Plan of Attack

At the risk of sounding like a cola commercial, it's the first of a new generation. It's one of AutoSpeed's first fiddled new-shape WRXs and it won't be our last! This MY02 - or Series VII, depending on your accent - Subaru WRX is chock-a-block with aftermarket gear to make it go, stop and handle with far more authority than the factory stocker. Sure, it's not going to win any World Rally Championship rounds, or take home the trophy as the fastest street-registered drag car on the planet but look beyond the sign writing (see sidebar) and this bright yellow zonker is a rolling demonstration vehicle for what an enthusiastic owner can buy and bolt on when the time - and finance - comes to start playing with a S7 WRX.

This car was build co-ordinated by Brett Middleton of MRT Performance. Brett's the talking head of the family-run MRT (Middleton Rally Team), a high-performance specialist based in Sydney. Brett began rallying Datsun 1600s (the '60s 510 series cars) years ago and has tinkered with and successfully rallied several other marques, most notably Daihatsu and Honda, in Australia and overseas. In the past five years, MRT's attention has focussed on the WRX - both in the bush and in the workshop.

The VII's engine is an evolution of the EJ20 engine that has laid throbbing between the front legs of the WRX ever since its launch in 1994. Thanks to Subaru's flat-four engine architecture, an enduring feature of the WRX has been the top-mount intercooler that sits above and just behind the engine. The original design intercooler was praised for its logical location - its layout leading to shorter intake plumbing for better throttle response - and relatively large size compared to many other turbo cars of the era, however, there's always room for improvement. The MRT Performance unit fitted to this car is definitely an improvement, having a fatter and wider core for greater heat-shedding ability. The intercooler's end tanks are hand built from sheet alloy and with a bar and plate core, according to MRT it's ideal for supporting a modest increase in boost and power on an internally-standard WRX without the compromises of plumbing a full front-mount intercooler into the car. Which, of course, MRT Performance is also happy to do to any WRX that warrants it.

An MRT Performance TMS3 closed-loop boost control kit, as well as doing what you'd expect, sprays water over the bigger intercooler. MRT has a range of boost control boxes that also offer a wide range of additional functions such as turbo timing and controlling water spray onto the intercooler. As anybody who has ever stepped out of a swimming pool on a windy day will vouch, evaporating water sucks the heat out of your skin. In the case of an intercooler, the evaporating water from the spray soaks the heat from the fins of the alloy intercooler and ultimately the turbo-heated intake air within it. The TMS3 is MRT's top-lin boost controller and can be configured to spray water according to a variety of user-chooser conditions with thermo couple /boost and water temp inputs as well as featuring a turbo timer function to prevent cooked bearings, boost readout - including peak boost recall memory - and a rich/lean exhaust mixture indicator.

The intake system of the car gulps plenty of air through a Unifilter foam pod filter that sits where the original air box used to be. Now, some of us might be cool (!) on the idea of a pod filter breathing hot air from within the engine bay, but MRT doesn't see this as a problem. It's a much better situation than the engine having to draw air through its factory-fitted snail shell of induction resonance-tuned intake plastic pipe tucked into the offside wheelhouse. Besides, it's blown upon by the standard cold-air intake duct that channels cold air from below the bonnet lip and drains it, like a water works fun slide, for the Unifilter to inhale.

Adding to the driving experience is a set of GFB (Go Fast Bits) engine drive pulleys. Larger diameter pulleys slow the speed of engine accessories (such as the alternator) down, reducing parasitic drag on the engine. In the same way a small, fast-spooling turbo gets up to speed quicker, lower pulley speeds leads to snappier throttle response, something you can really feel, according to MRT. Makes sense to us.. A GFB Hybrid blow-off valve is also fitted.

So, Brett, how much power does all that good gear add up to? "I'd rather not quote power figures, actually," Brett diplomatically replied. "But the comment back from the company that owns this car was that they were amazed at the difference in performance and handling of the car after it was enhanced. And that's the truth. I know what the power is, but I don't quote power figures. Everybody just shops around for a power figure these days. Every car always varies. Let's just say that MRT gives a money-back guarantee on performance and we haven't needed to give too much back over the years!"

Still to come is an engine management system tweak that will enable MRT to further refine the car's tune. Available for all first-generation model WRXs, the tweaker is known as Ecutek and is undergoing final prototype testing for the S7 version. It will be on the streets by late 2002.