BC0111 – Mitsubishi 4G63 Evo VIII Stage 2 Camshafts – Street/Strip Spec

For the dedicated Mitsubishi 4G63 tuner seeking to unlock the definitive street-performance character of their Evolution VIII, the Brian Crower BC0111 Stage 2 Camshafts represent a calculated engineering solution. These are not mere drop-in components; they are a core part of a strategic air-flow overhaul designed for the enthusiast who demands tangible, seat-of-the-pants gains without sacrificing daily driveability or broad powerband efficacy. Engineered specifically for the turbocharged 4G63 (Evo VIII) platform, the BC0111 profile is the result of extensive dyno and track testing, offering a refined yet aggressive lift and duration curve that works in concert with supporting modifications to push the engine well beyond its factory potential. This is the camshaft specification for those building a responsive, tractable, and brutally effective street machine with occasional strip capability, bridging the gap between aggressive street performance and all-out race setups.

Precision Engineered Profile for Forced Induction

The art of camshaft design for a turbocharged application like the 4G63 differs fundamentally from that of a naturally aspirated engine. The BC0111 Stage 2 cams master this distinction. Their profile is optimized to enhance volumetric efficiency within the engine’s primary operating range, typically between 3,000 RPM and 7,200 RPM. The increased duration and lift work synergistically with the turbocharger by improving exhaust scavenging. This reduced backpressure in the exhaust manifold allows the turbo to spool more efficiently, translating to reduced lag and a sharper throttle response. Furthermore, the enhanced intake lift and duration permit a greater mass of air to enter the cylinder during the critical intake valve overlap period, which is meticulously tuned to avoid reversion issues common in less refined profiles. This precise calibration ensures the engine breathes with greater authority, filling the cylinders more completely for a denser charge, which directly correlates to increased power and torque across a remarkably usable powerband.

Technical Specifications & Design Philosophy

Brian Crower’s BC0111 camshafts are machined from premium-grade steel billets, utilizing CNC precision to ensure lobe-to-lobe accuracy and perfect journal concentricity—critical for maintaining stable valvetrain dynamics at high RPM. The lobes are then treated with a specialized surface hardening process to combat wear and micro-weld, ensuring longevity even under high spring pressures. The specification itself is a hallmark of the “Stage 2” or “Street/Strip” category, offering a significant bump over stock or mild “Stage 1” cams without venturing into the territory of requiring radical headwork or standalone engine management for basic operation.

The 272° advertised duration with a 112° Lobe Separation Angle is a classic and proven street performance formula for the 4G63. This LSA provides a moderate amount of overlap, which improves high-RPM power and scavenging while remaining narrow enough to preserve strong low-end and mid-range torque. The differential lift between intake and exhaust (10.85mm vs. 10.30mm) is intentional, prioritizing intake flow to match the demands of a turbocharged system while the exhaust profile efficiently evacuates spent gases. For a deeper dive into how duration and LSA affect turbocharged performance, consider reading this technical explanation on lobe separation angle from a reputable industry source.

Performance Benefits & Required Supporting Mods

Installing the BC0111 camshafts is a pivotal upgrade that transforms the engine’s personality. The benefits are systematic and significant when paired with the correct supporting modifications.

• Expanded Powerband: Shifts the power curve higher while retaining strong mid-range pull, typically adding 25-50+ wheel horsepower depending on turbo and tune.
• Enhanced Turbo Spool & Response: Improved exhaust scavenging reduces turbine backpressure, allowing the turbo to spin up quicker, mitigating lag.
• Increased Volumetric Efficiency: The engine becomes a more effective air pump, moving a greater mass of air per cycle for more complete combustion.
• Aggressive Idle Quality: The increased overlap produces a distinctive, choppy idle that signifies the performance within.
• Platform for Larger Turbos: Effectively supports the airflow needs of larger turbochargers (e.g., FP Red, 20G, GT3076R) that would be choked by stock camshafts.

To realize these benefits safely and fully, these cams are not a standalone modification. Mandatory supporting mods include upgraded valve springs and retainers (such as Brian Crower’s BC0109 kit) to control the increased lift and prevent valve float. A high-flow fuel pump, larger injectors (650cc minimum, 1000cc+ recommended for future growth), and an aftermarket engine management system or a professional ECU flash are essential to properly meter fuel and optimize ignition timing for the new airflow characteristics. A turbo-back exhaust and front-mount intercooler are also considered prerequisite supporting mods for a Stage 2 build.

Vehicle Fitment & Installation Notes

The BC0111 camshafts are engineered as a direct replacement for specific 4G63 platforms. Correct fitment is critical for valvetrain geometry and performance.

Primary Fitment:

• 2003-2005 Mitsubishi Lancer Evolution VIII (4G63 Turbo, DOHC)

Compatibility & Notes:

• Will physically fit the 2006-2007 Evolution IX cylinder head, but tuning requirements differ (MIVEC). Non-MIVEC tuning solutions are required for the IX.
• Also compatible with 1995-1999 Eagle Talon / Mitsubishi Eclipse GST/GSX (7-bolt 4G63) applications, but always verify part number compatibility for specific years.
• Not compatible with Evolution X (4B11T) or any MIVEC-equipped engine without disabling/deleting the MIVEC system.

Installation requires standard camshaft replacement procedures: locking the engine at Top Dead Center (TDC), carefully marking and removing the timing belt, and using proper tools to secure the cam gears during removal/installation. A professional valve timing adjustment and verification with a degree wheel is strongly recommended to ensure the cams are installed to the specified centerline for optimal performance. Post-installation, a fresh oil and filter change is advised to remove any potential assembly debris.

The Verdict: The Strategic Street Performance Choice

The Brian Crower BC0111 Stage 2 Camshafts are a cornerstone modification for the serious Evo VIII enthusiast building a balanced, high-output street machine. They avoid the extremes of race-only profiles that decimate low-end drivability, instead offering a refined, performance-optimized curve that works harmoniously with the 4G63’s turbocharged architecture. When integrated into a complete Stage 2 build with proper fuel, tuning, and turbo support, these cams facilitate a transformative leap in power, throttle response, and overall engine character. They deliver the aggressive sound and tangible performance that define a purpose-built street performer, making them an intelligent and high-return investment for unlocking the next level of 4G63 evolution.