Category Archives: STi

VF39 STi turbocharger onto your WRX/Forester

VF39 STi turbocharger onto your WRX/Forester:

Swapping a STi VF39 turbocharger onto your WRX/XT is really easy. Find out here the step by step process on swapping a VF39 onto your Subaru WRX/XT.

You can buy a brand new VF39 Turbocharger here:

Subaru 14411aa5729L Turbocharger

A lot of people seem to be getting hung up on the oil return lines and coolant lines. The coolant lines and banjo bolts from the TD04 ARE interchangeable if your vf39 doesn’t have them (mine didn’t). The oil return line is not and must be modified in order to fit the vf39, (mine had it). Or get a new one from the dealer. I will explain in the pictures when I get to these items.

First remove the intercooler, pretty self explanatory there are 2 bolts that it mounts to, 2 on the BPV and the hoses. Done Deal. Next the heat shield. You should be somewhere around here:

VF39 STi turbocharger onto your WRX/Forester: Start removing the head shield and downpipe.
VF39 STi turbocharger onto your WRX/Forester: Start removing the head shield and downpipe.

 

Remove the downpipe:

VF39 STi turbocharger onto your WRX/Forester: Start removing the downpipe.
VF39 STi turbocharger onto your WRX/Forester: Start removing the downpipe.

Then remove the bolt for the oil inlet (top of the turbo), and start removing the coolant lines (2 lines coming off the side of the turbo 1 goes up 1 goes down). Be careful as you will lose coolant during this step be prepared to either catch it under the car or plug the line:

VF39 STi turbocharger onto your WRX/Forester: Remove coolant lines and oil lines.
VF39 STi turbocharger onto your WRX/Forester: Remove coolant lines and oil lines.

Then remove the 3 bolts that hold the turbo to the uppipe. Loosen from the intake remove vacuum lines and anything else attached to the turbo and you should be ready to take it off. The hose that the oil return line fits into is directly under the turbo and you should probably just lift straight out. Try to leave the hose where it is and lift the line out.

Now that the turbo is off you can start swapping out the parts you need from the td04. The coolant lines from the TD04 will fit the VF39 however they are attached and too close together to fit directly on the VF39 see pic:

VF39 STi turbocharger onto your WRX/Forester: changing out oil lines.
VF39 STi turbocharger onto your WRX/Forester: changing out oil lines.

Steering wheel Subaru GD/GR STi steering wheel removal

GD STi steering wheel
Subaru Impreza GD STi steering wheel

 

When removing the airbag from the steering wheel, be sure to turn the ignition switch to OFF, disconnect the ground cable from battery, and wait for more than 60 seconds prior to starting work. The airbag system is fitted with a backup power source. If the airbag system is serviced within 60 seconds after the ground cable is disconnected, it may inflate.

When storing a removed airbag module, do not place any objects on it or pile airbag modules on top of each other. If the airbag inflates for some reason when it is placed with its pad side facing downward or under any object, a serious accident may result. Do not drop the airbag modulator parts.

 

REMOVAL

1) Disconnect the ground cable from battery.

  • Use a 10mm socket to do so
  • Please remember that if you have Cobb AccessPort, your real time map will be need to be reflashed after disconnecting the battery

2) Set the tires to straight-ahead position.

  • Do your best to park as straight as possible. We suggest straightening the wheel and driving forward approximately 15ft. Try having a friend help you with this.

3) Remove the airbag.

  • In order to remove the airbag, you will need a T30 TORX bit.
  • You will find the two bolts on the left and right-hand side of the steering wheel, approximately at 9 and 3 o’clock (refer to figure 1.0 in the “Reference Images” section of this installation guide).
  • These are lightly torque (~5 to 7.2 ft.lbs) and will not come out of the steering wheel.
  • Once these are loosened, you may gently remove the airbag.
  • You will immediately notice the airbag harness. There may be one or two plugs and one ground plug connected to the airbag. The ground is removed with another gentle pull. The main connectors, located on the center of the rear of the airbag, will have either one yellow or one yellow and one pick lock tabs. Use a small flat head to gently pry this upward. Place this yellow lock tab in a safe place (refer to figure 1.2 or 1.3 for applicable model year).
  • Your airbag is now ready to be removed! Please take great care in storing your airbag!

WRX/STi rear wheel stud replacement

WRX/STi rear wheel stud replacement:

Careful cleaning of the threads/lugnuts and using hand tools (AKA NOT an impact gun!) will help prolong the life of your studs. When the day comes though, here’s how to replace the studs in the rear with stock length studs. If you want to replace them with longer length studs (ARP, etc.) you will have to pull the hub entirely and buy new wheel bearings.


Subaru 28365FE001 Wheel Stud

ARP 1007716 Wheel Stud Kit for Subaru

 

Things you will need:
Stock length wheel studs (As Required): NAPA has these for ~$3 a piece. Part # 641-3209
M8x1.25 bolts (2): Home Depot Racing
M8 washers (~6): Home Depot Racing
19mm Socket: Lugnuts
14mm Socket: Caliper bolts
12mm Wrench: ABS Sensor bolt
7mm Allen Key: M8x1.25 bolts
5mm Allen Key: ABS Ring bolts
Hammer: of the BFH variety, for beating on studs that have misbehaved
Telescoping Magnet Tool: Optional, but will make life much easier.

New wheel stud in the freezer.
New wheel stud in the freezer.

Sticking the new studs in the freezer will cause them to shrink slightly and really help you when it comes time to seat them in the hub. Throw them in the freezer before heading out to Home Depot Racing or leave ’em in overnight, just make sure those puppies are ice cold. Leave them in the freezer until you are actually ready to use them.

Remove the two bolts holding the caliper in place using your 14mm socket, and ziptie it out of the way. I have mine attached to the swaybar in this picture.
Remove the two bolts holding the caliper in place using your 14mm socket, and ziptie it out of the way. I have mine attached to the swaybar in this picture.

2nd Generation Subaru Impreza WRX STi United Kingdom varients

Impreza WR1
Impreza WR1

A limited edition of 1000 Japanese MY04 WRX STI‘s with DCCD were exported to celebrate victory in the 2003 WRC drivers’ championship. 500 were sold in Europe, Australia and South Africa as the Petter Solberg edition; the other 500 were further modified by Prodrive and sold in the UK as the WR1. They had 316 bhp (236 kW) and 309.8 ft·lbf (420.0 N·m), an incredible 0-60 mph time of only 4.25 seconds and a top speed of 155 mph (249 km/h) (electronically limited). They were equipped with Prodrive WRX STI springs, Pirelli PZero Nero tires, mesh grilles, special Ice Blue metallic paint and Prodrive PFF7 Pewter wheels. The new ECU and exhaust were not EU-homologated, so they were fitted after registering the car. The retail price was £29,995.

The 2008 Cusco Subaru Impreza WRX STi Super GT

Cusco's Impreza in GT300
2008 Subaru Impreza WRX STi Super GT

The Cusco team have been campaigning a heavily modified STi with a rear drive conversion as required by regulations since the late nineties and having no two-door model available at present, the Super GT committee gave a special permit for them to race with a four-door model instead of a two-door one. The rear drive conversion rule was lifted in 2006, and since then they returned to all-wheel drive with a transaxle gearbox.

GT300
The Cusco Subaru Impreza in 2008.

In 2008, Cusco’s Impreza won the first GT300 race in Sepang. It marked the first AWD car victory in Super GT/JGTC history. Even though they were having very impressive results(with 1 win and 2 podiums) that season, Cuscho announced that they would not participate in the 2009 season as they want \ The performance of Cusco was outstanding even though they were using a 4-door car, it later lead the Super GT committee to officially allow all 4-door model cars to participate the series. The Toyota Corolla Axio followed suit in 2009.

Cusco's Impreza
In 2008, Cusco’s Impreza won the first GT300 race in Sepang. It marked the first AWD car victory in Super GT/JGTC history.

Impreza Second Gen WRX JDM special models

Second Generation Impreza WRX JDM special variants:

This car was an S-series Impreza based on the Spec C. All of the suspension and powertrain parts included STi parts from the STi part catalogue.
Subaru Impreza S202: This car was an S-series Impreza based on the Spec C. All of the suspension and powertrain parts included STi parts from the STi part catalog.

S202
This car was an S-series Impreza based on the Spec C. All of the suspension and powertrain parts included STi parts from the STi part catalog. The interior included special edition yellow seats with red STi logo stitching. A smaller, lightweight AC compressor was fitted to save weight. The brake rotors were gas slotted. The wheels were STi labeled Rays Volk alloys.

Subaru Impreza S203
Subaru Impreza S203

S203
This limited edition Subaru was an S-series Impreza based on the WRX STi. Again it is basically a car with all the STi parts available. It was sold with custom made 18-inch (460 mm) BBS alloys with Pirellis.

The new S204 was released at the end of 2005.
Subaru Impreza S204 render

2004 – 2007 USDM STi breakdown

2004 – 2007 USDM STi breakdown:

A Stock 2005 USDM STi
A Stock 2005 USDM STi

Rev. D (2004)

In 2004, Subaru of America announced it would sell the WRX STi. Subaru Tecnica International’s president said in an interview with Road & Track magazine that he wished to beat the Mitsubishi Lancer Evolution in the US. Thus, each iteration of the US-spec WRX STi is essentially the same as the respective J-spec STi Spec C. All part numbers matched up, including the part-numbers for the glass windows and dampeners.

However, instead of the EJ207, the USA receives the first EJ257, a 2.5 liter version of the EJ207. Unlike the EJ207, it features hypereutectic cast pistons as opposed to the forged pistons in the EJ207. The steering rack is the standard STi’s 15.2:1 instead of the Spec C’s 13:1

2004 – 2007 USDM STi breakdown:

Rev. E (2005)
As with the Japanese-spec C models, US-spec STis received additional rear fender flaring in order to allow an increase in wheel size. The wheel size went from 17″ x 7.5″ to 17″ x 8″. In accordance with the increased wheel width, steering lock-to-lock turns have been reduced. Wheel hub strength was improved. The P.C.D. was changed from 5 x 100 to 5 x 114.3. The Suretrac front LSD in the 04 model was replaced with a helical unit, the rear differential remains the same clutch type unit. Torque split is set at 35/65. In the interior, the Stereo became standard. The badging has been revised and different look was given to the steering wheel, shift knob, HVAC controls, and center console.

2004 – 2007 USDM STi breakdown:

Rev. F (2006)
The US-spec STIs receive the same face lift as the Japanese-spec STIs. Mechanically speaking, the DCCD (Driver Controlled Center Differential) and the engine mounts have been changed. Like the Japanese-spec STIs engine mounts were changed from metal to liquid-filled plastic mounts to reduce vibrations into the car’s cabin. On the largest Impreza forum, North American Subaru Impreza Owners Club (NASIOC), 2006 owners have had issues with these plastic engine mounts.

The manufacturer will replace them, under warranty, if broken, with the 2005 rubber and metal mounts. Later 2006 vehicles were equipped from the factory with 2005 mounts. The center differential is updated with the addition of a mechanical limited slip mechanism to supplement the electromagnetic DCCD. The torque split is changed to 41/59. The 2006 STI weighs approximately 3,350 lb (1,520 kg).

THE THIRD GENERATION SUBARU IMPREZA WRX STI

Impreza WRX STi
Third generation STi

Third generation (2008-present)
Third generation (GR)
Production 2008-present
Body style(s) 5-door hatchback
4-door sedan(2011-)
Engine(s) 2.0L 304 hp (227 kW) H4
2.5L 305 hp (227 kW) H4
Transmission(s) 6-speed manual
5-speed automatic (w/SPORTSHIFT manual mode) (Japan, Hong Kong, Singapore, Indonesia, and Australia only)
Wheelbase 103.3 in (2,624 mm)
Length 173.8 in (4,415 mm)
Width 70.7 in (1,796 mm)
Height 58.1 in (1,476 mm)
Curb weight 3,373 lb (1,530 kg)
Related Subaru Forester
Subaru Impreza
Subaru Impreza WRX

Subaru Impreza WRX STI 2008The 2008 STI has received a higher degree of parts to differentiate it from its Impreza WRX brethren. Unlike the Impreza WRX, the STI uses aluminum suspension components, is only available as a 5-door hatchback, and has different fenders that are 2.2 in (56 mm) wider. It adopted “Subaru Intelligent Chassis Design” and “Dynamic Chassis Control Concept”. The turbo forces air through a larger top-mount-intercooler which has lost the red “STI” that was on previous generations. It is the first generation of this model with an automatic transmission which is able to import to outside Japan.

Like other 2008 Impreza models, the 2008 STI benefits from a lower polar moment of inertia due to smaller overhangs, and also features a double wishbone rear suspension.[16] The car also borrows new intake and exhaust components from the Legacy GT platform.

The latest Impreza WRX STI features Multi-mode Vehicle Dynamics Control (VDC) with “Normal”, “Traction”, and “Off” modes, Subaru Intelligent-Drive (SI-Drive) with 3 modes: Intelligent, Sport, and Sport Sharp (S#), and Multi-mode Driver’s Controlled Centre Differential (DCCD). The DCCD enables driver to select the manual or auto: “auto”, “auto+”, and “auto-” mode in order to distribute the torque based on driving preference or conditions.

Subaru Impreza WRX STI (Japan)The JDM version has a 2.0L 308 PS (227 kW; 304 bhp) EJ207 engine with a Twin scroll turbocharger, while other versions of the car have a 2.5L 300 PS (221 kW; 296 bhp) EJ257 engine with a single-scroll VF48 turbocharger.