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Subaru WRX STi - Power Pages

Subaru WRX STi Performance

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Subaru Wrx Sti Hood Scoop View

Owner: Crawford PerformanceDynamometer Model: Dynapack Evolution 4000 DynamometerEcuTeK Tuning: Bill Knose

Dyno 1baseline332.0 HP 341.5 TQ

ProsWe baselined the EJ25 2.5-liter engine knowing power figures would be slightly higher than factory form. This is attributed to the vehicle's Helix 3-inch stainless downpipe with DNA Series High-Flow catalytic converter and Crawford Performance-modified tumble generator valve deletes (TGVs). The remaining components on the vehicle are stock.

ConsCrawford Performance provided us with a "mule" WRX for our Powerpages. The engine was still in pristine condition with only 10,000 miles on the odometer. The only drawback was the vehicle's body condition: It had it been through hell and back.

NotesThe Dynapack 4000 Evolution dyno numbers reflect flywheel horsepower and torque figures.

TemperatureAir temperature: 82.2 degrees Fahrenheit

Dyno 2EcuTeK329.9 HP 375.8 TQ

ProsYou'll notice we lost a total of 2.1 peak hp to baseline. But, if you pay close attention to the dyno chart's horsepower, you will notice healthy midrange power gains from 2400 to 5350 rpm. Bill Knose from I-Speed, located in Oceanside, Calif., did the EcuTeK tuning, and the STi responded well. At 3500 rpm a whopping 40 hp were gained over baseline. Torque numbers jumped 56 ft-lb at 3600 rpm and continued to dominate throughout the midrange.

ConsTuning the EcuTeK unit is licensed though an authorized dealer and tuner. That means unless you're a dealer or are looking to perfect your clepto skills and swipe a program from some local shop, tuning is off-limits to consumers.

2015 to 3500 HP range: -2 to 45 2015 to 3500 TQ range: -4 to 58
3500 to 5500 HP range: 40 to -7 3500 to 5500 TQ range: 58 to -3
5500 to red line HP range: -7 to -16 5500 to red line TQ range: -5 to -10
Peak HP 329.9 Peak TQ 375.8

NotesWhat is EcuTeK? Simply stated, the EcuTeK is the remapping of the factory computer (ECU) though the factory OBD port. The main highlight of using the EcuTeK over standalone computers is it eliminates using additional sensors or having to splice into the factory ECU harness.

Tuning Time5 hours

ToolsNone

TemperatureAir temperature: 83.2 degrees FahrenheitTemperature difference from previous run: +1 degree Fahrenheit

Dyno 3Hayward & Scott3-inch stainless-steel exhaust339.0 hp 385.7 tq

ProsWhile many exhausts sold on the market today tend to come off as raunchy noise-makers, the Hayward & Scott unit is a surprisingly quiet exhaust system. Don't be under the presumption that just because it's a quiet exhaust, it will falter in the power department. This all-stainless-steel unit quiets all you doubters out there, as it posted a 6- to 10-hp increase from 3000 rpm to 6500 rpm. Torque numbers were equally impressive as 20 ft-lb of torque were recorded at 3300 rpm.

PartsMuffler, B-pipe, gasket and U-clamps

2015 to 3500 HP range: -2 to 50 2015 to 3500 TQ range: -2 to 78
3500 to 5500 HP range: 50 to 8 3500 to 5500 TQ range: 78 to 7
5500 to red line HP range: 8 to -4 5500 to red line TQ range: 7 to -3
Peak HP 339.0 Peak TQ 385.7

ConsMinimal complaints can be said about this exhaust, except for the fact that this was the first unit delivered to Crawford Performance. As such it sported a rough finish and prominent weld marks. Crawford informed 2NR that the final production unit will address these problems before it goes on sale within the next few months.

Installation Time60 minutes

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