Billet Internal Wastegate Actuator for Subaru JDM STI 99-21 Twin Scroll

SINGLE PORT ACTUATORS

Function: Boost reference signal is supplied to one side of the diaphragm and moves the piston in one direction to open the wastegate. Only mechanical spring pressure is used for the return stroke / holding wastegate closed.

Application: Ideal for basic boost control including via manual boost controller (MBC) or electronic boost controller (EBC)

Advantages - simple plumbing & basic functionality

Disadvantages - Heavily reliant on spring pressure to control boost. Typically requires a significantly heavier spring than a dual port for the same boost pressures, narrower range of boost control and less precise.

DUAL PORT ACTUATORS

Function: Boost reference signal is supplied to both sides of the diaphragm for more precise control of the wastegate in two directions - opening and closing. Spring pressure is pneumatically assisted for the return stroke / holding wastegate closed

Application: Particularly well suited to applications with higher boost levels, high exhaust backpressures or oversized wastegates. Typically used in conjunction with an EBC for the ultimate in boost control.

Advantages - Controls the diaphragm bidirectionally, allowing more precise boost control and superior response. Typically a softer spring than a single port actuator is required for any given target boost pressure, providing a greater range of boost adjustment pressures for any given spring installed

Disadvantages - (To take advantage of the secondary port) Added complexity, more plumbing and must be used with an EBC

Tech tip: Dual port actuators give you more flexibility and tunability but can also be run as a traditional single port actuator - just leave the lower actuator port vented to atmosphere.

 

A wastegate is basically a device that bypasses some exhaust flow around the turbine section of a turbocharger to control maximum boost. A wastegate is usually controlled by a pressure actuator that is connected to manifold pressure. The wastegate is normally closed, held shut by a spring inside the actuator canister. When preset pressure limits are exceeded, the actuator progressively opens the wastegate, allowing exhaust flow to bypass the turbine, thus regulating manifold boost pressure. On the surface, it sounds like a simple premise, and in fact, a wastegate is a simple device. The problem comes from the pressure in the exhaust system, called turbine inlet pressure that can bear against the valve, overpowering the spring in the actuator, and forcing the wastegate open at lower than intended boost levels.

The normal type turbocharger wastegate actuators are selected or engineered for a specified boost level and turbine inlet pressure. Such actuators are usually just big enough to do the job at the target boost levels under the 2 bar. If the turbocharger boost is increased for additional airflow and performance, the normal type wastegate actuator is frequently incapable of holding the wastegate fully closed until the higher boost level is reached. This happens because turbine inlet pressure also increases as boost pressure rises. The fix is to use a bigger spring in the wastegate actuator to hold it closed until the desired peak boost is achieved, however, that also requires a bigger actuator diaphragm to override the heavier spring when the desired boost level is reached.

That’s why KINUGAWA created the Big Head actuator that’s used on many of its diesel or high boost level gasoline systems. Available in single or dual port, the Big Head actuator features a wider diaphragm with larger surface area for greater mechanical advantage over the wastegate resulting in increased boost response and more precise control even in extreme applications. The net affect is that the turbocharger comes up to peak boost more quickly and then maintains that boost level throughout the engine’s RPM range for optimum mid-range torque and top end performance.

 

• Quick and Controlled Boost
• Produces massive torque right from idle
• Increases diaphragm area & spring pressure
• Keeps valve seated longer achieving higher peak boost, sooner
• Crisp acceleration and more mid-range pulling power

• 1 x Adjustable Actuator (pre-assembled to selected spring pressure)
• 1 x Turbo-Specific Bracket
• Additional Springs (when selected)
• All necessary nuts/bolts

The internal wastegate actuator is designed to have 2mm of preload applied to the rod during installation. Please ensure that this is set accordingly. For a clevis type application, when installing the onto the wastegate valve arm, make sure that there is 2mm of preload. Then use compressed air - the amount of air pressure applied should be slightly higher than what the Big Head actuator spring is rated to. (do not apply air
pressure supply higher than 3 bar (40psi) gauge).

This is required to pressurize the Big Head actuator so that the clevis can be hooked onto the wastegate valve arm easily.

Remember to reinstall the standard R-Clip or circlip to secure the clevis to the wastegate valve arm. Then tighten the rod nut to secure the clevis onto the rod.

1.WARRANTY POLICIES

If any products are proven to Kinugawa Turbo Systems’ satisfaction to have been defective at the time of sale, We will make an appropriate adjustment in the original sales price of such product or at Kinugawa Turbo Systems’ election, replace the defective product. Kinugawa Turbo Systems shall provide information for limited warranty extended to the consumer of

commodities. Said warranty applies only to “completed” and “unaltered” turbochargers only (spare parts exculded) sold by Kinugawa Turbo Systems; any alterations made to the completed products by any party other than Kinugawa Turbo Systems shall negate such warranty. Warranty shall cover 100% of parts for one (1) year from the date of purchase. All other products sold by Kinugawa Turbo Systems shall be covered by an “exchange” of the same product within seven (7) days from the date of purchase and provided that the product to be exchanged has not been used in any manner.

1.1. For none- Kinugawa Turbo Systems branded and completed turbo units, warranties expressed or implied are represented by the manufacture of the product and not Kinugawa Turbo Systems.

1.2. Kinugawa Turbo Systems warrants to the purchaser of its products that will during the warranty period and subject to the limitations and exclusions comply with all applicable specifications and be free from defects in materials and artistry. Kinugawa Turbo Systems’ liability is limited to the repair or replacement, at our option, of any warrantable product returned prepaid with complete service history, if found by Kinugawa Turbo Systems to be defective in material or artistry. All replacement units shall be rebuilt units similar in quality to the unit replaced.

1.3. Kinugawa Turbo Systems’ warranty shall not apply to any unit that has been improperly stored or installed, subject to misapplication, improper operating conditions, accidents or neglect, or has been poorly repaired or altered or otherwise mistreated in the field. Unauthorized disassembly will void all warranty consideration. TURBOCHARGER WARRANTY SHALL NOT APPLY TO ANY TURBOCHARGER THAT

SHOWS EVIDENCE OF (1) Hot shut down. (2) Insufficient lubrication. (3) Oil Contamination/ Foreign object in lubricating oil. (4) Any damage to either the compressor wheel or the turbine wheel caused by a foreign object. (5) Over-boosting (over Kinugawa turbocharger standard pressure of 1.2 bar or 17psi).

1.4. Kinugawa Turbo Systems shall not be liable to purchaser under any circumstances for any special, incidental or consequential damages, including without limitation, damage to or loss of property other than for turbocharger products; costs incurred in installation, repair or replacement; lost profits, revenue or

opportunity; loss of use; damages resulting from or related to downtime of turbocharger products; the cost of replacement transportation, power or compression; the cost of substitute products; or claims of Distributor's customers for such damages, howsoever caused, and whether based on warranty, contract and/or tort(including negligence, strict liability or otherwise).

1.5. The obligations in connection with the design, manufacture, sale, delivery, and/or use of Kinugawa Turbo Systems’ turbochargers and related parts and/or services shall in no circumstance exceed in aggregate a sum equal to the amount paid to Kinugawa Turbo Systems for turbocharger products subject to customer's warranty claims.



2.TURBOCHARGERS FOR RACING OR COMPETITION USE

2.1 Turbochargers used for any form of racing or competition and/or set to run higher than standard boost pressure are supplied in good faith and on the understanding that no guarantee is given in respect of performance or reliability of the product, either by the manufacturers or Kinugawa Turbo Systems.

2.2 Kinugawa Turbo Systems cannot be held responsible for personal injury or damage caused to the engine or vehicle by a failed turbocharger.


3. OTHER WARRANTY CONDITIONS

3.1 The turbocharger must be fitted to an engine that is in good working order so that the operation of the turbocharger is not prejudiced.

3.2 The engine oil, oil filter, and air filter must be changed at the point of turbocharger fitment, using only components and materials approved by the vehicle manufacturers. In the case of petrol engine turbochargers, Kinugawa Turbo Systems only recommends fully synthetic oil with an SAE rating of 10W-40 or higher and which exceeds the following specifications: SH/CD or CCMC G5/PD2 unless otherwise stated by the vehicle manufacturer. For further information

and advice, please contact our Technical Sales Team.

3.3 The purchasers/installers shall satisfy themselves that all reasonable steps have been taken to ensure that any original cause of turbocharger failure has been eliminated and that the turbocharger is correct for the application,

and is fitted entirely in line with the engine manufacturer’s recommendations.

3.4 Warranty may be denied in the event of either the turbocharger or the engine being modified to increase power output if this modification is prejudicial to the performance of the turbocharger.

3.5 Under no circumstances should a vehicle be used if a turbocharger problem is suspected, as this could cause further damage to the turbocharger and/or engine.

4. LIMITATION AND EXCLUSION OF LIABILITIES

4.1 Kinugawa Turbo Systems Performance Kits are professional aftermarket products only designed for certain racing vehicles driven on particular racing tracks and shall only be used on racing vehicles that will never be driven on public roads or highways. Kinugawa Turbo Systems Performance Kits are not legal for the use in vehicles on public roads or other road to which public road law applies. Any vehicle modifications using Kinugawa Turbo Systems Performance Kits are AT YOUR OWN RESPONSIBILITY and AT YOUR OWN RISK. Only use Kinugawa Turbo Systems Performance Kits in compliance with all applicable laws, regulations and ordinances (including but not limited to emission, noise, operating license, performance, safety and type-approval aspects). A vehicle modification using Kinugawa Turbo Systems Performance Kits may particularly affect or void a vehicle’s warranty, operating license or type-approval. Moreover, only use Kinugawa Turbo Systems Performance Kits in compliance with all applicable racing and racing track provisions. It is YOUR OWN RESPONSIBILITY AND RISK to ensure that your Kinugawa Turbo Systems Performance Kit fits your vehicle and area of application. YOU MUST ENSURE LAWFUL AND SAFE OPERATIONS AT ANY TIME. You should particularly consult the owner’s manual and service manual of your vehicle. You should also contact your vehicle’s manufacturer to determine what effects modifications may have on important aspects such as safety, warranty, performance, etc. Only install and use Kinugawa Turbo Systems Performance Kits if you have fully read and understood this important safety information and if you fully agree with the terms and conditions set forth therein.