It sounds strange, but geography often determines the type of mods you can expect from your local performance specialist. If you’re next door to where brand X management and intercooler systems are built then, generally, that’s what you get. Like it or lump it. But it’s true to say that many of the cars from Toowoomba, Queensland take their own route – and Mark Sepahlhut’s ’00 Subaru WRX proves it. While the basics of its mods are nothing new, the combination of parts is quite unlike what we’ve seen along the Eastern coast.
For a start, the engine has a whole bunch of bolt-on mods but the engine management remains stock. There isn’t even an interceptor. And, even more surprising, the engine retains its stock fuel system – bigger injectors and a replacement fuel pump simply aren’t required despite a dramatic breathing improvement.
Mark’s WRX runs a standard EJ20 which relies on aftermarket add-on bits an’ pieces for extra grunt. Of course, the restrictive stocker exhaust system has become landfill and in its place is a 3 inch mandrel bent system with a single muffler. The exhaust and all other mechanical mods can be credited to Auto-Tech Automotive and Performance. The air intake kicks off with a HKS pod filter mounted on the standard Subaru airflow meter (which is quite large in these late-model GC-series WRXs). The pipe between the airflow meter and turbo has recently been replaced with a polished stainless pipe after the rubber factory job deteriorated and started ‘sucking in’ under power.
The standard top-mount intercooler has joined the original exhaust in the afterlife and a PWR front-mount core with custom end-tanks now rides up front. There’s mandrel bent intercooler plumbing and Mark, a qualified painter, gave ‘em a lick of ‘stealth black’ paint. A compact Odyssey battery helps make space to route the ‘cooler pipes. On the return pipe to the engine you may notice a custom blow-off valve which is similar to an off-the-shelf TurboSmart product.
Standard WRX turbochargers are good for generating mid-range grunt but they’re not exactly comfortable pushing big power. Mark’s car has switched to a VF22 turbo – the big daddy of the STi range – which is mounted on a custom up-pipe with heat wrapping. As you might be aware, the VF22 is a bolt-on conversion to the standard up-pipe – the reason for the custom pipe is to accommodate a 35mm TurboSmart external wastegate. This eliminates the boost control problems sometimes associated with the VF22’s standard internal ‘gate. And, not only does it serve a purpose, Mark says it sounds great and looks cool when the bonnet goes up.
The only other go-fast mods are a TurboSmart e-Boost, GFB aluminium crank and power steering pump pulleys and a lightened flywheel. Mark recalls an aftermarket set of extractors were recently fitted but power and turbine response went backward. The stock manifolds were then refitted.
Mark is quick to point out the car is built as a quick street car – there’s no blurring the lines between drag car and circuit racer. As a result, he’s happy to retain the factory clutch which is prone to slipping on occasion but it’s a great way of maintaining the life of the gearbox and avoiding the problems of heavy-duty clutches.
Mark knows he’s got a quick streeter beneath him so he hasn’t been falling over himself to obtain a dyno power figure (not to mention there aren’t any AWD chassis dynos in Toowoomba). As a guide, a ’01 WRX with the same mods but no external wastegate has generated 320hp (239kW) at all fours so Mark is conservatively guessing he’s got around 300hp (224kW) ATW.
The lowered stance you see comes from an expensive adjustable coil-over upgrade. Tein street-spec adjustable coil-overs were delivered from Japan and, with the dampers set to the soft end of their range, ride quality is apparently pretty good. Mark says it’s definitely better than the previous configuration of aftermarket springs and strut inserts. A Whiteline anti-lift kit and alloy swaybar links further improve handling.
Brakes in the MY99/00 WRX are improved substantially over earlier mods with the move to 4-pot front callipers and ventilated rear discs. Mark’s Rex has switched to the popular DBA cross-drilled replacement discs along with a relatively soft set of pads to ensure maximum braking from cold and to minimise disc wear. Oh, and a coat of red paint has also been applied to the calipers – Mark says he did that before Subaru copied him.
Thankfully, Mark has exercised restraint when improving the look of the WRX. The early Impreza is a very rounded style car and it’s all too easy to bugger it up with aftermarket body kits with sharp edges and spoilers jutting out everywhere you look. Mark says he has no need for wings because, well, he’s not a pilot... Instead, he’s removed the factory high-rise spoiler and installed an all-new boot lid with no holes. A STi front lip, fog light covers, clear indicator lenses and full colour coding complete the body mods. Wheels are Avanti 18s painted black.
Currently, the car is modified as far as you can go without getting stuck into the fuel system, management and engine internals. But, rather than keep modifying what’s already there, Mark is currently considering dropping in a 2.5-litre STi engine along with its associated six-speed gearbox – late-model grunt in the lightweight early series Rex!
But it’s far from a definite decision.
A wise man once said “everything is for sale at the right price” and Mark is open to offers of around AUD$20,000 for his Rex as-is except you don’t get the WRX 04 number plates. Flick an email to email@example.com if you’re genuinely interested.
Auto-Tech Automotive and Performance +61 7 4632 1999