We know what you're thinking. "Here's yet another over-the-top WRX with a stroker kit, a massive turbo and 10-second quarter mile performance." Well, you're right and wrong. For sure - with a plump $90,000 of mods - this WRX does carry a stroker crank; but it's not built to run impressive times at the expense of driveability and practical use. This is an all-round road scorcher with race-grade brakes, suspension and top-line everything.
This is the top WRX in the country.
Matt, the owner of this surprisingly stock looking MY99 WRX, started off making increased power with an exhaust, intercooler, intake and engine management mods. As you'd imagine, the little Rex went pretty well - until it stopped going all together. Brett Middleton of Sydney's MRT Performance tells us it had "torched the number two piston".
Once this engine damage had occurred, Matt had the car shipped to MRT from interstate for a "significant" upgrade and rebuild. Unlike many WRX build-ups, this was not to be a peak power chaser; rather, it had to have a tremendous torque spread with strong throttle response. This is, after all, a car that drives along door handle-to-door handle with other cars in thick traffic.
With useable torque on everyone's minds, MRT utilised their in-house 2.18-litre stroker kit. This included a stroker crankshaft, H-beam rods with heavy-duty bolts (which are claimed lighter and stronger than OE) and Teflon-coated forged pistons (giving a custom 8.5:1 compression ratio in this case). Standard turbo-spec rings and bearings were retained. Note that the MRT stroker crank is particularly well suited to the width of the standard turbo-spec bearings, and the slightly higher-than-standard static CR ensures strong off-boost performance. With the standard block heavily damaged from the aforementioned meltdown, a genuine STi block formed the basis for a problem-free build. This is a closed deck design for greater stiffness and head gasket durability.
To each side of the STi block were bolted the standard (solid lifter) heads equipped with Version 5 STi camshafts. These offer different lift and duration to standard, but Brett suggests that the biggest difference comes from the added duration. Brett also tells us the block needn't be O-ringed thanks to their own safe-sealing steel head gaskets. GFB (Go Fast Bits) aluminium under-drive pullies were fitted to improve throttle response and give the potential to release slightly more power.
With the motor assembled, it was then time to select the turbocharger - something that can make or break a good street package. Interestingly, MRT opted for a VF22 unit (the largest of the commonly used VF-series) and mounted it on their own pre-turbo extractor manifold. Brett reveals that the standard pre-turbo pipes have a restrictive 3mm lip inside the castings that bolt to the heads. Furthermore, the lower sections of the MRT extractor pipes were heat-wrapped to keep a few degrees away from the nearby oil filter and coolant plumbing.
Downstream of the turbocharger is one of MRT's updated 'splitter' dump pipes, which maintains separate turbine and wastage passages for about 30cm. This set-up is said to reduce lag. Once gently merged, the pipes run into a full MRT 3-inch system with a flex joint, high-flow cat, centre and rear mufflers. A 4-inch tip emits the EJ motor's distinctive song.
Commencing airflow into the turbocharger is a MRT Group A Unifilter kit, which leads into a 80mm silicone inlet pipe (running beneath the standard 'hi-rise' intake manifold). Boosted up to 25 psi, intake air then rushes through MRT stainless steel intercooler piping into one of their in-house front-mount bar-and-plate air-to-air intercoolers. This is augmented by a MRT water spray, which sees a 25-litre aluminium in-boot reservoir, a Flojet pump and STi nozzles. The system is activated via the programmable ECU, depending on inlet air temp and boost pressure. A GFB blow-off valve is tee'd into the plumbing leading to the engine.
And now we introduce you to what is arguably the best aftermarket injection set-up in the world. A top-shelf MoTeC M8 ECU controls this Subaru's fuel, ignition and boost. Note that a restriction-free MAP sensor replaces the factory airflow meter. Fuel (which is always Shell Optimax) is pushed into the chambers thanks to four Bosch 363 injectors, which are fed off custom fuel rails. Pressure is maintained by dual regulators - an arrangement that is said to reduce the chance of lean-out. These work in conjunction with a '600hp' Bosch Motorsport pump, in-boot surge tank and the standard in-tank lift pump. Sparking the combustion process are the standard Subaru coils, cold NGK platinum-tip plugs and 10mm Formula leads, though Brett says a M&W booster may soon find its way into the picture. WRXs, he says, are sometimes prone to fouling plugs if they aren't put under high load often enough (like anybody needed an excuse to go for a full-boost burn!).
Backing the EJ engine is a MRT lightweight billet chrome-moly flywheel and a MRT heavy-duty pressure plate and nine-segment, full-backed ceramic clutch plate. Brett says a 'proper' paddle clutch was too savage, given the car's frequent traffic encounters. Bearing the brunt of the transmitted torque is an STi Group N gearset with MRT synchros, with a 20kg/m centre viscous apportioning drive front-to-rear. As discussed in a previous AutoSpeed feature ["Viscous Coupling Variations"] the 20kg/m centre coupling serves to maintain near-equal driveline speed from front to rear. Mechanical limited slip diffs are fitted at both ends of the car; in short, traction is not a problem.
And here comes some more top-notch gear...
The standard WRX front axles have been discarded in favour of fatter shafts boasting heavier-duty CV joints. These were built up using a carefully selected pair of Subaru shafts (not from the Liberty RS). Heading outward, we come to the front brakes - and these are true monsters! How do six-pot AP calipers grab you?! They sure grab the 335mm drilled AP discs pretty well; Brett says he's still blown away by the brakes every time he takes the vehicle for a run.
The rear brakes are equally improved over standard. Here we see 295mm 22B ventilated discs squeezed by 22B 2-pot calipers. Pagid blue pads are fitted in each caliper body and braided lines are used throughout. Like the fronts, the rear muthas hide behind 18 x 8 BBS rims, encrusted in 225/35 Potenza S-02s.
As you might be aware, fitting such huge rims and rubber under the back of a WRX is a tall order. In addition to having the guards lipped and pumped, MRT had to adjust the track and camber. This called for lengthened rear axles and MRT adjustable lower control arms. Even still, there's only j-u-s-t enough tyre clearance.
The suspension itself is competition-inspired yet easily liveable on the street. DMS (Drummond Motor Sport) 50mm Giant struts give the WRX adjustable ride height, camber, bump and rebound. Further improved handling comes from adjustable Whiteline front and rear swaybars, an anti-lift kit, STi carbon fibre front strut bar and a Whiteline rear strut bar. Nolathane and STi bushes are installed throughout and a STi heavy-duty roller-bearing front strut top allows for generous castor.
Inside the cabin are more mega-buck (and ultra-desirable) goodies. Complimenting the MoTeC M8 computer is the MoTeC dash display, which - in this case - is mounted inside a MRT carbon fibre pod. The LCD screen shows lambda, inlet air temperature, manifold pressure, engine rpm, oil temperature, oil pressure, coolant temperature, fuel pressure, gear position and trans fluid temperature (thanks to the fitment of a sensor in the side of the gearbox). A column-mounted 2-stage shift light is also wired to the MoTeC dash.
But wait, there's more! The factory rally-style seats have been trimmed in quality leather (front and rear), a Momo racing harness wraps around the driver's pew and a flip-out Alpine video/CD stacker with CARiN navigation all live in the dash console. A fire extinguisher can be used to protect the otherwise standard interior.
Somewhat surprisingly, this killer WRX is barely modified on the outside. The factory side-skirts, mirrors and door handles have been colour-coded in factory metallic blue, the windows have been tinted and the boot lid now carries a hard-to-miss 22B adjustable rear wing. We doubt whether the roof racks have an aerodynamic cross-section that aids downforce, however...
By now, you'd get the picture that this WRX is like no other - spending 90k in mods will do that! Chances are, though - like us - you're wondering how much power it makes and what ETs it can cut over the quarter mile. Well, we couldn't get an answer out of Brett; he explains that this is not a peak-hp machine and he didn't want anybody drawing comparisons. Instead, he told us that it made double the factory torque output at 4000 rpm.
Just between us, we'd guess that a car with this list of mods should be capable of running high-11s/low-12s over the quarter. In traffic, though, it'd leave lower-ET WRXs watching the 22B rear wing disappear before they climb onto boost. Throw a few tough corners into the equation and this Rex would pull away even further!
Now you know why this is the best WRX in Australia.
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Since photographed, the car has received Mines carbon fibre electric mirrors, an alloy under-body chassis brace, a rear diff brace and a Whiteline rear suspension lock kit. Will it ever end?!
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Contact:
MRT Performance
+61 2 9809 2110
info@mrtrally.com.au
www.MRTrally.com.au
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