Modifications So Far

Over the years, we have owned the car, we have made some modifications. As with most things they have evolved over the years, as the quest of more power and handling continued.

Lets start with the specification as it left the dealer in Supporo Japan.

Original Specifications

Description Value
room length1,820mm
room width1,385mm
room height1,170mm
wheel base2,520mm
ride height155mm
curb weight1,200kg
number of seats5
standard weight1,475kg
minimum turn circle5.2m
engine modelEJ20
engine spechorizontally opposed 4-cylinder DOHC intercooled-turbo, cast alloy pistons, sodium exhaust valve, intercooler water spray
cylinder 92.0mm x 75.0mm
displacement 1.994 litres
compression ratio8.5:1
horse power 275HP@6970rpm
torque 235lb/ft@4,070rpm
fuel supplyEGI+MPI
fuel capacity 60 litres
fuel type 100 Octane Min
transaxle close ratio quick shifted 5-speed manual
drivetrain mechanical limited - slip centre differential system, mechanical limited - slip rear differential
Gear Ratios
Final Drive 3.900
steeringrack and pinion, force-sensitive hydraulically assisted
suspension struts
brake system dual-circuit, power-assisted 4-wheel internally vented discs, 2-piston floating calipers
wheelscast alloy 16" 7JJ+53mm
tires 205/50R16 bridgestone



First modifications to the car was to fit 16" alloys from the newer Impreza's this was for no reason other than cosmetic and as the original 15" wheels were fitted with Snow tyres it seemed a good reason to change.

We were happy with these for a while until I spotted a car with 17" Raceline RL7 fitted. Well a few years later the owner decided to sell the wheels, I just had to have them.



The car came with "2 Pot" brakes as standard, and these were found to be a little lacking once I tried a few fast road runs. To start with I fitted "4 Pot" brakes from a P1

Soon we found that even this setup was a bit lacking and we fitted EBC Redstuff II Pads and EBC Disks to match. These proved fine on the road, but once on track they overheated and disintegrated quite quickly, the discs warped soon afterwards. These were removed and a set of black diamond disks were fitted along with upgraded Mintex 1166 compound pads and that helped a lot

The chance came along to get a set of AP 4 Pot calipers along with 13" disks. These were fitted along with a set of braided brake hoses. So far on track I haven't managed to get these to fade.

To help things out on the brake front, I fitted a MRT brake support bar, to prevent the bulkhead, with the brake cylinder, flexing when braking. It may look simple, but it does help a great deal.



The engine itself hasn't had a lot of changes, the main things have been fitting a Blitz induction kit,

Along with a home made cool air box, to stop heated air from the engine bay reaching the filter

When it became time to replace the clutch, rather than fitting a standard replacement, I decided to fit a AP Clutch as an alternative.

As standard the Impreza re circulates the excess air, when the throttle is closed, back into the intake. As an alternative I decide to fit a "vent to air" dump valve. I find that this helps the turbo keep spinning when the throttle is closed, resulting in boost being available sooner when you re-apply the throttle I first fitted a Trans Auto Sport dump valve, taken from my Legacy.

But when the rubber diaphragm split, it was replaced with a Forge item, this has the ability to be "Tuned" to your car's needs, by changing the spring, and adding shims to the valve.

As the Standard car only boosts to around 0.9 Bar, I fitted a Dawes Device to allow me to control the boost manually. It was set to 1 bar, and allowed the car to produce higher pressure quicker that the standard set-up,

One of the stories surrounding many Japanese cars, is the fact that the standard earthing wire's aren't very good. So I decided to make my own earthing kit, to try to produce a better earth connection. A distribution block connected to the battery, has wires leading to the following points, ECU mount, Alternator, inlet manifold, and both suspension towers.

The standard fuel pump on the car failed one day, and was replaced by a FSE hi-volume pump, this will allow me to run higher fuel pressure without the risk of the pump being un-able to cope. Also I fitted a home made surge tank, that restricts the movement of petrol around, during hard corning. Preventing a common Impreza problem of fuel surge, when the inlet to the pump is exposed and sucks in air instead of fuel.

A home made radiator duct was fitted to help the air flow thru the radiator, rather that flow around it, to prevent any over heating of the car.

In the latest round of modifications I decided to remove the inlet manifold and fit some spacers made by Carl Davies. With these I hope to stop the transfer of heat to the manifold, and also allow a bit more space, if I decide to fit a front entry turbo later.

The original fuel pipe set up is serial feed, this means that sometimes the injector on number 3 cylinder receives slightly less fuel. By cutting the original pipes, it is possible to change the fuel to a parallel set up.

A SX Fuel Pressure regulator was fitted when the car was converted to have parallel fuel rails. Pressure was set to 2 bar with the vacuum pipe disconnected.

Whilst the manifold was off the car I took the chance to remove the straight edge of the throttle body inlet, thin the butterfly, and fit smaller screws, all to help a little more air into the engine.

Also in an attempt to bring the inlet temperatures down, an intercooler from a V5 Sti was fitted. This meant quite a bit of work. Firstly the existing dump valve mount was blocked off and a new pipe was welded to the opposite side to allow a dump valve to be fitted at that side. The lip on the rear bulkhead needed to be slightly modified to allow the intercooler to sit low enough to clear the strut brace.

In an effort to reduce weight at the front of the car, a battery from a Subaru Justy was fitted (028). This weights half the weight of the standard (05) battery and I have found no problems with the car sitting unused for weeks, with the alarm on.



The exhaust system on any car, is quite restrictive. Having to meet both noise and emissions regulations, with the aid of catalytic converters and baffled silencers. I fitted a Magnex exhaust system, having only the one silencer at the rear, and no cats.

It was connected to a Falkland Performance de-catted front pipe. The only draw back is that the car fails any emissions testing done, like that in the MOT, and needs to have a cat section fitted when needed. So far I have had no problems with the noise, apart from setting off certain car alarms when I pass.

Hear the exhaust here



The handling on the Impreza is very good to start with, to tighten things up more, I fitted a set of Whiteline solid droplinks to the rear of the the car, and poly bushes to the front anti-roll bar.

I did fit a set of Tein coil-overs to the car, but have removed them when I found that they needed re-building. At the moment the car is on a standard suspension system.

But not for long. A set of Eibach Pro-Street coil-overs were fitted to the car. Still haven't covered enough distance to tell you how they are.



The lights on a standard impreza are know to be very poor, so to help a little I fitted a pair of Hella Comet 500 driving lamps to the blank space where the fog lights would be on a standard car.

Soon afterwards I fitted a pair of Morrette Quad headlights to improve things further, so now 6 lights where there used to be 2.

Interior / Exterior


A set of pedal cover from one of the new model of impreza was fitted, both for look, and to improve the grip on the pedals.

A knocklink was fitted to monitor any detonation in the engine, cause by the petrol igniting too early in the cylinders. A common problem on imported cars running on lower than expected octane fuel.



A set of DTM style mirrors have been fitted, they don't help the rearward view, but do reduce the fontal area of the car quite a bit.


The Dash was made a bit brighter by fitting a polished aluminium trim

Extra information was provided by fitting a Auto Gauge oil pressure & boost gauge to the A pillar

A set of Sabelt 4 point harnesses were installed to hold the drive in place during spirited driving.

My old Momo steering wheel was fitted to this car, having been in several of my cars over the years.

Just to be on the safe side, due to how low the car is now, I fitted a sump guard to the front of the car, just to prevent any damage to the bottom of the engine


Rolling Road Graph

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