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Subaru WRX 2.5 RS - Wicked Radical Xtreme

A Balanced Attack Pegs This Subaru's Mojo Meter

Sep 10, 2002
Turp_0209_01_z+subaru_impreza_wrx+front_view Photo 1/1   |   Subaru WRX 2.5 RS - Wicked Radical Xtreme

376 WHP @ 18 psi
It's no secret the Subaru WRX would be a hit the second news of its pending arrival on American shores was announced. Heck, we have been clamoring for the, "real deal" for years. And we must say the 2.5RS, the ultimate teaser-rally-bred styling and all-wheel drive, but no turbo under the hood-really hurt.

But it's all good now. We have the Mojo of motordom: turbo power. The WRX dishes out 227 hp at the flywheel and does so through no less than four catalytic converters. Any car with a turbo has a distinct advantage in potential over naturally aspirated and supercharged variants. Savvy enthusiasts know this and have exploited the advantages the WRX brings to the table. Few have exploited better than Earl Mangune, who bought the Scoobie featured here despite working at, of all places, TRD. Not one to let his ride sit idly in stock trim, Earl transformed his WRX into a power monger of the Nth degree.

While this car was part of our "Subaru Invasion" section in the January 2002 issue, it evolved significantly in the power department, styling, suspension, interior-you name it.

An AVO Turboworld turbo upgrade package provides the real mojo. At the heart is a Garrett hybrid ball-bearing turbo. On the intake side of the system are an AVO blow-off valve and air intake kit, high-velocity intake pipe and a trick front-mount intercooler. On the hot side, a set of HKS stainless-steel headers direct exhaust gases to a common collector, then to a Paisley Racing up-pipe and on into the turbine housing. From there, an AVO stainless-steel downpipe evacuates gases via an AVO 3-inch stainless-steel exhaust system.

Odds and ends consist of a Paisley Racing radiator, Zero Sports radiator shroud, GReddy aluminum catch can and an HKS Earth Circle System, which provides ample grounding for heavy-duty electrical needs.

Tuning is attained via a Link Engine Management ECU, which is a Link circuit board swapped in place of the OE motherboard within the factory ECU. The Link board is pre-tuned for added zest and is accessible via laptop for fine-tuning. With the stock injectors and stock fuel pump, the flat four pulled 308 whp on Brainstorm's Dynamic Test Systems four-wheel-drive dyno. An HKS EVC IV controller regulates boost to 8 psi and the Subaru feeds on 91-octane pump gas.

With the stock fuel system maxed out, a set of Blitz 525cc injectors and a Blitz high-flow fuel pump were added. The WRX was taken back to Brainstorm for additional power extraction therapy. Fuel is bliss and the 2.0-liter responded in a big way, spiking the Turbo Mojo Meter by generating 375.9 whp and 296.6 lbs-ft of torque.

Its all-wheel-drive system's agility is an inherent strongpoint for the WRX. Earl expanded this envelope with a myriad of components that work in unison to resist body roll, absorb bumps and carve apexes. The core of the suspension is a set of Tanabe Sustec Pro coil-overs that allow a wide degree of lowering to be dialed in to the Subaru.

The frame structure has been fortified against flex via Cusco front and rear strut tower bars and a Cusco rear triangle bar. The triangle bar mounts in the trunk just behind the rear seat and braces that section off the body by tying together the trunk hinges and floor. To ensure grip at extreme g-loads, Cusco camber adjustment plates allow quick changes for running hard at the track or cruising around town.

Braking is a key element of any car with canyon-carving aspirations. Earl's WRX can aspire to hang with the best of them, thanks to a hard-hitting upgrade from Wilwood. The Subaru runs wild six-piston front calipers with gargantuan 13-inch drilled and slotted rotors. The rear is also fitted with a Wilwood upgrade consisting of four-piston calipers and 12.9-inch rotors-an upgrade larger than most. The Wilwood kit comes with stainless-steel brake lines to ensure a firm pedal. When the caliper grabs the rotor, it's the tire that must be up to the challenge. To fit the brakes, Earl bolted on a set of lightweight 18x8.5 SSR Type-C wheels shod with Toyo Proxes T1-S tires of the 235/40ZR-18 variety.

Since we last saw it, the Subaru's sheetmetal has been massaged in a distinctively JDM manner with a gaggle of parts from STi (Subaru Tecnica International), the company's rally racing division. Earl's STi parts consist of fog lamp covers, front corner lights, trick headlights, pink grille logo, a front lip spoiler and rear side panels. A really cool carbon-fiber hood from Carisma rounds out the body mods.

The Subaru's leading edge is protected by Star Shield's paint protection film, which covers the paint on the bumper and spoiler and protects the finish from flying rocks and other debris. This film seems like a most promising product and we hope to test it ourselves in a future issue.

The party keeps on pumping in the cabin where a well-placed grouping of HKS meters keep Earl updated on vital engine operating parameters. A boost gauge is mounted on the gauge cluster visor and oil pressure, EGT and voltage readouts are contained in the upper center dash pod that originally housed a clock. Sparco Torino racing seats were installed with custom bracketry fabricated by Design Craft. Extra seat material was used by Stitchcraft to tie in the door panels and rear seats. Daily commutes are softened considerably by an Eclipse/Boston Acoustics audio system. The crazy system, installed by TM Engineering, is detailed in an accompanying side bar.

The Subaru impresses because every system of the vehicle, from sheetmetal to underpinnings and beyond has been addressed with a high degree of detail. Best of all, this car is driven every day and using the power, not just having the power, is what Mojo is all about.

High-Performance Stereo
Big Watts, Little WeightEarl's WRX runs an Eclipse head unit, but his concerns centered around vehicle performance-translation; weight. Luckily, Boston Acoustics was thinking on the same wavelength.

As a result, the front speaker tandem in Earl's Subaru consists of Boston Acoustics NX67s. NX stands for "neodymium coaxial." These speakers use neodymium magnets for both woofer and tweeter. This magnetic material was chosen for two reasons.

First, you get high energy from a compact motor structure, a neodymium motor replaces a much larger, conventional magnetic motor. This allows the NX speakers to fit more easily into new vehicles because the motor is more compact. As manufacturers try to increase interior space of a vehicle while keeping the overall size of the vehicle the same, interior partitions such as door panels move outward which reduces the rear depth. This can create great difficulty when you are trying to install a conventional speaker.

The second reason is low weight. NX neodymium magnets have a fraction of the mass that a conventional magnet has. This is important from a vehicle dynamics standpoint. If a customer has gone to the effort to purchase a high-performance car, why would he want to affect the handling or braking of it by loading it down? Most would not and that is why NX is a great dovetail for that customer. You can get true high-performance audio without the associated weight penalty.

Pumping out the bass falls to a Boston Acoustic Generator GS1002 10-inch subwoofer. The Generator GS1002 subwoofer can work in a small sealed or vented box. It uses Boston's Direct Vent voice coil cooling and has multi-layer windings for better power handling. Both the sound quality and SPL are on par with a more expensive woofer. This one is supplied with a 2-ohm impedance to extract maximum power from the GT-40 amplifier.

Powering the combination is a Boston GT-40 amplifier; the most compact 4-channel that Boston offers. In 3-channel mode, the amplifier is rated for 2x55W & 1x230W @14.4VDC. It will be used in this configuration in Earl's car. The amplifier is stable into a 2 ohm mono or 1 ohm stereo which means multiple speakers can be used without causing the amplifier difficulty. Great attention has been paid to heat management and cooling. The GT-40 uses a high-efficiency heatsink with extra thermal mass to provide excellent passive cooling. Should the passive capacity be exceeded, fans kick on to lower the operating temperature. This lets the amplifier work in the most extreme conditions.

System Weight
(2) Boston NX67 Neodymyium coaXials
+ (1) Boston GS1002 Generator Subwoofer
+ (1) Boston GT-40 4-channel amplifier
= 15 Pounds
Keep in mind that an enclosure must be built for the subwoofer.


Prescott, 86301
GReddy Performance Products
Irvine, CA 92618
Toda Racing
Irvine, CA 92618
Toyo Tires
Boston Acoustics
Peabody, MA 01960
Azusa, CA 91702
Irvine Subaru
Lake Forest, CA 92630
Wilwood Disc Brakes
Camarillo, CA 93012
Paisley Racing
Hempstead, NY 11550
Tanabe Suspension/Mackin Industries
Santa Fe Springs, CA 90670



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