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.
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.
(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.