Owner: Import Tuner
Dynamometer Model: XS Engineering
Dynamic Test Systems C-2002 All Wheel-Drive Dynamometer
Testing: Richard Fong
Dyno 1
Baseline
212.2 HP 219.1 TQ
Pros
The Subaru WRX wagon has become increasingly popular among today's enthusiasts since it offers the tuning flexibility of the sedan but the practical capabilities of a wagon. There are few differences between the wagon and the sedan, so there are many interchangeable parts, making the wagon an appealing platform to work on.
Cons
Newer vehicles tend to be averse to modifications and may make or lose power as bolt-ons are added. OBD2 computers in general are designed to protect the motor. Therefore whenever the motor detects gains in power (such as added bolt-ons), the computer tends to richen the fuel and retard timing as a defense mechanism. Over time the factory ECU can "learn" to adjust to modifications and make power, but that's a hit or miss situation. Tuning is always a good way to overcome the shortcomings of factory ECUs.
Notes
This WRX wagon is fairly new and actually baselined a few horsepower higher than other examples we've seen. This could make a difference in the final numbers on the dyno.
Temp
Air temp @ 68 Degrees Fahrenheit
Dyno 2
A'pexi Intake And Aluminum Induction Box
220.9 Hp 226.6 Tq
Pros
The A'PEXi intake is a straightforward install; it simply replaces the factory airbox. The included brackets fit well and are a snap to bolt into place. The induction box's polished aluminum panels are clean and act as a heat shield from the rest of the engine bay. This intake with its induction box made a healthy 8 hp, despite the ECU's attempt to control and possibly limit engine output.
Cons
The induction box install isn't for the novice tuner. It requires disconnecting different harnesses as well as either displacing or removing the daytime running light relay. This process is tedious and time consuming.
Notes
This induction box is well made and has threaded sleeves in place for all mounting hardware. On some occasions, tuning may be required to extract its maximum potential. Even though this bolt-on setup made power, it is possible that tuning would make a greater difference.
Parts
Filter, intake adapter, aluminum induction box, hose clamp, hardware, instructions
Tools
10- and 12mm socket, extension, ratchet, standard and Phillips screwdrivers
Installation Time
60-75 min