PLEASE NOTE THAT DUE TO THE MANY DIFFERENT SPECIFICATIONS OF IMPREZA FROM EARLY 220BHP TO LATE 280BHP VEHICLES, THE POWER OUTPUTS STATED BELOW CAN VARY. THE INCREASED POWER FIGURES SHOWN ARE BASED ON A VEHICLE RUNNING 220BHP AS STANDARD. PLEASE CALL TO CONFIRM THE POWER GAIN FOR YOUR PARTICULAR VEHICLE FOR ANY GIVEN UPGRADE.
Stage 1 upgrade: (15 BHP)
exhaust system (3 options)
Super Drager exhaust 75mm pipework with 115mm tailpipe also removes 2nd catalyst on UK models. Certified to Japanese 'JASMA' noise levels. £545.00 1 hour
Hiper Muffler system. As above but full power designed (also removes 2nd cat.) Not 'JASMA' certified £425.00 1 hour
'Ti-Hiper' exhaust system. This system is very similar to the Hiper Muffler above, but has the addition of a titanium sleeve mounted to the tailpipe. Due to the properties of this material, the tailpipe will alter it's colour depending on heat soak, giving a unique rainbow-like effect at normal running temperature. Sounds a bit odd but actually looks fantastic! £475.00
options:
High flow downpipe 75mm (removes 1st cat.) £135.00 1~2 hours
Full stainless manifold/crossover pipes (equal length headers) robot welded (pictured above left) £1,275.00
HKS have just released their own full stainless manifold for the Impreza!!
Please note: Post 92 models will require the use of at least one catalyst for MOT laws. Stage 2 upgrade: (25 BHP) HKS PowerFlow free flow induction system with built in velocity stack for turbulence free induction. Also removes restrictive resonator box on early models. All models £155.00 1
HKS 'Racing Suction Kit' As with the Lancer EVO, these kits come with polished aluminium pipework, blue silicone joining hoses and are more than 'just' an induction kit!
Only for 1996> models. £255.00. Picture below. Note the aluminium sandwich plate that has come with all HKS Impreza filtration kits since their introdution-this directs airflow correctly through the delicate airflow meter and reduces the risk of airflow meter damage as well as allowing an accurate meter signal to be sent. Be careful of using lesser quality 'bolt-on' filters such as simple 'cones' with no airflow diffuser or supporting bracketry.
NOTE!!!! The Version 5 airflow meter is extremely delicate and utmost care must be taken when fitting any induction kit. Movement of the meter must be kept to an absolute minimum to enable you to get the maximum life from them. They are a known weak point on the vehicle and many meters have failed even when running standard airboxes. Some people believe that fitment of an induction kit will cause the meter to fail. In reality, it is generally the disturbance of the meter itself that causes the problems, not the actual filter.
HKS 'Direct Drive' filter. This filter is designed to bolt directly to the air flow meter, therby keeping installation very simple by not requiring any air-flow meter adapters, silicone tubing/jubilee clips etc. Offered mainly as a 'budget' air filter system for those that want to get rid of the factory air-box but can't quite stretch to a full-on induction system. See picture below. 1996> models only. £77.50
Stage 3 upgrade: (55 BHP) Fuel Cut Defencer (overboost chip) £95.00 1 hour And EITHER: Variable Boost Controller (mechanical) £50.00 1 hour OR: EVC E-Z Electronic boost controller £315.00 4 hours OR: EVC-4 Electronic boost controller £395.00 5 hours OR: Apex'i AVC-R Electronic boost controller £425.00
OR: EVC Pro Electronic boost controller £685.00 6 hours Recommended options: Sequential Dump Valve kit: All models £245.00 1 hour HKS 'Iridium' spark plug set £58.00 set
Stage 4 upgrade: (65 BHP) HKS PFC F-Con piggyback fuel computer pre 97 models £795.00 4 hours HKS AFR (Air Fuel Ratio) module 97 on (For slight increases in fuel supply only) £95.00 1 hour HKS Super AFR for more flexibility of fuelling adjustments. '97 on models only. £275.00 3 hour
option 1:
'UniChip' (fuel & ignition) piggyback ECU. £350.00. (All models). This unit allows us to alter fuel and ignition parameters similar to the F-Con S unit below. However, programming and mapping of the UniChip can take longer so for vehicles that will need radical map altering or ongoing modifications we reccomend the fitment of an F-Con S. For vehicles that require relatively minor fuel and/or ignition re-mapping then the UniChip is an ideal solution.
In addition, the UniChip can also control boost pressure if an add-on module is fitted (£110.00) but facilities are limited compared to dedicated boost controllers such as the EVC-4 listed above. Fitting time for UniChip 2 hours. Mapping time (£70 per hour) can vary.
option 2:
F-Con S (fuel & ignition) piggyback ECU £890.00 . (All models) We are one of only 3 companies in Europe able to offer re-mapping of F-Con 5 units to individual specification. F-Con's are supplied with a plug-in factory quality wiring loom and thus do not need to be 'hard-wired' as with the UniChip above. Fitting time 2 hours. Mapping time (£70 per hour) can vary.
Stage 5 upgrade: (79 BHP) Front mounted intercooler kit 600x300x65mm £950.00 (picture below also shows HKS engine oil cooler fitted) Please contact us if you are thinking of carrying out this upgrade as you may need to also purchase other parts (such as PowerFlow air filter kit) depending on model year.
Stage 6 upgrade: (80 bhp +) HKS GT roller bearing turbocharger upgrade. £1,800.00
At last, a ready-made turbocharger upgrade for the Impreza from a reputable company! This upgrade does not use a so-called 'hybrid' unit which are always based on the original part. This kit uses the renouned HKS 'GT' turbine which uses a fully ball-raced shaft unlike some competitors which just use ballraces on the compressor side. The spool up time on these units is nothing short of awesome while reliability is superior to any other turbo we have seen. This kit has been fully tested at HKS's R&D facility in Japan and showed a figure of 362.5ps with 416.2Nm/42.5 kgf.m. It is important to note that these figures were achieved at a low 1.5 bar boost pressure. Even at 1.2 bar the same engine gave 333.5ps with 351.1Nm/35.8kgf.m! Obviously other parts were required for this set up i.e. Exhaust system, PowerFlow induction kit, front mounted intercooler, EVC boost controller, Front pipe, F-Con ECU and fuel pump upgrade.
An excellent saving for the minor hassle of getting a few 10p copper washers!
Stage 7 upgrade:
Full engine conversion £POA
OPTIONS
Suspension/handling:
HKS Hiper dampers (fully adjustable damping & ride height) and Super Dual Racing springs c/w adjustable rose-jointed alloy top mounts £1,850.00
Uprated and lowered HKS springs (all models) £285.00
Uprated and lowered Eibach springs (WRX) £145.00
HKS twin plate ceremetallic clutch and steel flywheel assembly £1,250.00
Various steel flywheels from £495.00
Transmission oil cooler kit £350.00
Quaife semi-helical cut gear kit. This kit is substantially stronger than the original gearset. Being semi-helical the tradtional 'straight-cut' gear whine is considerably reduced (although it is still louder than the OE setup). Ideal for hard road-driven Imprezas and track day cars alike! £1,975.00
Cosmetic:
Carbon fibre Sti spec rear spoiler £450.00
Fibreglass Sti spec. rear spoiler £395.00
Fibreglass WRX estate upper rear spoiler £495.00
Fibreglass WRX estate lower rear spoiler £595.00
22B adjustable rear spoiler £1,495.00
Dashboard 3-clock 60mm instrument pod £105.00
Clear front indicator set >98 (not 'e' marked) £79.90 pair As above but for 99MY on £85.90
Clear/smoked/blue/green side repeated sets £25.90 pair
Engine:
Turbo Timer and harness £95.00 STI Ver.1&2 silicone turbo pipes
(2) £37.35 STI Ver.1&2 silicone coolant pipes
(8) £168 .75 STI Ver.1&2 Silicone ancillary pipes
(8) £79.85 STI Ver. 3 Silicone turbo pipes
(3) £59.95 STI Ver. 4 Silicone turbo pipes
(4) £44.80 STI Ver. 4 Silicone coolant pipes
(8) £104.95 HKS iridium spark plug set £58.00
Various thickness uprated head gaskets from £325.00
J.E. Forged alloy piston set £800.00
Steel H section rods £950.00 Steel 'I' section rods £650.00
Engine oil cooler kit Ver. 4&5 £485.00
2.2 stroker kit using steel crank, steel rods and forged alloy pistons c/w rings and pins £3,000.00. Please note that the cylinder block will need liners fitted to accomodate this kit. We advise that we liner and/or re-build your short block ourselves due to the complexity of this procedure. Please call for pricing of this service.
Brembo 305mm dia. disc/4-pot caliper kit 16" £1,295.00
Brembo 320mm dia. disc/4-pot caliper kit 17" £1,365.00
Brembo 328mm dia. disc/4-pot caliper kit 17" £2,030.00
Brembo 332mm dia. disc/4-pot caliper kit 17" £2,380.00
We also have a comprehensive directory (220 pages) listing (and showing pictures of) all the parts available from Japan for this vehicle. We can supply these at a cost of £30.00 if required but please note that they are printed in Japanese!