savings are substantial.

Conclusion: A Proven Path to 245 Wheel Horsepower

Reaching 245 wheel horsepower in a BRZ or 86 requires a systematic approach. Camshafts and pulleys are two of the highest-value modifications when combined with proper headwork, fuel system, and tuning. The GSC S2 cams and Grimmspeed lightweight crank pulley represent a proven combination that, when paired with exhaust and a good tune, will reliably exceed the 245 whp target while maintaining daily drivability.

For owners who want a more aggressive top-end rush, the BC Racing Stage 2 cams are a strong choice. Those prioritizing smoothness and idle quality should consider Torque Solution. Regardless of the specific parts chosen, investing in professional installation and a custom dyno tune ensures the engine’s longevity and maximizes the power potential of these upgrades.

The FA20 may not be a high-strung racing engine from the factory, but with the right camshafts and pulleys, it can become a responsive, powerful, and thoroughly enjoyable powerplant that transforms the Subaru/Toyota “twins” into serious track-day weapons or thrilling street machines.