MY2002 - European-Specification Impreza WRX STi

STi to Europe

The official import of the WRX STi was made after much speculation and rumour with a press release made at the Frankfurt Motorshow in September 2001. The following Subaru UK press release was made on the final day of the British round of the World Rally Championship on the 25th November 2001.

TYPE-UK IMPREZA WRX STI ARRIVES

January launch for 265 PS Impreza WRX STi
Two versions - one with Prodrive-designed upgrade
Priced from £25,995 on-the-road
Full European Type Approval
148 mph top speed and 5.2 seconds 0-60 mph time
Meets all European noise and emission regulations
Heavily modified turbo engine with Active Valve Control
New six-speed gearbox
Larger Brembo brakes
Larger 225/45 tyres on gold spoked 17x7.5 alloy wheels
Uprated suspension with inverted struts
Front and rear 'Suretrac' limited-slip differentials
Faster steering rack for sharper responses
Styling highlights include smoked glass projector beam headlamps
Standard satellite anti-theft tracking system
Subaru's ultimate Impreza WRX - the STi - enters UK dealer showrooms in January 2002 priced from just £25,995 on-the-road.

The 265 PS, six-speed road-rocket was first unveiled in European-spec at the Frankfurt Motor Show in September 2001.

Two versions are offered for the United Kingdom - the 'standard' STI and the special edition STi Prodrive Style with Prodrive-designed spoilers, grille and front bumper.

Both will be designated and badged 'Type-UK' to distinguish them from 'grey' imports which do not have European Type Approval, and to reflect the additional features standard on the British versions.

These include a Category One alarm/immobiliser, a special satellite tracking system, enhanced rust proofing to cope with the harsh UK weather, locking wheel nuts and a three year/60,000 mile warranty plus three year membership of Subaru Assistance.

Instantly recognisable as WRX range-toppers, both models have smoked glass projector beam headlamps, bigger bonnet air intakes and a single large-diameter rear exhaust pipe.

Other shared differences to the regular WRX include special gold-coloured spoked alloy wheels, colour-keyed sill spoilers and an interior featuring blue suede-effect seats with STi logos and red stitching for the steering wheel, gear **** and handbrake lever.

Also inside - and sure to please enthusiasts - is a switch to spray the intercooler with water. Another device allows the driver to preset a warning buzzer and light to guard against over-revving the engine.

On opening the bonnet, the engine compartment greets owners with a dramatic mixture of colours and detailing. The intake manifold, for example, is painted in red and the enlarged aluminium intercooler emblazoned with 'STi' lettering.

In addition, the STi Prodrive Style features a massive high-riding boot spoiler, newly designed sill spoilers and a deeper, squarer front bumper. The grille and badging resemble the WRC rally car. Interior enhancements over the standard STI include dark blue-coloured instruments with red needles. The Prodrive Style costs £27,495 on-the-road.

The Impreza STi and STi Prodrive Style will be available in four colours: WR Blue Mica, Blue Black Mica, Premium Silver Metallic and Pure White, the latter two being special order only.

The STI has a top speed of 148 mph and 0-60 mph time of 5.2 seconds from an engine which has been specially developed to meet European Community Whole Vehicle Type Approval standards - unlike the Japanese home-market STi.

Engine In Detail

Tuned by Subaru Tecnica International Inc
Larger air to air intercooler with water spray
Sodium-filled exhaust valves
Hollow intake valves
Reinforced engine block and connecting rods
Forged pistons
Shimless valve lifters
Active Valve Control System (variable valve timing)
265PS and 253lbft of torque
Up to 80 per cent of the STi's all-alloy engine is new compared to the standard turbocharged 2.0 litre four-cam 'boxer' unit as fitted to the regular Impreza WRX.

Extensive and painstaking modifications by Subaru's motor sport division - Subaru Tecnica International Inc - combine the utmost durability, performance and throttle response with the fuel economy, noise and emission levels expected of a road car.

In order to meet the stringent Euro3 exhaust emission levels, the catalyst is uprated, the air-fuel ratio sensor modified and special multi-hole fuel-injectors fitted. Engine strength and rigidity are boosted by using semi-closed-deck cylinder blocks, reshaping the piston head, fitting screw-in type connecting rods and using forged pistons and shimless valve lifters. Also aimed at high-rev durability are sodium-filled exhaust valves and hollow intake valves.

A larger intercooler and air intake provide better cooling and a special intercooler water spray is fitted, operated by the driver with the water tank fitted in the boot.

Also specially fitted to the STI is Subaru's Active Valve Control System - variable valve timing - which ensures maximum engine response over a wide rev-range.

The result is a maximum power output of 265PS (261.5 bhp/195 kW) at an accessible 6,000 rpm and 253lbft (343 Nm) torque at an equally usable 4,000 rpm.

This compares with the standard WRX figures of 218PS at 5,600 rpm and 215.4lbft of torque at 3,600 rpm - significant increases of 47PS and 37.6lbft.

As with the normal WRX, the horizontally-opposed four-cam, 16-valve 'boxer' engine has a bore and stroke of 92x75 mm for a capacity of 1,994 cc and runs on an 8.0:1 compression ratio.

While not a top priority for performance car owners, fuel economy is a respectable 29.7 mpg on the Extra Urban cycle.

Transmission In Full Described by some as one of the slickest-shifting manual gearboxes currently available, the European version of the STi features the same completely new six speed transmission as the Japanese model.

This short-throw close-ratio 'box' has been designed to withstand high torque outputs and features extra rigidity thanks to expanding the distance of the main gear shaft by 10 mm and increasing the face width of the gears.

Instead of turning the STi's sixth gear into an economy-orientated overdrive, Subaru's engineers have chosen low gearing for lively acceleration.

For example, the STi's fourth gear virtually matches third on the WRX, while sixth pulls 24.5 mph/1000 rpm versus the WRX's 24.7/1000 rpm.

The clutch is uprated and larger, with increased loading on the clutch cover. Meanwhile, both lubrication and cooling are improved through the use of an oil pump in the main case. Engagement of reverse gear now requires the lifting of a pull-up slider ring.

Steering, Suspension And All-Wheel Drive System In Full

Subaru's leech-like grip, superb balance through corners and interactive handling thanks to its sophisticated all-wheel drive system are further enhanced on the STi.

However, in wet, muddy or icy conditions, the viscous coupling senses which axle has the better grip and distributes torque accordingly to minimise the risk of wheel spin.

This is further enhanced by a limited-slip differential in the rear axle, sharing available grip between each rear wheel.

Now, for the STi, Subaru has taken its AWD system one step further by installing a 'Suretrac' LSD in both front and rear axles. 'Suretrac' is a registered trademark of Automotive Products UK.

A slightly faster steering rack gives sharper responses and reduces the number of turns lock-to-lock to 2.6. Also for a firmer feel, the suspension bushes and front and rear suspension arms are uprated.

Of even more significance is the revision to all four suspension struts which are now inverted - just like the WRC rally car. This gives superior geometry control and damping performance during hard driving.

Wheels, Tyres And Brakes In Full

In order to fully exploit the extra power and improved suspension, the STi's wheels and tyres are slightly larger than the standard WRX.

For example, the specially designed multi-spoke gold alloy wheels measure 17x7.5ins instead of 17x7ins and the tyres grow from 215/45 to 225/45. This typifies the subtle fine-tuning lavished on the entire car by Subaru and STi engineers.

Fast cars need good brakes and the STi features an ABS braking system made by renowned specialists, Brembo S.p.A of Italy.

Key features include larger ventilated front and rear brakes with four-pot aluminium callipers at the front and twin-pot offset opposed aluminium callipers at the rear.

Actual front/rear brake size grows from the 11.5ins (292mm)/l1.3ins (288mm) of the standard WRX to 13ins (330mm)/12ins (305mm) for the STi.

The enhanced ABS system also benefits from a lateral G sensor and EBD (Electronic Brake Distribution). This ensures maximum braking control.