There are heaps of modified Subaru WRXs getting around the traps these days. Everywhere you drive you'll hear that distinctive, muted flat four beat thumping away off somewhere amidst the traffic. But it seems, though, there's a few roughie "have a go" kinda enthusiasts out there that are getting their hands on these weapons. And that's a real worry in this day and age. To give you an example, we've recently seen a '94 Rexy equipped with an aftermarket fuel cut lifter and a completely disconnected wastegate actuator rod! No worries, mate, engine longevity isn't going to be a problem...
On the other hand, Mark Bourne (perhaps a long-lost relative of the great Possum Bourne?!) isn't like that. His WRX is one of the most all-round intelligent WRXs we've ever seen - and it shows at the track. How 'bout consistent 12.1s at around 113 mph? And when we say consistent, this poor car has pulled off well over sixty full-blooded passes - torture in the extreme!
Mark picked up this blue WRX brand-spankers new in 1998 (which was a huge jump coming from a predominantly V8 background). Since then, it's mostly been the focus of both himself and local Gold Coast company, ChipTorque.
As per usual, the mechanical modifications game started with a 3-inch mandrel exhaust (the work of Custom Exhaust Specialists), which uses a removable hi-flow cat converter and a straight-through rear muffler box. The High Performance Coatings front section of the system is interesting too. It uses a separate pipe from the wastegate, which then merges into the main 3-inch pipe about a metre downstream of the turbine. The theoretical aim of this is to minimise post-turbo turbulence and to carry exhaust gasses away as quickly as possible.
After this mandatory 3-inch system fitment, the out-of-the-ordinary mods hit like a tidal wave.
In one of the very first, a visit to ChipTorque saw the chip re-written, which - most importantly - allowed boost to reach a new maximum of 18 psi. A little later, the standard (and heavily stressed at 18 psi) WRX turbocharger was removed and in its place went a bolt-on STi VF23 unit (which has also been high-flowed by ProSpool in Brisbane). The entire range of VF series turbos has helped many-a WRX along to a spectacular quarter mile time.
We especially like the intercooler set-up on Mark's car. Instead of ditching the standard intercooler in favour of an expensive aftermarket front-mount device, Mark decided to improve on what he already had. After a bit of flowbench testing, the stand Y-pipe (that forms the twin-entry part of the intercooler) was seen as a major cause of restriction. The answer - since Mark works at aluminium boat manufacturer Quintrex - was to make a bigger diameter custom alloy feed pipe. Fitted up, this simple mod gave the intercooler enough flow to shade the genuine STi product by a whole 30 cfm! Score: Mark - 1; STi - 0.
With improved intercooler flow, enhanced cooling was next on the agenda. Mark's installed his own water spray system, which gets triggered at 9 psi by a simple Hobbs pressure switch. Together with the HPC'd dump pipe off the turbo, heat soak into the core shouldn't be such a huge concern anymore either. However, the exact results of these changes are seen on a dual mode temperature display, which is mounted on the steering column. The verdict - they've worked! Another turbo system item that received attention was the factory blow-off valve - which leaks like the convertible roof of a Ford Capri. So to prevent pressurised induction air escaping (when it isn't supposed to), an AVO valve was fitted instead.
Under the bonnet of this WRX looks remarkably standard for a 12.1 second car. Not only are the intercooler and turbo mods barely noticeable, the intake to the turbo has also been improved stealth style. By fitting a K&N insert and running a custom 4-inch duct from the airbox to the right hand grille in the bumper, there's been an immediate noticeable increase in torque and response.
Another "sneaky" fabrication during Mark's work hours was the aluminium oil/air separator, which stops oil coating the inside surfaces of the intercooler.
Now we recommend that you read the next paragraph very slowly - it's a bit of a tough one to swallow... Despite having powered down the quarter mile more than sixty times, and copping 40,000 kilometres of enthusiastic driving on the street, the gearbox of this WRX is 100% standard and in fact is yet to come out! And the fact that there's no clutch slip (thanks to a Jim Berry 2500lb pressure plate clamping the standard clutch) won't be helping things either! Then of course, there's also Mark's outlandish drag strip launching technique. He simply just dumps it at high revs and the car lunges about a metre sideways! His 1.6 second 60-foot time proves just how well it gets off the line...
Another appealing aspect of this car is it doesn't look too OTT. It's just immaculately clean and smooth. Draped in the factory metallic blue paint (which Mark says turns red-ish/blue in certain light), the body is standard - with the exception of some STi enhancement accessories. At the front is a genuine STi Version 4 front bumper extension (which was converted from three pieces into one), STi foglight blanking plates and a pink grille emblem. Other than that, the windows have also been treated to a light tint, and did you notice the RNS 12 rego plates? Clever eh?
All of this sits around 40mm lower to the ground due to the re-set factory coil springs (which are working with the stock inserts), while handling is further improved by a STi carbon fibre strut brace. Those red-hot wheels really catch your eye don't they? These are one-off six spoke polished eighteens, and are presented wearing expensive Pirelli P Zero 225/35 tyres. Peer in between their highly polished spokes and you'll see a DBA drilled and slotted disc brake staring back. These work well with the otherwise standard ABS anchors.
The late model WRXs are all pretty trick inside - that's why not much has been done in this area of Mark's car. The factory Nardi wheel, leather knob, rally-type seats and white-faced dials make an exceptional off-the-shelf package. However, Mark has upgraded to Momo pedals and installed a Blitz boost and exhaust gas temp gauge (which often reads up to around 600 degrees C) in A-pillar pods.
After our photo shoot, we were lucky enough to go for a quick hoot with Mark. And, yes readers, you sure get the seat-of-the-pants feeling that this is a real 12-second car. It's f-a-s-t. But it never delivers a rush of torque that tries to send the chassis into a wobbly - it's all beautifully progressive. 120, 130 - the speedo needle just keeps swings around at a terrific rate. And at the end of our fast burst, a smiling Mark summarises it all in a few brief words - "yeah, I'd never go back to a V8"...
Contact:
ChipTorque
+61 7 5596 4204
ProSpool
+61 7 3349 9511
Jim's Clutch
+61 7 3891 6114
(Australian Competition Clutch Supplies)
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