Category Archives: EJ257

Ej20, EJ257, Impreza, Intake, Intercooler, STi, Subaru, Turbo, WRX

Intake pipe turbo subaru FAQ

Intake Turbo Subaru

The primary purpose of an aftermarket intake is to increase the amount of air flow the engine receives.

HP gain is 0-15HP. These HP figures are a range as different intakes have different dyno results.

What is an aftermarket intake? Aftermarket intakes can be broken down into two types:
1. Short ram: AKA shorty or ram pod.
2. Cold air intake: AKA CAI.

What does the stock intake look like? To gain a perspective on how aftermarket intakes function, the stock intake features will be shown and discussed for further clarity.

This is the stock intake as viewed from the driver’s side.
The “U” shaped assembly and the tank that connects to it on the left is commonly referred to as the snorkel,  silencer, or resonator. It is actually hidden in the fender.

Stock Subaru turbo intake piping.

This is the stock intake as viewed from the passenger’s side.

This is the stock intake as viewed from the passenger’s side.

This is the stock intake as viewed from above.
1. Stock “ram intake” funnel.
2. Stock air filter box.
3. MAF sensor.
4. MAF sensor piping.

This is the stock intake as viewed from above.
1. Stock “ram intake” funnel.
2. Stock air filter box.
3. MAF sensor.
4. MAF sensor piping.
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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

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
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EJ257, Impreza, Intercooler, STi, Subaru, Turbo, WRX

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.

 

Remove 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.

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.
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AST Coilovers, AWD, BBS, brembo, DCCD, EJ257, Impreza, Obsidian Black Pearl, STi, Subaru, Turbo, UK, USDM

2nd Generation Subaru Impreza WRX STi United Kingdom varients

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.

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AWD, EJ257, Impreza, STi, Subaru, Turbo, WRX

THE THIRD GENERATION SUBARU 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.

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AWD, BBS, brembo, DCCD, EJ257, Impreza, STi, Subaru, USDM

The second generation Subaru Impreza WRX STi

Subaru Impreza WRX STi winter driving.

Second generation (2001 – 2007)
Second generation (GDB-F)
Production 2001-2007
Body style(s) 4-door sedan
4-door station wagon
Engine(s) 2.0L H4
2.5L H4
Transmission(s) 6-speed manual
5-speed semi-automatic
Wheelbase 2004-05: 100.0 in (2540 mm)
2006-08: 99.4 in (2525 mm)
Length 2004-05: 173.8 in (4415 mm)
2006-08: 175.8 in (4465 mm)
Width 68.5 in (1740 mm)
Height 56.3 in (1430 mm)
Curb weight 3,296 lb (1,495 kg)
Related Subaru Impreza
Subaru Forester
Subaru Impreza WRX
Saab 9-2X
In 2001, the Impreza line received a complete update. The chassis was stiffened so that it had 120% torsional stiffness increase. The WRX STi gained 17″ x 7.5″ alloy wheels over the previous 16″ x 7″ wheels. The 5 speed manual transmission (reputed to be one of the car’s weakpoints) was changed to an STi engineered 6 speed manual transmission. The engine was retained from the Version 6 STi and still retains the semi-closed deck block and is still labeled as the EJ207, However, the turbochargers are IHI models. The interior was updated with a STi logo on the gauge. The STi’s tachometer also has a red shift light. The STi’s and optioned Type RA STi have received Brembo 4 piston front and 2 piston rear brakes while the bare-bones Type RA STi still carried the Subaru 4 piston front and 2 piston rear brakes. Externally, the STis had larger hood scoops and had foglight covers with STi embossed on them. The DCCD was updated so it can work with anti-lock brakes. During braking, when the ABS is on, the DCCD will set itself to open-mode (no locking).

The version nomenclature was dropped from the name. Japanese and other auto-enthusiasts often refer to the chassis as GDB/GDF (the STi has a ‘B’ or ‘F'(for USDM models) where as the regular WRX had an ‘A’). The fourth character of the VIN gives the revision (A to F where G is the 2007 version).

For quick and easy reference to the different exteriors, Subaru Impreza owners use nicknames based on the headlights. Each relates to a creature that has similar looking eyes: 2002-2003 are ‘bug eyes’ / 2004-2005 are ‘Tear Drop’ or ‘blob eyes’ / 2006-2007 are ‘hawk eyes’.

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EJ257, STi, Turbo

EJ257 Block info

So you bought an EJ257 block to build on the side. The seller says it’s “good” and “was running.” I mean, they can say anything, right? That is until you pull the engine block apart and the crank suffered major rod bearing damage from either oil starvation or debris from other failing components.

Here we go to look at the bore housings of the main bearings on the engine block. They look perfectly round to the eye but only measuring tools will reveal how oval they really are. Heat isn’t your friend and is the major cause in warping the bore housings. Rod bearing failure will cause excessive heat if driven on. Even brand new blocks from Subaru can be out of round.

The pictures show the honing marks after a pass on the honing machine. You can see where the color is more dull and has minimal light reflection. There was no contact there with the honing stones. You can see the dark defining line, which was where the bearing sat. Half of the bore housing number 3 (middle) didn’t make contact while honing as with bore housing number 4, which did not make any contact except where the block halves met.

What do we do now? The issue here is you’ll have bearing clearances that are too small or too large. This will cause oiling issues to areas where they most need it. Also the warped mains will not be straight. This can cause bearing to crank journal contact. So when looking at a block to buy, ask about the block’s history. If the seller has the block apart, look for yourself before purchasing. An experienced machine shop that has an align hone machine will be able to straighten the bearing housings as long as they aren’t too out of round.

EJ257 honing Marks
EJ257 honing marks