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Face of the Devil

The horns pop out every time the owner slides in behind the wheel of this 11-second devil beast!

By Michael Knowling

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If you've ever needed an example of how the Subaru Impreza WRX has changed the face of the performance car culture in Australia, here it is. Karl Jensen (aka Player) of Victoria used to kick around in a Mk1 GT500 Cortina, a Mk2 Golf, a Mazda 323 and a 2.2-litre Liberty GX; now he owns one of the quickest street drivers out there.

Here's a station wagon capable of running 11.5 second quarters on everyday pump fuel!

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Karl's move to the Rex was inspired by his mother's ownership of a then-new WRX in '95 (Karl's Mum, by the way, is now the President of the WRX club of Victoria). Not long after, Karl went out and splurged on a MY94 model wagon for himself. It was a complete stocker at that stage, mind you...

Despite thinking even the standard car was "the duck's guts" it wasn't too long before the mods started flowing. The restrictive factory exhaust was replaced with a 3-inch burbler, Karl installed his own Hobbs pressure switch activated intercooler water spray and whacked in a lowered set of springs. Boost pressure was also raised using a relatively uncommon technique; he simply shortened the wastegate actuator rod rather than install any kind of bleed, regulator or electronic boost control system.

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A little later down the track, a fuel pressure gauge was fitted and - just in time - it was discovered that the fuel system was maxing out. This dangerous situation was remedied with a Bosch Motorsport fuel pump and Malpassi rising rate regulator. Hmmm. Karl then realised he could now safely up the boost pressure further, so - with a wide-band air-fuel ratio meter up its tailpipe - he set out to find the highest possible boost pressure while still maintaining a fat mixture. The final boost figure - 21 psi - sure gave the car plenty of go but, unfortunately, disaster soon struck. An engine was instantly lunched when the boost pressure hose connecting to the top of the fuel pressure regulator popped off...


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Rather than drop in a replacement motor, Karl opted to piece together a stroker motor capable of making some big numbers. The assembly job was handed to Phil Lowe of SubieSports. After some discussion about the appropriate combo, the package that was screwed together includes PAR H-beam conrods and Aries forged pistons giving a higher-than-standard 8.5:1 static compression ratio. "There's no point building a low compression engine for the street, because you can't run big boost on pump fuel," explains Karl. And what of the stroker side of things? Well, Karl's not keen to give too much away except that his car runs an EJ25 (2.5-litre) crankshaft in a closed deck block "and there were a few tricks to installing it"... Take that as you will.

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The DOHC, 4-valve-per-cylinder heads also came in for a bit of a touch-up. Karl ported them himself and they were then reassembled using 1mm oversize exhaust valves and STi Version 3 camshafts. The standard hydraulic lifters used in early WRX engines are prone to 'pumping up' at high rpm, so Karl replaced them with a set of custom solid lifters (with accompanying mods to the heads). The block and head assembly was then tightened together using an aftermarket stud kit and 3-piece stainless steel Subaru head gaskets.

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And now onto what you can perve on after popping the bonnet.

Induction air begins its journey with an AVO/Simota pod air filter and a fat 4-inch silicone pipe into the turbo. Forcing up to 21 psi boost, a hybrid (internal wastegate) Garrett GT35/28 roller bearing turbo - said to be good for 500-550 horses - blows through BGT-fabricated piping into a beautiful A'PEXi GT-spec front-mount air-to-air intercooler. This has necessitated removing the factory driving lights - as you can probably tell from the pics. On-route into the engine, there's a PAC Performance blow-off valve, which Karl's surrounded in foam filter. Why? Coz this filter prevents any oil or vapours venting directly to atmosphere and, as a result, than means it is emission compliant. In fact, Karl tells us his entire vehicle is engineered and road legal.

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Part of this massive engine rework meant having to flick the standard engine management system, so rather than try splice in a 'universal fit' aftermarket computer, Karl went for a MicroTech plug-in. This allows the removal of the airflow meter (replacing it with a 3 Bar MAP sensor) and it currently works with the coil pack from a MY00 WRX, which has the necessary igniters built in. "You wouldn't bother trying to make this much power with the standard early WRX (direct-fire) coils - they're hopeless," tells Karl.

Dumping in the appropriate amount of fuel is a set of four 650cc Bosch injectors fed off custom fuel rails and drinking from an EFI Hardware surge tank. The aforementioned Bosch Motorsport pump remains in operation.

So how much power have all these mods netted? Well, a standard WRX is considered 'fast' with a mild 100-ish kilowatts at all four wheels - this one stomps out some 230kW at all fours on the Dyno Dynamics! Karl gets a kick out of pointing out that at only 4000 rpm it's making more power than an STi does at its peak!

And how does the WRX's troublesome driveline cope?

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Karl's gone through about eight clutches and five gearboxes, including a STi RA gearset (which broke) and a KAAZ aftermarket package (whose ratios were well off the mark). In the end, he's opted for a Race Brakes 4-puck solid centre clutch and 3500lb pressure plate, driving through a Modena dog box and Torsen front LSD (a near AUD$10,000 package!). And we've gotta say, despite some heavy use, this 'box is still humming (or is that whining?) quite nicely. In addition to the 'unbreakable' 'box, the standard front axles have been replaced by beefier Possum Bourne Motorsport items.

The driveline now seems to have pretty good longevity, but on-route to our photo shoot a couple of teeth were 'mysteriously' stripped off the front diff drive pinion (not part of the Modena upgrade). Ah, the joys of extreme mods!

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To prove Karl isn't just a straight-line drag kinda bloke, he's bolted in a set of ProSport (not related to those trendy shoes!) coil-overs, he's rose-jointed the front swaybar, added a front strut brace and adjustable strut top-mounts. These are set to deliver maximum possible castor. Brakes, too, are improved considerably. Gone are the stockie front anchors and 'in' are custom 320 x 32mm ventilated discs grabbed by big R32 Nissan Skyline GT-R calipers. Not surprisingly, this wasn't a quick afternoon swap - both custom aluminium hats and caliper mounts had to be fabricated. Oh, and braided lines ensure pedal pressure is converted to braking power with minimal losses along the way. In order to fit those monster brakes, a 'plus 2' wheel fitment was required, with a set of sparkling BSA 17 x 7s getting the nod. These are clad in Bridgestone Potenza 215/45s.

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Externally, the biggest giveaway to the number of horses Karl has herded under the bonnet is the standout front-mount intercooler. Still, Karl likes to try hide what's under there - the now redundant standard bonnet scoop has been removed and its aperture covered by a mesh insert Perspex. Other than that you'll notice those 17-inch boots, lowered stance, clear indicator lenses and a healthy dose of colour coding.

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Inside things are pretty cool - except, maybe, for those sheepie seat covers! Karl's installed A-pillar gauges for boost and oil pressure and console mounted gauges for air-fuel ratio and fuel pressure. Momo pedals, the MicroTech handset controller and harnesses are also part of this car's kit.

The beat of the tuned flat-four is more than capably drowned out by a pair of 12-inch subs driven off an Alpine V12 amp. Up front, the stereo system comprises an Alpine in-dash stacker and door splits - "I didn't want a remote stacker or any other speakers because I wanted to keep it reasonably light," says Karl. And, for the same reason, you'll find a little Odyssey dry cell battery hidden beneath the front passenger's seat.

Now let's cut to the chase - how fast is this thing?

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Well, with a madman like Karl at the helm this mighty Rex can wheelspin its way off the mark to a best G-Tech timed quarter mile of 11.5 seconds at 130 mph. Sure, it's not as quick as some other extreme Rexes, but go for a ride and numbers soon become academic - you can't ride in an 11-second WRX and not get excited. And - unlike many other hyper-fast WRXs - this sucker doesn't need to fill up with C16 race fuel to show its colours.

Don't let his eccentric character fool you - Karl's a calculating devil!


Thanks to Frank at Modena and Phil of SubieSports

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