Dyno Test Results
Carefully monitoring the vehicles air/fuel ratio and ignition maps with a laptop, Buenas made a few dyno pulls as he modified the factory ECU's maps in order to optimize and achieve a safer ECU map to work with without having to worry about grenading the engine. The tuning had worked its magic on the STI as dyno figures show a smoother graph from its initial pull to redline while netting us with a gain of 34 whp and 27 lb-ft of torque

Product
Intake, Ea nano-fiber dry filter, 2 3/4 straight hose, fenderwell heat shield, powerbands, 18-inch foam rubber trim, m6 vibra-mount, m6 flange nut, m6x12mm hex head bolt, fender washers, m4 x10mm bolts, instructions

Installation Time
20 minutes

Injen Intake
ProsWith the '08 STI still new to the market, Injen Technology was able to pull a few strings and ship their newly developed intake for our vehicle testing purposes. Using what they refer to as MR Technology "the world's first tuned air intake system", Injen representative's state the intake was designed to run factory safe air/fuel ratios for optimal performance. Within 20 minutes we were able to remove the factory intake and replace it with the new Injen unit. We liked the fact that the simple, yet effective design of the pipe was engineered to use a fender head shield and foam rubber trim to reduce intake temperatures.

Cons
Vehicles using a MAF, including the Subaru, rely on the MAF curve to be calibrated to the intake on the car. Diameter changes to the pipe, including aftermarket air filters, can drastically affect the tune and air/fuel ratio on the motor. As you recall with our '08 STI, we decided to reflash the ECU with a tuned map before installing any aftermarket parts. Using an Innovative air/fuel monitor, we found when adding the intake that the unit had leaned out the engine by approximately 0.75 air fuel ratio. Our goals from the first initial pull on the vehicle was to test and tune every part installed to ensure the maximum potential each product offered and give our readers a realistic idea of what to expect.

Dyno Test Results
The Injen intake with tuning didn't disappoint as it picked up both horsepower and torque from its initial pull till redline. The dyno graph revealed a gain of 20 lb-ft of torque at 3,200 rpm. Promising numbers were recorded at 3,750 rpm as a pickup of 15 hp and 20 lb-ft of torque were recorded over our previous tuned baseline run. A solid gain of 15-20 whp and 10-17 lb-ft of torque was obtained from 4,350 rpm to 6,600 rpm as the graph neared redlines.

Product
Exhaust, midpipe, bolts, nuts, gasket flange

Installation Time
70 minutes

Greedy Se Exhaust
Pros

GReddy stepped up to the plate and offered to test their Spectrum Elite (SE) exhaust system on the '08 STI as the exhaust was a soon-to-be-released unit during our time of testing. The SE system uses a 70mm diameter piping, which terminates into their free-flowing exhaust canister. Flame-treated tips give the SE exhaust its own unique look while adding some added flair to the STI. Along with its aggressive appearance, the exhaust has been designed to emit a legal 95dBA decibel rating, which ensures cops won't harass you on the streets.