HKS Exhaust System User & Installation Manual

Confirm Before Installation

Please make sure that the kit has all the provided parts listed below.

⚠️ Be careful when handling this product; avoid dropping or giving it excessive impact. Otherwise, it may result in product damage or improper installation.

Parts List / Hardware

Diagram Description

The diagram illustrates the components of the HKS Hi-Power Muffler exhaust system for the Honda Civic Type-R. It shows the Main Muffler at the rear, connected to the #2 Mid Pipe via a Ring Gasket (D60). The #1 Mid Pipe connects to the #2 Mid Pipe with a Ring Gasket (D75). The #1 Mid Pipe then connects to the stock front pipe using a Gasket 3-Hole. The system includes Hook Assy L and Hook Assy R for mounting, supported by stock rubber stays. Various hardware, including bolts (M10 P=1.5 L=25), nuts (M10 P=1.5), spring washers, and flat washers, are used for connections. An Actuator is also depicted, likely for controlling an exhaust valve.

Foreword

Thank you for purchasing the HKS exhaust system. Please read this User & Installation Manual thoroughly before using this product so that you will understand and use the product correctly. Please confirm that the contents are correct before installation on the vehicle.

Important Considerations:

• Replacing exhaust systems is dangerous work best performed by mechanics with specialized training in an automobile service shop. Untrained customers installing an unfamiliar product risk injury or severe burns. Request a specialist service shop for installation.
• Do not perform illegal modifications such as cutting pipes or removing internal muffler components.
• HKS is not responsible for product breakdown or damages resulting from modification, disassembly, or misuse by the customer or a third party.
• Product and parts may be revised without warning.
• Due to regulations, it is illegal to drive any vehicle with the catalytic converter or other emission devices removed or modified (unless specified by local regulations).

Product Precautions

• The exhaust manifold, exhaust pipe, catalyst, and muffler become extremely hot when the engine is on or immediately after it stops. Avoid touching sections exiting the rear of the vehicle to prevent burns. Clothing could burn or melt if it touches the tail pipe when loading/unloading the trunk. Exercise caution when stopping or parking the car.
• Oil or brake fluid spilled on the exhaust manifold can ignite.
• Exhaust gases contain toxic substances, posing a risk of carbon monoxide poisoning in poorly ventilated areas. Always turn off the engine and ensure adequate ventilation before working in enclosed spaces. Be cautious around pets and children. Note wind direction when running the vehicle near people.
• This aftermarket exhaust improves efficiency and performance. Ensure brakes are fully serviced and perform a safety check on all undercarriage components.
• The system is designed for standard vehicle height. Lowering the vehicle excessively may cause the muffler to be damaged by road surfaces or objects, leading to exhaust leaks.
• Even with correct usage, sound muffling performance may degrade due to toxic substances or corrosion. Consult a dealer or service shop if performance is lost. Corrosion can lead to fire from exhaust gas leaks and fines for a poorly maintained vehicle.
• Drivers are legally responsible for vehicle upkeep. Periodic inspection and service are essential for safety and pollution prevention.

General Precautions

• While HKS uses selected materials and strict quality control, the product may corrode or develop holes early if driven under adverse conditions or hit by road debris. This could cause exhaust gas leaks.
• Removing the catalytic converter or its internal components is prohibited by law and leads to environmental pollution.
• Exhaust components reach high temperatures. Do not park the vehicle over dry grass or flammable materials while the engine is running or immediately after stopping, as this could cause a fire. Park in areas free of flammable objects.
• Avoid prolonged engine revving or idling, which can degrade muffler sound muffling material and cause heat damage to engine compartment electrical parts.
• Do not store the vehicle in humid areas or where salt is prevalent, as this can cause deterioration and corrosion.
• Using the vehicle for racing or circuit runs may significantly lower product durability.

Installation Precautions

• Follow all instructions precisely. Use a torque wrench and tighten screws to factory torque to prevent loosening.
• Exhaust manifolds and catalytic converters get extremely hot. Work only after the vehicle has cooled down. Use heat-resistant gloves.
• Rust can make nuts and bolts difficult to loosen. Use a spray lubricant and correct tools, avoiding excessive force that could break them. Always use heat-resistant gloves.
• Exhaust system replacement is typically done underneath the vehicle. Never work under a vehicle supported only by a standard car jack; use a specified lifting machine for safety.
• Replacing an exhaust system involves simultaneous tightening of multiple parts and supporting a heavy system. Working alone is dangerous; always work with two or more people.
• Maintain proper clearance when installing the new system, especially near brakes, fuel lines, drivetrain, and electrical systems.
• Replace any cracked or deteriorated rubber exhaust hangers with the vehicle manufacturer's standard parts.
• After removing the stock exhaust, disassemble it into the shortest possible pieces and store horizontally to allow for moisture dissipation.
• It may be necessary to cut the stock exhaust into two pieces for removal, as it was installed before the rear suspension.
• The HKS exhaust system bolts directly on and requires no modification to the vehicle or the system itself.

Installation Procedure

Please follow the automobile manufacturer's work procedures when removing stock parts. "Stock parts" refers to the manufacturer's genuine parts.

1. Remove Stock Parts

1. Remove the stock rear undercover, mid pipe, and main muffler according to the automobile manufacturer's instructions.

2. Installation of the Actuator

ℹ️ NOTE: The supplied actuator must be used. If the stock motor runs dry or is removed, an error code is recorded. The supplied actuator reproduces the mechanism of the stock valve, and using it will avoid the error code.

1. Remove the stock motor (Fig. 1) from the stock muffler. Do not remove the spring attached to the motor as it will be reused.

   Fig. 1 Stock Motor: A photograph showing the original electric motor unit removed from the stock muffler, which contains a spring that will be reused.

   Fig. 2 Actuator: A photograph showing the new actuator unit provided in the kit, with slots designed to receive the spring from the stock motor.

2. Align the spring of the stock motor with the spring slots on the actuator (Fig. 2) and attach the stock motor to the actuator using the supplied cap bolts (M5).

   Tightening Torque: M5 T= 3.0 N·m (T= 0.3 kgf·m)

   ⚠️ CAUTION: Be careful not to over-tighten the bolts, as tightening beyond the required torque may result in damage to the bolt fixing parts of the motor.

3. Install the Actuator to the subframe using the supplied bolts (M10), spring washers, flat washers, and flange nuts, referring to Fig. 4 and 5.

   Tightening Torque: M10 T= 29 ~ 34 N·m (T= 3.0 ~ 3.5 kgf·m)

4. Route the wires and connect to the coupler as shown in Fig. 4 (enlarged figure) ①. After connecting the coupler, check that the connector is locked.

   ℹ️ NOTE: After connecting the coupler, check the motor's initial operation visually. Initial operation may take a few minutes. If it works, the motor can be used without any problem. If the motor does not operate, check the vehicle condition using diagnostic equipment to see if there are any motor-related problems.

   Fig. 4 Actuator mounting position: This figure shows the location where the actuator is mounted on the vehicle's subframe. It includes a view from the bottom of the vehicle and an enlarged figure highlighting the mounting point labeled ①. A separate inset shows the connection of the wiring coupler.

   Fig. 5 M10Bolt, Flange nut mounting position: This figure illustrates the specific positions for mounting the M10 bolts and flange nuts on the vehicle body, viewed from the right side.

3. Temporary assembly of #1 Mid Pipe

1. Align the #1 mid pipe in the correct position, and insert the stock rubber stay into one of the hooks for hanging.
2. Insert the supplied gasket (3-Hole) between the rear flange of the stock front pipe and the front flange of the #1 mid Pipe. Install the stock flange nut from the opposite side and tentatively fit it.

   ℹ️ NOTE: Reuse stock flange nuts.

4. Temporary assembly of #2 Mid Pipe

1. Align the #2 mid pipe with the proper position, place a ring gasket (D75) between the rear flange of the #1 mid pipe and the front flange of the #2 mid pipe, insert a flat washer into the attached bolt (M10) and pass it through from the front side, then from the opposite side install the attached flat washer, spring washer, and nut in this order for tentative fitting.

5. Temporary assembly of Main Muffler

1. Temporarily assemble the Hook Assy L and Hook Assy R to the main muffler. Put a flat washer on the supplied bolt and pass it through from the front side, then install the supplied flat washers, spring washers, and nuts in this order from the opposite side and temporarily assemble.
2. Fit the stock rubber stays to the four hanging hooks on the Hook Assy.
3. Put the supplied ring gasket (D60) between the rear flange of the mid pipe and the front flange of the main muffler, insert a flat washer into the supplied bolt and pass it through from the front side, then install the supplied flat washer, spring washer, and nut from the opposite side in this order for temporary assembly.

6. Assemble the entire system

1. Check the positional relationship of each pipe and muffler, the clearance with the floor, cross member, and other peripheral parts of the car, and the misalignment of the gasket between flanges. Tighten the temporarily tightened bolts and nuts in order from the front side of the car with the specified torque.

   Tightening Torque: M10 T= 29 ~ 34 N·m (T= 3.0 ~ 3.5 kgf·m)

   * The ring gasket cannot be reused because it will be deformed when tightened with the specified torque.

2. Install the stock rear undercover.
3. Check the alignment and clearance (approx. 14mm) between the tail pipe and the bumper. If there is any defect, retighten from the beginning. If insufficient clearance is left unchecked, abnormal noise may be heard, and resin bumpers may melt due to heat.

7. Verifying a Correct Installation

1. Check the clearance for each section by shaking the muffler after installing the product.
2. Start the engine, idle for a while, and rotate up to approx 2500 rpm. Then, inspect that there is no leaking of exhaust air and abnormal sounds from the flange at each section.
3. Drive for a while, then inspect that there is no leaking of exhaust air and abnormal sounds from the flange at each section.
4. If there are any problems found in steps (1) to (3), reinstall the product from the beginning.