Installation of Brembo Big Brake Kit on Evo 9: Performance and Cost Analysis ($2,500)

The Mitsubishi Lancer Evolution 9 remains a benchmark in the world of all-wheel-drive performance sedans. Its turbocharged 4G63 engine and advanced drivetrain deliver a driving experience that is both visceral and capable. However, as owners push the chassis toward higher power levels—500, 600, or even 700 wheel horsepower—the factory braking system becomes a critical weak point. While the stock Brembo calipers were competitive in their era, modern driving demands and increased performance require a substantial upgrade.

Installing a full Brembo Big Brake Kit (BBK) addresses this need directly. At a total investment landing around $2,500, this modification is frequently cited as one of the most effective safety and performance upgrades available for the Evo 9. This analysis covers the components involved, the measurable performance gains, a detailed installation walkthrough, and a comprehensive cost breakdown to help owners make an informed decision.

Stock Braking System and Its Limitations

Mitsubishi equipped the Evo 9 with bronze-colored Brembo calipers as standard equipment. These were 4-piston front calipers clamping down on 320mm x 30mm single-piece rotors. While a respectable setup for a 2006-era sports sedan, the stock system has well-documented shortcomings when subjected to aggressive use.

The primary weakness is thermal management. The single-piece iron rotors expand and contract uniformly, which leads to a phenomenon known as "taper wear" on the pads. More critically, the mass of the stock rotors is insufficient for heavy track use, causing the brake fluid to boil and resulting in immediate, dangerous brake fade. The stock brake lines, made of rubber, also expand under high pressure, creating a spongy pedal feel that reduces driver confidence and modulation accuracy.

For a daily driver, the stock brakes are adequate. For any enthusiast planning to attend track days, autocross events, or even aggressive mountain road driving, upgrading to a proper big brake kit is not a luxury; it is a prerequisite for safe operation.

The Brembo Big Brake Kit: Components and Specifications

Brembo offers several big brake kit configurations for the Evo 8 and 9 chassis. The most common setup is the Gran Turismo (GT) kit, which has evolved over the years. The kit is designed as a direct bolt-on replacement, requiring minimal modification to the vehicle.

Standard Kit Contents

• Larger Two-Piece Rotors: Most BBKs for the Evo 9 utilize 355mm x 32mm rotors. The two-piece design uses an aluminum hat bolted to a cast-iron braking ring. This allows the iron ring to expand and contract independently of the hat, drastically reducing the risk of warping and improving heat dissipation.
• Monobloc Calipers: The upgrade typically features 6-piston calipers in the front. Monobloc construction means the caliper body is machined from a single piece of aluminum, making it significantly stiffer and lighter than the stock 4-piston units.
• High-Performance Brake Pads: Kits often come pre-loaded with high-friction pads, such as the Ferodo DS2500 or equivalent compounds, engineered for a high coefficient of friction across a wide temperature range.
• Stainless Steel Brake Lines: The rubber factory lines are replaced with braided stainless steel lines (PTFE-lined) to eliminate expansion under pressure. This provides a firm, consistent pedal feel.
• Mounting Brackets and Hardware: Precision-machined brackets allow the new calipers to sit perfectly over the larger rotors. All necessary bolts, shims, and clips are included.

Wheel Fitment Considerations

A critical factor before purchasing is wheel clearance. The stock Evo 9 Enkei wheels will not clear a 355mm BBK without spacers. Most owners pair this upgrade with aftermarket 17x9 or 18x9.5 wheels. A minimum wheel diameter of 17 inches is required, but wheel spoke design and offset are equally important. A test fit or verification against known fitment databases (such as those on EvolutionM forums) is strongly recommended before purchasing the kit.

Performance Analysis: Quantifying the Upgrade

Upgrading to a Brembo BBK offers measurable improvements in several key areas of vehicle dynamics.

Stopping Power and Modulation

The increase in rotor diameter from 320mm to 355mm provides a 35mm increase in the friction radius. This mechanical leverage allows the calipers to generate significantly more stopping torque with the same pedal pressure. The 6-piston caliper also distributes pad pressure more evenly across the pad surface compared to the stock 4-piston design. The result is a shorter 60-0 mph stopping distance, often reduced by 10-15 feet in controlled tests, and a pedal that offers precise modulation, making it easier to trail-brake into corners.

Heat Dissipation and Fade Resistance

Heat is the enemy of braking performance. The larger mass of the 355mm rotor provides a greater thermal capacity, meaning it takes longer for the system to reach critical temperatures. The two-piece rotor design is the key performance feature here. The aluminum hat acts as a heat sink, drawing heat away from the iron ring and the hub assembly. The open design of the GT calipers also allows for high-volume airflow through the caliper body. This combination allows the driver to perform multiple high-speed braking events from 130+ mph without experiencing the brake fade associated with boiling fluid.

Weight and Unsprung Mass

While the iron braking ring is larger, the use of an aluminum hat and the monobloc caliper results in a net weight reduction compared to the stock single-piece rotor and caliper assembly. This reduction in unsprung weight improves suspension compliance and steering response. Less mass at the corners allows the dampers to keep the tires in better contact with the road surface over bumps and undulations.

Installation Walkthrough: A Comprehensive Guide

Installing a BBK is a straightforward job for an intermediate mechanic, but it requires attention to detail and proper safety procedures. This guide assumes the vehicle is equipped with a compatible set of wheels.

Tools and Safety Equipment

• Hydraulic floor jack and four sturdy jack stands
• Torque wrench capable of reading up to 100 lb-ft
• Flare nut wrench set (for brake lines)
• Socket set with extensions
• Brake piston spreader or large C-clamp
• High-temperature brake grease (Nickel-based preferred)
• New DOT 4 or DOT 5.1 brake fluid (1 liter)
• Teflon tape or new copper washers for banjo fittings
• Catch bottle for old brake fluid

Removal of Factory Components

Start by safely lifting the vehicle and securing it on jack stands. Remove the wheels. The stock calipers are removed by unbolting the two 17mm guide pins. The caliper can then be suspended with zip ties to avoid stressing the brake line. Remove the rotors; on an Evo 9, these often require a 12mm hex key (Allen) to remove the retaining screw, though they may be seized. Use penetrating fluid if necessary. The stock dust shield (splash guard) will likely need to be trimmed or removed entirely to accommodate the larger rotors. This can be done with a set of high-quality tin snips.

Bracket and Rotor Installation

Clean the hub face thoroughly with a wire brush to remove any rust or debris, as this prevents rotor runout. The new Brembo aluminum hats slide over the wheel studs. Torque the rotor retention bolts to the manufacturer's specification (usually around 15-18 lb-ft). Next, mount the adapter brackets to the steering knuckle using the provided high-strength bolts. Apply a thread-locker (Loctite 242) to these bolts and torque them to 80 lb-ft. This is a critical step; a loose bracket can cause catastrophic failure.

Caliper and Pad Installation

Before installing the caliper, retract the pistons using a spreader tool. Apply a thin layer of high-temperature brake grease to the back of the new pads. Install the pads into the caliper. Place the caliper over the rotor and onto the adapter bracket. Use the provided hardware to secure the caliper. Torque the caliper-to-bracket bolts to roughly 75-80 lb-ft. This precise torque is essential for maintaining clamp force without distorting the caliper mounting ears.

Brake Line Connection and Bleeding

Remove the stock rubber brake line. The new stainless steel line will route from the hard line on the chassis to the caliper. Use new copper or aluminum crush washers on the banjo fitting at the caliper. Torque the banjo bolt to 25-30 lb-ft. Check for clearance at full steering lock to ensure the line does not stretch or contact the tire. Bleeding the system requires a two-person method or a pressure bleeder. Work from the farthest caliper (right rear) to the nearest (left front). Use 1 liter of high-quality DOT 4 fluid to ensure all old fluid is flushed.

The Bed-In Procedure

The final step is critical for performance and longevity. The pad material and rotor surface need to be mated. Find a safe, open road. Perform 10 to 15 moderate stops from 40 mph to 10 mph, allowing roughly 30 seconds of driving between stops to cool the rotors. Then, perform 6 to 8 hard stops from 55 mph to 5 mph without allowing the vehicle to come to a complete stop. Drive the car for 10 minutes without using the brakes to cool the system down. This process transfers a thin, even layer of pad material onto the rotor, ensuring maximum friction and preventing vibration. A detailed guide can be found on the StopTech bed-in guide.

Comprehensive Cost Analysis

The advertised cost of $2,500 is a solid baseline, but the final figure depends on labor rates, shipping, and potential hidden costs.

Cost Breakdown

Prices for the exact kit can be verified through reputable suppliers such as RallySport Direct, which stocks complete Brembo GT kits for the Evo 8/9 chassis.

Long-Term Ownership Value

Understanding the long-term cost is crucial. Replacement brake pads for a BBK cost more than stock pads ($150-$250 vs. $50-$100). Replacement rotors (the iron braking ring only) cost around $400-$600 per pair, which is significantly less than replacing the full single-piece stock rotors ($300 each) while offering superior thermal performance.

For the track driver, the cost avoidance of boiling fluid or warping rotors is substantial. A brake upgrade is often cheaper than repairing crash damage caused by brake failure. For the daily driver, the BBK offers a significant safety margin and a reduction in stopping distances, which can be a lifesaving upgrade in emergency situations.

Is This Upgrade Right for You?

The value of this investment depends heavily on how the car is used.

For the Track Enthusiast

Yes. This is the single most important safety modification you can make to a high-horsepower Evo 9. The stock brakes will fade within two or three hard laps at most tracks. A BBK allows for consistent, confident braking lap after lap, lowering lap times and increasing safety. The $2,500 investment is cheaper than an engine rebuild caused by an off-track excursion.

For the Street Enthusiast

Conditional. If you drive aggressively on public roads, the improved pedal feel and modulation make the car more enjoyable to drive at the limit. The confidence gained from knowing the car can stop is significant. However, if the car is strictly a daily driver driven gently, the stock brakes with upgraded pads (like Hawk HPS) and stainless lines offer a much better cost-to-benefit ratio for around $500.

Conclusion

The installation of a Brembo Big Brake Kit on the Mitsubishi Lancer Evolution 9 is a definitive upgrade that transforms the vehicle's character. It addresses the car's primary dynamic weakness—thermal brake fade—and replaces it with a system that offers immense stopping power, consistent performance, and excellent pedal feel. At an average total cost of $2,500, it represents a significant financial investment, but one that pays dividends in safety, driving confidence, and track capability. For owners looking to fully unlock the potential of their Evo 9, this is an essential benchmark modification.