When we first heard the crew over at XS Engineering had acquired a Subaru WRX, we knew the wrenches would be turning at warp speed. In the time most are still getting used to the new-car smell of their Subaru, XS Engineering had already reengineered the WRX to be prime-time performer. In the short six months after the Subaru's release, XS Engineering had already built a fully tweaked WRX with all the amenities of a pro rally street car.
One of the first areas XS worked its magic was the exhaust system. To help promote spool up of the turbocharger, the XS crew developed a free-flowing exhaust system. The exhaust features 3-inch, mandrel-bent piping and an A'PEXi N1-style polished stainless-steel canister. Offered in three different sections, a front downpipe, mid section and rear exhaust allows for enthusiasts to choose a street-legal system or a full race set-up.
On the induction end of the turbocharger, XS massaged the intake tract by building a cold-air intake system. Knowing systems that draw air from the hot engine compartment may not be realizing their maximum potential, XS crafted a cold-air system. Drawing cooler charge air from the fender well or bumper compartment translates into more oxygen by volume in the charge air--and more power potential.
Dyno testing by the company has resulted in 10 to 15 hp increases by the intake alone. It is obvious that heat rises and in the case of the Subaru, installing the intercooler on top of a very hot engine was probably not the best of ideas. One of the best methods of increasing reliability and performance at the same time is installing a larger intercooler or in the Subaru's case a front-mount unit. Knowing a thing or two about intercoolers, the XS crew designed and fabricated an intercooler kit utilizing a GTR-sized front-mount chiller. By installing a front-mount unit heat-soaking, a common occurance with top-mount units, is virtually eliminated. With airflow to and from the turbocharger addressed and cooling chores all handled, it was time to move on to increasing airflow into the throttle body.
XS removed the factory turbo, dissected it and found the turbo was too small to provide the necessary airflow required for big power production. Fortunately XS's research uncovered a turbo that would bolt to the factory manifold. From the IHI family, the turbo features a ball-bearing design for quick spool up, which decreases turbo lag. Last of the performance mods list was installing an A'PEXi Super AFC for fuel enrichment.
On the Dynapack dyno the Subie rumbled its way to the tune of 267.6 hp and 227.7 lb-ft of torque. The crew feels confident they can massage more power out of the engine with the addition of larger injectors; the stockers are near capacity. This upgrade is currently in the works.
From the outside the aggressive bodylines of the C-West body kit and Subaru's infamous rally blue hue teams up to personify performance. The GTR-style rear wing and intense front bumper have been wind tunnel tested to ensure they provide extra down force for better grip at high speed. A set of 19-inch Axis NE-O wheels matched with Falken tires are in charge of keeping contact with the road at all times. Ride quality and handling prowess were addressed by using track tested A'PEXi N1 coil-over and adjustable pillow-ball mounts. Bringing the four-door sedan to a screeching halt are large Wilwood rotors with four-piston Wilwood calipers.
On the inside, the WRX also was improved with the addition of two Sparco bucket seats to keep the driver in place around hard corners. Tunes have also received some upgrades with a Kenwood head unit linked to a Phat noise MP3 processor. A Kenwood amp powers twin 10-inch Kenwood subwoofers mounted in the trunk.
Considering the XS' WRX was built in a mere six months, which includes designing and manufacturing many of the performance products from scratch, the crew really earned its pay. We can't wait to see what the next six months will bring.