Category Archives: ej20G

Valve Cover Gasket replacement Subaru WRX:

Valve Cover Gasket replacement Subaru WRX:

This is a step by step guide on replacing the valve cover gasket on Subaru flat four engines. This guide will work for most Subaru turbo cars 02-07+ and most other naturally aspirated Subaru cars.

1.) Jack your car up and drain the oil. Remember to put the car on jack stands. You don’t want the car dropping on you.A lot of people do this job with the oil still in the pan, but its better to rather play it safe and drain the oil completely.

2.) Remove the front air scoop. It takes two 10mm bolts.

3.) Remove the nice Cold Air intake box.

4.) After removing all that, you should see this a total of 8 outer bolts and the 2 inner which holds the spark plug coils.

Valve cover gasket: In the center are the two coil packs that need to be removed.
Valve cover gasket: In the center are the two coil packs that need to be removed.

5.) Unscrew them and label them. You don’t want the bolts going into the wrong place. It was a very hard to get any decent clearance so take your time.

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.

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.

22b: First generation Impreza WRX STi special variants

22bRare japanese widebody STi
22b STi

Japanese special variants

22B STi

(03/98 – 08/98)
In 1998, Subaru of Japan produced a widebody, 2-door, Impreza called the 22B STi. The 22B was used to commemorate both Subaru’s 40th anniversary as well as the 3rd consecutive manufacturer’s title for Subaru in the FIA World Rally Championship. On the release of the sales, all 399 sold out from 30 minutes to 48 hours, depending on the report.The cars had the starting VIN code of GC8E2SD. Another 25 were produced for export markets – see the 22B Type UK below.

The 22B had the EJ22 engine as opposed to the regular EJ20 engine. Note: internal Subaru material states the block comes from a V3 EJ20G NOT the EJ22G as most think. Also the intake manifold and heads were from the V4 EJ20K. This means the displacement was increased from 1994 cc to 2212 cc. The block is a closed-deck design. The heads (valves, valvetrain and such) were lifted from the STi Version 4 engine. It produce 350 PS (260 kW; 350 hp) at 6000 rpm and 363 N·m (267 ft·lbf, 37.0 kgf·m) of torque at a lower engine speed of 3200 rpm. The redline was lowered from 8000 rpm to 7000 rpm. The compression is an 8.0:1. The turbocharger is an IHI RHF 5HB (the internal company usage code is VF23).

This car was given a unique color of blue and had fender flared widebody taken from the Peter Stevens designed WRC car, thus widening the width by 80 mm (3.15 inches) for a total of 1,770 mm (69.7). During assembly, a WRX Type R chassis was taken off the line. The fenders were replaced with the 22B STi fenders. The car’s curb weight is 1,270 kg (2,800 lb). The suspension is provided by Bilstein. The brakes were standard 4-piston/2-piston brakes. However, the color is red and the Subaru name cast on the brake calipers and painted white.