TTSPORT Evolution ES4 Rear 4-Piston Big Brake Kit

The TTSPORT Evolution ES4 is a 4-piston brake upgrade kit from the Evolution series, specifically engineered for the rear axle. It is designed to balance braking force when paired with a front big brake upgrade, preventing issues such as insufficient rear braking contribution and an unbalanced overall braking bias. It serves as an ideal rear-end upgrade solution for street driving and light track use.

The TTSPORT Evolution ES4 aims to restore braking balance following a front-axle upgrade. Featuring forged aluminum calipers, staggered-diameter pistons, and two-piece brake discs, it delivers controllable rear braking force, a firmer pedal feel, and consistent, reliable performance on both the street and the track.

1. Caliper Technical Specifications

The ES4 utilizes a two-piece forged aluminum alloy opposed 4-piston caliper. Its piston area and structure are optimized for rear-axle load characteristics; the forging process yields a superior stiffness-to-weight ratio, resulting in minimal deformation under high-pressure braking and clearer pedal feedback.

Piston Layout: Staggered diameter design featuring two pistons per side (28mm and 32mm diameters), totaling four opposed pistons; the total piston area per caliper is 28.4 cm². This area is specifically tuned for rear-axle operating conditions, providing enough force to supplement rear braking without being so aggressive that it causes premature rear-wheel lockup or disrupts the factory ABS and vehicle stability system's braking bias.

Piston Structure: Two-piece heat-insulating pistons equipped with dust boots and high-temperature oil seals. This design reduces heat transfer to the brake fluid, mitigating pedal feel degradation during repeated braking, while also resisting corrosion from road dust and salt to extend maintenance intervals.

Physical Specifications: Caliper dimensions are 255mm (L) x 139mm (W) x 74mm (H), with a net weight of 2.8kg per caliper (excluding brake pads). The exterior features a high-temperature, glossy finish that offers excellent corrosion resistance. Mounting Structure: Radial mounting design featuring vehicle-specific CNC-machined carbon steel brackets, engineered to match the rear knuckle specifications of various vehicle models.

Exterior Colors: Available in seven standard caliper colors—red, fluorescent green, orange, black, silver, yellow, and blue—with options for custom colors and logos.

2. Brake Disc and Pad Configuration

Brake Disc Specifications

All models come standard with 28mm-thick, two-piece internally ventilated brake discs. Multiple diameter options are available, with a choice of two materials: heat-treated high-carbon cast iron or carbon-ceramic (CCB).

Series	Evolution Series
Model / Application	ES4
Axle Position	Rear
Piston Count	4-piston
Piston Type	Two-piece heat-insulated pistons with dust boots
Piston Diameter	28 mm × 2 / 32 mm × 2
Total Piston Area	28.4 cm² per caliper (all pistons combined)
Caliper Dimensions	L 255 × W 139 × H 74 mm
Manufacturing Process	Two-piece forged aluminum body
Net Weight	2.80 kg per caliper (without pads)
Surface Finish	High-temperature gloss coating
Recommended Wheel Size	18 in or larger
Recommended Rotor Size	Ø345–380 mm × 28 mm
Brake Rotor Options
Rotor Option	Iron Rotor	Carbon-Ceramic Rotor
Rotor Material	Heat-treated high-carbon cast iron	Carbon-ceramic composite
Axle Position	Rear	Rear
Rotor Dimensions	Ø345 / 355 / 380 mm × 28 mm	Ø380 mm × 28 mm
Construction	Two-piece assembly	Two-piece assembly
Ventilation	Internally vented	Internally vented
Rotor Mounting	Fixed	Floating
Directional Design	Yes — left/right specific	Yes — left/right specific
Rotor Face Pattern	Curved slot / Grain slot / Wave slot / Drilled and slotted	Cross-drilled
Brake Pad Options
Pad Option	For Iron Rotors	For Carbon-Ceramic Rotors
Compatible Rotor Material	Iron / steel rotors only	Carbon-ceramic rotors only
Operating Temperature Range	0–600 °C	0–700 °C
Average Friction Coefficient	μ ≈ 0.38	μ ≈ 0.45
Lines
Brake Line Construction	Three-layer construction
Brake Line Material	PTFE inner liner / SUS304 stainless braid / PVC protective sheath
Brake Line Function	Eliminates hose expansion under heavy pedal pressure
Brake-Line Fittings	Caliper-side and chassis-side selected per application
Brackets
Rotor Hat Manufacturing Process	CNC-machined
Rotor Hat Material	High-strength aluminum alloy
Caliper Bracket Manufacturing Process	CNC-machined
Caliper Bracket Material	Carbon steel
Caliper Mounting Type	Radial mount with vehicle-specific brackets
Fitment & Installation
Minimum Spoke Clearance	90 mm
Recommended Wheel Size	18 in or larger
Brake Bias Note	Pair with a matched front BBK to maintain proper brake bias
Bedding-In Procedure	Required before aggressive use

The discs feature CNC-machined high-strength aluminum alloy hats (bells) designed to absorb disc deformation caused by thermal expansion and contraction, thereby reducing the risk of brake shudder.

Specific brake pad compounds are matched to each disc type; official specifications are as follows:

Brake pads for steel discs: Operating temperature range of 0–600°C; average friction coefficient (μ) ≈ 0.38. These offer stable braking performance and minimize excessive disc wear, making them suitable for daily driving and light spirited driving.

Brake pads for carbon-ceramic discs: Operating temperature range of 0–700°C; average friction coefficient (μ) ≈ 0.45. Formulated specifically for carbon-ceramic surfaces, they deliver superior braking force and fade resistance at high temperatures.

Note: Brake pad and disc materials must be matched correctly; mixing incompatible materials is strictly prohibited.

3. Supporting Components and Complete Kit

Core Supporting Components

Braided stainless steel brake lines: Three-layer design featuring an inner PTFE layer, a middle SUS304 stainless steel braided layer, and an outer PVC protective sheath. This design virtually eliminates hose expansion under high pressure, resulting in a firmer brake pedal feel and more direct transmission of braking force. Fittings are vehicle-specific, designed to connect seamlessly to both the caliper and chassis interfaces.

Installation Hardware: Caliper mounting brackets are CNC-machined from high-carbon steel, and disc hats are made of high-strength aluminum alloy; both are custom-manufactured to vehicle-specific specifications. A complete set of mounting fasteners is included as standard.

Standard Kit Contents

The complete vehicle-specific rear brake kit includes:

2 x ES4 forged 4-piston rear calipers (left and right specific)

2 x Two-piece brake discs (in the selected specification)

1 x Set of matching brake pads

2 x Sets of vehicle-specific radial-mount caliper brackets

2 x Aluminum alloy disc hats

2 x Stainless steel braided brake lines

Complete set of mounting hardware and brake pad bedding-in instructions

4. Fitment Requirements and Installation Specifications

Wheel Size Requirement: Minimum 18-inch wheels required; 345mm discs are the baseline for 18-inch wheels, while 355mm and 380mm discs require additional verification of internal wheel clearance.

Internal Wheel Clearance Requirement: Minimum clearance of 90mm is required between the inner wheel spokes and the caliper; wheel offset (ET value), spoke design, and barrel depth affect actual compatibility. Official recommendation is to verify fitment using a dedicated clearance template before ordering.

Braking Balance Requirement: Not recommended as a standalone rear-only upgrade. The ES4 is designed to complement upgraded front big brake systems; pairing upgraded rear brakes with stock front brakes shifts the braking bias to the rear, potentially interfering with ABS and vehicle stability systems and compromising safety. It is recommended to pair this with front big brake kits from the same series (e.g., ES6, EB6) for a complete braking system.

Mandatory Bedding-In Requirement: A proper brake pad bedding-in procedure must be performed before aggressive driving to establish a uniform friction material transfer layer on the disc surface; skipping this step can lead to issues such as brake judder, uneven braking force, and abnormal disc wear.

The ES4 is the flagship rear caliper in the TTSPORT Evolution series, characterized by precise positioning, a compact profile, and accessible fitment requirements. Its primary function is to balance the vehicle's braking force after a front brake upgrade, enhancing rear braking stability and fade resistance during continuous braking, while maintaining a linear and consistent brake pedal feel.

5. ES4 Related Questions

Can the ES4 be used as a standalone rear brake upgrade kit?

The ES4 is designed to balance an upgraded braking system. Installing the ES4 alone—retaining the stock front brake setup—may shift the braking force distribution toward the rear. We recommend pairing it with the matching TTSPORT front Big Brake Kit (BBK) or ensuring your existing front braking capacity is sufficient to match this modification.

How do I choose the right brake disc size?

Select the largest size that fits within your wheels while meeting the 90mm spoke clearance requirement. Larger discs offer greater heat capacity and braking leverage, whereas smaller discs help reduce weight and fit into wheels with tighter clearance.

Should I choose cast iron or carbon-ceramic brake discs?

Heat-treated, high-carbon cast iron discs are the ideal choice for street driving, mountain driving, and most track day events. Carbon-ceramic discs are better suited for enthusiasts seeking ultimate heat capacity, reduced unsprung mass, and extended service life.

What wheel sizes are compatible?

The ES4 is compatible with 18-inch or larger wheels, provided there is at least 90mm of spoke clearance. If you are unsure, please provide your wheel specifications or a wheel profile template before ordering.

Is a bed-in process required?

Yes. A proper bed-in process transfers an even layer of brake pad material onto the disc surface; this is crucial for achieving optimal bite, precise braking control, and preventing brake judder.