Category Archives: Ej20

Ej20, JDM, Legacy, Old School Subaru, Subaru, Turbo

Legacy World Speed Records

Legacy World Speed Records:

Prior to launching the 1990 Legacy, Subaru drew attention to the car’s capabilities and durability by attempting to set world speed records with the Legacy. In an effort involving three Legacy RS Turbo Sedans, Subaru established a new 100,000 kilometer (62,137 miles) world speed record as well as 13 international records. Some of these records still stand today.

Legacy World Speed Records: For the 1990 model year, Subaru was launching the Legacy, a front-wheel drive model with optional 4-wheel drive. It was larger than previous Subaru models and had a 2.0-liter, 16-valve, turbocharged engine.
Legacy World Speed Records: For the 1990 model year, Subaru was launching the Legacy, a front-wheel drive model with optional 4-wheel drive. It was larger than previous Subaru models and had a 2.0-liter, 16-valve, turbocharged engine.

For the 1990 model year, Subaru was launching the Legacy, a front-wheel drive model with optional 4-wheel drive. It was larger than previous Subaru models and had a 2.0-liter, 16-valve, turbocharged engine. Since the car represented a new segment for Fuji Heavy Industries Ltd. (FHI), it wanted to demonstrate the vehicle’s performance, reliability, and durability. Thus began the quest for the 100,000 kilometer (62,137 miles) world record. That represents the distance typically covered during five years of hard driving.

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Drivetrain, Ej20, EJ257, gc8, Impreza, JDM, Legacy, STi, Subaru, Turbo, USDM, WRX

Cool Down WRX Turbo Procedure

Cool Down WRX Turbo Procedure:

It is not necessary to perform a cool down/idling procedure on Subaru WRX turbo models, as was recommended with past turbo models. “The current 2.0 liter turbo engine has a far greater cooling capacity and, coupled with technology advances, makes this practice no longer necessary. This explains why information about a cool down is not included in the Impreza Owner’s Manual.

Cool Down WRX Turbo Procedure: It is not necessary to perform a “cool down/idling” procedure on Subaru WRX turbo models, as was recommended with past turbo models.
Cool Down WRX Turbo Procedure: It is not necessary to perform a “cool down/idling” procedure on Subaru WRX turbo models, as was recommended with past turbo models.

The heat contained in the turbocharger begins to vaporize the coolant at the turbocharger after the engine is stopped. This hot vapor then enters the coolant reservoir tank, which is the highest point of the coolant system.

At the same time the vapor exits the turbocharger, coolant supplied from the right bank cylinder head flows into the turbo. This action reduces the turbocharger temperature. This process will continue until the vaporizing action in the turbocharger has stopped or cooled down.

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2.5RS, Drivetrain, Ej20, EJ25, EJ257, forester, Impreza, STi, Subaru, Turbo, USDM, WRX

Engine noise when cold (Winter is coming)

Engine Noise When Cold:

Beginning with the 1997 model year, the 2.2 and 2.5 engines were made more fuel efficient, more powerful, and were given a flatter, more usable torque curve than in previous years. To achieve these objectives, it was necessary to make improvements and modifications to the Subaru engine lineup. The following are some of those improvements:

• Mechanical valve lash adjusters (reduces friction).
• Lightweight pistons (reduces inertia).
• Short skirt, Molybdenum coated pistons (reduces friction).
• Increased compression ratio (improved power output).
• Improved cylinder head design (improved cooling).
• Improved induction system (improved breathing).

Engine Noise when cold: As a result of these enhancements, some Subaru engines may exhibit some engine noise during the warm-up period after a cold startup.
Engine Noise when cold: As a result of these enhancements, some Subaru engines may exhibit some engine noise during the warm-up period after a cold startup.

As a result of these enhancements, some Subaru engines may exhibit some engine noise during the warm-up period after a cold startup. This engine noise is a consequence of the engine improvements and is not, in any way, an indication of any engine problem.

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2.5RS, Drivetrain, Ej20, ej20G, EJ25, EJ257, forester, gc8, Impreza, JDM, STi, Subaru, Turbo, UK, USDM, WRX

Subaru Engine Block Piston Size Identifier:

Subaru Engine Block Piston Size Identifier:

The picture below of this paragraph shows the location of piston size and main journal size information on all Subaru engines. As the figure illustrates, it is possible to have more than one piston size in the same engine.

Subaru Engine Block Piston Size Identifier: The picture on the bottom shows the location of piston size and main journal size information on all Subaru engines. As the figure illustrates, it is possible to have more than one piston size in the same engine.
Subaru Engine Block Piston Size Identifier:
The picture on the bottom shows the location of piston size and main journal size information on all Subaru engines. As the figure illustrates, it is possible to have more than one piston size in the same engine.
Ej20, EJ257, forester, gc8, Impreza, Legacy, Old School Subaru, Subaru, UK, WRX

SVX POWER STEERING SYSTEMS PART 4

SVX Power Steering Systems on Early Subarus Part 4:

There are two model-specific systems available on SVX vehicles:

SVX Power Steering Systems on Early Subarus Part 4: The engine speed sensitive, or conventional belt driven hydraulic pump and pinion type steering system is standard equipment on the SVX.
SVX Power Steering Systems on Early Subarus Part 4: The engine speed sensitive, or conventional belt driven hydraulic pump and pinion type steering system is standard equipment on the SVX.

• The engine speed sensitive, or conventional belt driven hydraulic pump and pinion type steering system is standard equipment on the SVX.

• An SVX equipped with the SVX Touring Package uses an optional vehicle speed-sensitive system. This system provides normal power assist at low vehicle speeds for reduced driver steering effort, and reduced steering assist at increased vehicle speeds for increased road feel and improved engine operating efficiency. Both systems have many similarities with the Legacy system.

SVX Power Steering Pump

Both systems share many similarities to existing Subaru steering systems. Both use a belt driven power steering pump, although the pump housings are different in appearance.

Rack

A conventional power assisted rack with the standard Subaru lines and hoses is used by the standard system.

Oil Cooler

An oil cooler pipe has been added to both SVX systems. It is located in front of the radiator on the return side of the system.

Rubber Coupler

A steering shaft rubber coupler is used by both SVX systems to reduce road noise and vibration.

SVX Power Steering Pressure Switch

A power steering pressure switch is located on the outlet side of the pump. The switch monitors increased engine load during idle speed steering. The switch provides an input to the MPFI ECU, which prevents stalling by raising the engine idle speed. There is not an additional trouble code for the MPFI ECU.

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Drivetrain, Ej20, forester, gc8, Impreza, Legacy, Old School Subaru, Subaru, WRX

POWER STEERING SYSTEMS ON EARLY SUBARUS PART 3

POWER STEERING SYSTEMS ON EARLY SUBARUS PART 3

Cybrid Power Steering

The Cybrid Power Steering System was standard equipment on the XT6. It’s a computer controlled,
electric motor-driven hydraulic steering system, using a power-assisted rack and pinion assembly similar to the XT. This system provides improved steering feel and more precise power assist over a wider operating range. Fuel consumption is reduced because it requires less horsepower due to the electrically-driven hydraulic pump. The specific system used on the XT6 is quicker than other XT power steering systems, with just 3.2 turns lock-to-lock.

POWER STEERING SYSTEMS ON EARLY SUBARUS PART 3: The Legacy RS used in rallying used the early Subaru power steering system.
POWER STEERING SYSTEMS ON EARLY SUBARUS PART 3: The Legacy RS used in rallying used the early Subaru power steering system.

Cybrid Steering Components

The Cybrid Power Steering System consists of four major components:

• The Motor and Pump assembly mounted on the front bulkhead (firewall).
• A Steering Sensor located inside the vehicle at the base of the steering column.
• A Signal Controller located in the left rear quarter panel.
• The Power Controller mounted on the front bulkhead (firewall) to the left of the Motor/Pump assembly.

Motor/Pump Assembly

The Motor/Pump assembly is similar to a starter motor, since it has an armature, fields, and brushes which are serviceable. The electric motor drives a pump which is very similar in design to an engine driven pump. This combination replaces the familiar belt driven P/S pump assembly. The Cybrid System requires special hydraulic fluid to retain stable viscosity during cold temperatures.

Heater

The Pump incorporates an electric heater to warm the hydraulic fluid in extremely cold operating conditions, improving the steering performance. A thermistor type switch located on a bracket above the Motor/Pump assembly, senses the underhood (ambient) temperature and sends an input to the Signal Controller.

The Heater operates for approximately five minutes after engine start-up. The Signal Controller grounds the heater relay, which passes battery voltage to the heater. The heater relay is located near the motor/ pump assembly.

Note: The Heater only works when the thermometer signals an extreme cold condition.

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AWD, Ej20, ej20G, forester, gc8, Impreza, Legacy, Old School Subaru, Subaru, UK, USDM, WRX

Power Steering Systems On Early Subarus Part 2

Power Steering Systems On Early Subarus Part 2:

Power Steering Rack System

Subaru’s power steering system contains a pump, hydraulic line, and a gearbox (rack). The hydraulic pump is a vane-type pump driven by the engine. It provides pressurized fluid for the system.

Power Steering Systems On Early Subarus Part 2: Subaru’s power steering system contains a pump, hydraulic line, and a gearbox (rack). The hydraulic pump is a vane-type pump driven by the engine. It provides pressurized fluid for the system.
Power Steering Systems On Early Subarus Part 2: Subaru’s power steering system contains a pump, hydraulic line, and a gearbox (rack). The hydraulic pump is a vane-type pump driven by the engine. It provides pressurized fluid for the system.

Oil Pump Operation

The pump has two internal valves: a flow control valve and a relief valve. The flow control valve regulates the volume of power steering fluid delivered to the rack. During high engine rpm, the pressure in the pump overcomes the flow control valve spring. The control valve slides back to close off an oil passage to the rack and to open an oil return port to the pump inlet. This reduces the power assist to the rack during high speeds, improving the steering wheel feel and response.

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Ej20, ej20G, EJ257, gc8, Intake, Intercooler, STi, Subaru, TMIC, Tuning, Turbo, WRX

Overboost and Underboost Subaru common causes:

Overboost and Underboost Subaru common causes:

The common causes for overboost or underboost: This is a basic guide on the possible causes and some solutions to those causes of a overboost or a underboost situation in a turbocharged subaru.

Overboost and Underboost Subaru common causes: This is the layout of the stock turbo subaru boost control system.
Overboost and Underboost Subaru common causes: Turbo Subarus: Common Overboost and Underboost issues with Turbo Subarus.

Overboost:

1.) Decat + High flow induction –  Cure: Reduction of the solenoid duty cycle or alteration of restrictor size will help return boost output to its normal level.

2.) Split, poor fitting, or disconnected pipes – Cure: Replace or refit pipes, the pipes that will cause this issue are between the wastegate actuator, solenoid, and the turbo. Including up to the restrictor on the return pipe of the 3 port solenoid.

3.) Manual Boost Controller – Electronic Boost Controller set too high – Cure: Don’t be so greedy and back the boost duty/adjuster off to a safe level.

4.) Restrictor Pill not fitted / size incorrect – Cure:  Ensure restrictor pill is fitted (3 port) if so on a 3 port reduce the restrictor size and on the 2 port increase the restrictor size to reduce the boost to a safe level.

5.) Clogged 3-port solenoid: It is possible that the flow of air through the 3-port solenoid could be restricted between the turbo outlet port and the wastegate actuator port if the solenoid is very dirty (usually oil vapor from the intake system), this allows the wastegate to remain clamped shut longer than it should be causing a potential overboost situation. Cure: Clean with carb or clutch/brake cleaner.

6.)Loss of solenoid funcation: Although this is not bverboost it shows itself with very simmilar symptoms, its an interesting scenario. It is possible for the solenoid to fail or even stick shut while under boost. This will result in a rapid reduction of boost pressure to wastegate pressure approx 0.5 BAR. So if you were running at full boost 1.0 BAR for example and the solenoid was to fail shut it would feel just like overboost as the wastegate rapidly opens due to the solenoid blocking off the spill from the wastegate. Cure: Either clean the solenoid with carb or clutch+brake cleaner or replace the solenoid.

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