Category Archives: JDM

2.5RS, AWD, Drivetrain, Ej20, forester, gc8, Impreza, JDM, Legacy, Subaru, Suspension, UK, USDM

Antilock Brake System For Early Subaru Part 2:

Antilock Brake System for Early Subarus:

ABS Service And Brake Bleeding Procedures:

Antilock Brake System for Early Subarus: The first Subaru rally car the Legacy RS relied upon the bousch/nippon ABS units to perform on the WRC circuit.
Antilock Brake System for Early Subarus: The first Subaru rally car the Legacy RS relied upon the bousch/nippon ABS units to perform on the WRC circuit.

Always check the fluid level of the master cylinder and bleed the wheel cylinders following the procedure listed in the service manual. When the HCU has been removed and/or replaced, the fluid must be drained. Replace the cone screws with bleed screws and attach a hose to drain fluid to a container.

Antilock: ABS Service And Brake Bleeding Procedures: A early Subaru Nippon ABS unit ECU.
Antilock: ABS Service And Brake Bleeding Procedures: A early Subaru Nippon ABS unit ECU.

Use extreme care when performing this procedure to prevent damage to the internal components of the HCU. Do not apply AV signal for more than 5 seconds for each application. If no AV signal is received, it is not necessary to close bleed screw between brake pedal applications.

Antilock Brake System Notes and Cautions:

The ECU on early Subaru ABS systems can only display one trouble code–the lowest numbered code. Correct the fault indicated by the trouble code and recheck ECU for another code. Repeat the self-diagnostic procedure listed above, and the next highest code will be displayed. Refer to the appropriate model year service manual for the trouble codes and corrective actions. While the ABS ECU is in the fault mode, the ABS will go to fail-safe and remain passive under all braking conditions. The brake system will function as a conventional power-assisted system without ABS.

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2.5RS, AWD, Drivetrain, Ej20, ej20G, forester, gc8, Impreza, JDM, Legacy, Subaru, Suspension, Transmission, USDM

Antilock Brake System for Early Subaru Part 1:

Antilock Brake System for Early Subarus:

A variety of antilock brake system (ABS) have been installed in Subaru vehicles since the first systems were installed in the 1990 Legacy.  In the sections that follow, we’ll give you a brief overview of each system and explain proper diagnostic techniques.

Antilock Brake System for Early Subarus: A Subaru SVX ABS system.
Antilock Brake System for Early Subarus: A Subaru SVX ABS system.

Antilock Brake System for Early Subarus:

Early Subaru Antilock Brake Systems:

The original Subaru Legacy Antilock Brake System (ABS) was licensed by Bosch and manufactured by Nippon ABS, Ltd. The system electronically controls brake fluid pressure supplied to the brake system. This control helps to prevent “wheel lockup” during braking on slippery surfaces and emergency situations. The system includes a fail-safe feature, which indicates a malfunction by illuminating the warning lamp. The system is then returned to a conventional power brake system. The four channel system provides accurate individual wheelspeed control and improves the directional stability of the vehicle during braking.

Antilock Brake System (ABS) Components

• Tone wheels (4)

• Speed sensors (4)

• Electronic control unit (ECU)

• Hydraulic control unit (HCU)

• G sensor (manual transmission models)

• Warning lamp

A tone wheel is attached to each wheel hub and rotates at the same speed as the hub. The magnetic speed sensor is mounted in the axle housing. The notched tone wheel acts as a reluctor which modulates the magnetic field of the speed sensor. The tone wheels are individually replaceable.

The speed sensor provides an alternating voltage signal to the ECU. The alternating voltage and frequency corresponds to wheelspeed.

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EJ257, Intercooler, JDM, STi, Subaru, TMIC, Turbo, USDM

JDM Automatic Intercooler STi Switch Install:

JDM Automatic Intercooler STi Switch Install:

Here is the step by step guide to installing the JDM Automatic Intercooler STi switch. For those of you wondering the advantage of upgrading to the JDM automatic intercooler switch is that it essentially works as a on/off switch for the STi intercooler sprayer. So there is no more constant pushing of the sprayer button. Push the button once to turn it on, and again to turn it off. However, it will empty out your intercooler sprayer tank very quickly if you keep it on.

Here is the switch we are going to be installed:

JDM Automatic Intercooler Switch: The JDM intercooler switch that you will be installing.
JDM Automatic Intercooler Switch: The JDM intercooler switch that you will be installing.

1.) Pop out the fuse box panel. The fuse box panel is located underneath and to the left of the steering wheel.

2.) Use your fingers to depress the tab on the button of the button to pop it out.

JDM Automatic Intercooler Switch: The USDM stock STi switch that you will be removing.
JDM Automatic Intercooler Switch: The USDM stock STi switch that you will be removing.

3.) Pull the switch out of the dash.

4.) Depress the tab on the back of the plug to remove the switch.

JDM Automatic Intercooler Switch: USDM STi intercooler switch removed. Get ready to install the JDM switch now.
JDM Automatic Intercooler Switch: USDM STi intercooler switch removed. Get ready to install the JDM switch now.
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JDM, STi, Subaru, USDM, WRX

Lips: V-Limited Lip Subaru WRX STi Install guide:

V-Limited Lip Subaru WRX/STi Install guide:

Today we have for you an installation guide for the STi V-Limited Lip. It is being installed on a 2006 STi, but the procedure will be very similar for a V-Limited Lip installation on any other compatible Subarus.

Give your car that extra bit of JDM styling you’re looking for while adding performance at the same time! Constructed of 100% ABS plastic (the same material as your factory bumper), the V-Limited Lip is securely attached underneath the front bumper by a series of small bolts.
This is one of very few front lips available on the market that actually has a performance aspect too it. The design of the lip allows for an increase in front down force, improving your car’s handling at higher speeds. Don’t be fooled by imitations lips that are made of a hybrid material or fiberglass. These “replica” lips are flimsy and very prone to breakage. Treat yourself to the real thing and order your V-Limited Lip today! Don’t forget to protect your new V-Limited Lip with a rubber lip protector.

1. For this install you will need to get the front end of the car in the air. It doesn’t need to be that high, just enough to get under the front of the car. A jack stand under each of the two front lift points should do, ramps will also work if you have them.

2. First, you will need to mount the lip under the bumper so that it will stay steady while you drill the holes. Remove the plastic clips circled in the picture (three more on other end of bumper). Attach the lip to the bumper, but do not reattach the plastic cover’s flaps to the bumper as they were before.

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AWD, Ej20, ej20G, Intake, Intercooler, JDM, Legacy, Rally, Subaru, TMIC, Tuning, Turbo, UK, wrc

Legacy: 1989-1994 Subaru Legacy (BC/BF) GT/RS

Prior to the Legacy RS turbo, Subaru had never enjoyed the experience of distributing a genuine performance car. Of course, there had been the 4WD turbo RX and Vortex, but neither could crack 10 seconds for the 0-100km/h sprint – although they were very reliable. The RS was the gun version of the first Legacy series released in 1988 and discontinued in 1994. The RS (Rally Sport) model was aimed squarely at world rallying, with many of its components and concepts carried over to the dominating Impreza WRX.

Legacy: The BC/BF is unique in having an Air - Water intercooler with a front mounted radiator for optimal cooling. The bonnet scoop only provides cooling to the turbo. While later model legacy's have all used air to air intercoolers.
Legacy: The BC/BF is unique in having an Air – Water intercooler with a front mounted radiator for optimal cooling. The bonnet scoop only provides cooling to the turbo. While later model legacy’s have all used air to air intercoolers.

The center Viscous LSD on the MT models initially starts out with a 50/50 torque split, front and rear, and will up the ratio towards the end with more traction. The manufacturer doesn’t give a final figure, so the max split is either 65/35, or could even venture as high as 95/5, since the A/T model has a different system that is marketed at a 65/35 maximum split. A higher ratio would explain some of the handling characteristics at the limit. The rear differential is also a Viscous LSD model.

The BC/BF is unique in having an Air – Water intercooler with a front mounted radiator for optimal cooling. The bonnet scoop only provides cooling to the turbo. While later model legacy’s have all used air to air intercoolers.

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Ej20, ej20G, EJ257, JDM, TMIC, Tuning, Turbo, USDM, WRX

Turbo: STi/WRX VF Series Turbocharger breakdown:

Turbo: STi/WRX VF Series Turbocharger breakdown:

IHI VF Series
The numbering on both the VF turbos are for reference purposes and not necessarily indicative of its ‘performance’. On GC8/GF8 WRX STi, the VF turbos have gone ‘smaller’ from VF22 to 23, 24, 28, 29 while the release of the New Age STi GDB saw the introduction of a new breed of VF turbos with a bigger compressor wheel namely, VF30, VF34, VF35 for example. The previous VF turbos (VF22,23,24,28,29) have been ball bearing cored while the later ones (VF30, VF35) are Divided Thrust Bearing type core, with the VF34 being a Ball Bearing.

IHI VF22
(455cfm at 18.0psi, 250-325whp, Bolt-On)
The VF22 has the largest potential for peak horsepower. In other words, in the IHI model range, the VF 22 supports the highest boost levels. With its significantly increased turbine housing, the VF22 turbo is capable of producing upwards of 310 whp* on an EJ20. The downside of this turbo is the older center cartridge design and larger compressor housing, which makes for slower spool up but more top-end than the other VF series turbos.

This turbo is the best choice for those who are looking for loads of top end power. The top end power however, does not come without a cost. The VF22 spools significantly slower than the rest of the IHI models due to the larger P20 exhaust housing and is much less suited for daily driving than some of the other models. Although the largest VF series turbo, the VF22 is not quite optimal for stroked engines or those who wish to run more than 20PSI of boost.

The VF22’s compressor is rated at 35 lbs/minute. The VF22 was designed with the EJ20 in mind but because it has the biggest turbine in the IHI family it can be use on the EJ25 with a slight increase in performance. The VF22 is good for around a realistic 300 to 315 WHP on a 2.0L. The IHI VF-22 turbo is the largest of the VF-series turbos.

VF22: The IHI VF-22 turbo is the largest of the VF-series turbos.
VF22: The IHI VF-22 turbo is the largest of the VF-series turbos.

IHI VF34
(440cfm at 18psi, 250-325whp, Bolt-On)
The VF34 is nearly identical to the VF30, with the same exhaust housing and compressor. However the VF34 goes back to the ball bearing design, and in doing so achieves full boost approximately 500RPM sooner than the comparable VF30. The VF34 is the most recent IHI design and as such costs slightly more than its counterpart.

Top end performance and maximum output are identical to the 30. The VF34’s compressor is rated at 35 lbs/minute but the turbo suffers from the same turbine restrictions found with the VF30. The VF34 was designed with the EJ20 in mind and will not have the same performance on an EJ25. The VF34 is good for around a realistic 290 to 305 WHP on a 2.0L.

VF34: The VF34 was designed with the EJ20 in mind and will not have the same performance on an EJ25. The VF34 is good for around a realistic 290 to 305 WHP on a 2.0L.
VF34: The VF34 was designed with the EJ20 in mind and will not have the same performance on an EJ25. The VF34 is good for around a realistic 290 to 305 WHP on a 2.0L.
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EJ257, Intercooler, JDM, STi, Subaru, TMIC, Turbo, WRX

TMIC basics on a Subaru WRX/STi

TMIC basics on a Subaru WRX/STi:

The primary purpose of a top mount intercooler is to reduce post turbo air temperature prior to entering the combustion chamber via the throttle body.

HP gain is around 15HP. This figure can vary as many TMICs replace the restrictive OEM piping and results can be further enhanced with post installation tuning. This is one modification that is extremely difficult to put a traditional HP figure on as results truly vary from car to car based on tuning and turbo output in terms of CFM.

How much HP can my stock TMIC hold? 300WHP on the WRX and 400WHP on the STi are attainable. That does not mean those power levels are 100% efficient, but that those power levels are attainable with their OEM TMICs. As discussed below though, TMICs are not meant to be HP rated, but rather CFM related, but this is an FAQ so the HP figures are given as a good “bad” answer.

TMIC basics on a Subaru WRX/STi: 04-07 STi oem TMIC
TMIC basics on a Subaru WRX/STi: 04-07 STi OEM TMIC

Which manufacturer is best? This topic is highly debated. There have been no reported consistent “bad” TMICs on the market. Obviously, there may have been bad TMICs sold, but not enough to report as “bad” overall.

I have a 2008/2009 model, any differences? Yes. Your engine bay has an entirely new layout vs. the 2002-2007 models.

TMIC basics on a Subaru WRX/STi: A 2008 STi stock TMIC
TMIC basics on a Subaru WRX/STi: A 2008 STi stock TMIC
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JDM, STi, Turbo, WRX

Subaru WRX/STI turbo charger basics

Subaru WRX/STI turbo charger basics:

The primary purpose of an aftermarket turbo is to increase the performance over the stock unit. This can be accomplished by choosing a turbo with better spool, more flow, or a combination suited to the end user’s needs.
TD04 turbo and a VF39 turbo
Subaru WRX/STI turbo charger basics: TD04 turbo and a VF39 turbo side by side

 

Common Terms:
Boost threshold- the lowest RPM at which a turbo will generate positive manifold pressure at maximum engine load.
Turbo lag- the time between hitting the throttle and the turbo providing full boost.

Recommended Reading:
Maximum Boost by Corky Bell is considered by many to be THE publication for turbocharger information.

What is the best turbo? There is no best turbo. Generally speaking, aftermarket turbos fall into these generic categories:
a. Turbos with a little more top end power
b. Turbos with a lot more top end power
c. Quicker spooling turbos

What do all the names and numbers of turbos mean?This link sorts many of them out nicely.

What supporting upgrades are required for aftermarket turbos? At a minimum, aftermarket turbos require a fuel pump, injectors, and engine management for safe operation.

What is my stock turbo?

2002-2008 WRX TD04-13T
2004-2005 STI VF-39
2006-2007 STI VF-43
2008 STI VF-48

Is there a turbo upgrade that does not require other upgrades? Yes. A ported and polished (P&P) stock turbo is an easy upgrade over the stock unit. Though there are many turbos that may be used for short periods of time with a boost controller, it is generally unwise to bolt on an aftermarket turbo with a boost controller.

What is the best turbo with a little more top end? The most widely used turbos meeting this criteria are the VF30/VF34 and the 16G.

What is the best turbo with a lot more top end? The most widely used turbos meeting this criteria are the VF22, 18G, 20G, FP Green and it’s clones.

What is the best turbo with quicker spool? The most widely used turbo meeting this criteria is a P&P stock turbo.

What makes a good autocross type event turbo? The big thing to look for in a good performer for autocross use would be quick spool and more than stock flow. The TD04, TD05-16G, VF34, VF22, VF39, 16G, and 18G can all be considered good autocross turbos, but their particular suitability depends on the type of events where the car is generally run.

During the consultation with your Vendor, discuss in depth the course length, speeds seen, gears used, and other local venue particulars to assist in determining what best suits your needs. A word of caution….before modifying or changing your turbo, be aware that this will have an effect on what class your vehicle can legally run.

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