The turbo itself has max psi of around 21-22 psi. The stock hardware on your car calls for a stock tune of 16 psi. If you went stage 1 you'd get about 18 psi on your tune. If you went stage 2 about 21 psi.
Turbocharged versions of the 2.0- and 2.5-liter engines were offered in the WRX and WRX STI models. WRX models featured a 2.0-liter turbocharged boxer engine until 2005, after which they switched to the 2.5-liter turbocharged engine.
The WRX can do 0-60 in 5.4 seconds. With simple bolt-on parts (bolt-on meaning you don't have to take apart the actual block or heads), we can increase the horsepower of the WRX (either standard or STI) to over 400. This will make the car faster than nearly anything on the road.
The 2.5-liter four and all-wheel driveline are the only mechanical carryover pieces, and in the WRX, the 224-horsepower intercooled turbo engine's torque peaks at 2800 rpm, down from 3600 rpm, for better performance.
Subaru adopted the name "WRX" to stand for "World Rally eXperimental" as all WRX versions (1992 to present) feature rally inspired technology, including all wheel drive, stiffened suspensions and turbocharged four cylinder engines.
This provided for more accurate tuning to wring the most out of the new hardware. Right away, the STI realized a 16.44 peak wheel horsepower increase and 15.74 lb-ft increase in torque. This brought the peak numbers up to 366.12whp at 5,050 RPM and 413.03 lb-ft of torque at 4,300 RPM.
There are two 2019 Subaru models that are powered by a turbocharged BOXER engine WRX and Ascent. Subaru WRX: The Subaru WRX features two turbocharged BOXER engines. The WRX is powered by a 2.0L turbo four-cylinder with 268 horsepower and the WRX STI utilizes a 2.5L turbo four-cylinder that generates 210 horsepower.
WRX has a more efficient / better engine which equates to better mpg and reliability. I've heard the wrx engine does better with mods and can actually handle higher horsepower than the STI. But honestly, if high horsepower is highest on priority list, you're really looking at the wrong cars
Subaru WRX vs Subaru STi
| What are the differences? | Subaru WRX |
|---|
| 0-60 Time and Top Speed | Manual: 5.2 Seconds Automatic: 5.7 seconds Top Speed: 155 mph |
| Rear Spoiler Subaru says the park bench on STi adds 3mph to top speed and increases stability at high speeds. STi can be ordered with the WRX lip spoiler. | Subtle |
Engine, Transmission, and Performance
The WRX STI's turbocharged 2.5-liter flat-four is eager to rev and pumps out a characteristic flat-four burble from the car's quad exhaust pipes.The flat-four in the 2015 WRX is a member of the FA engine family that powers the turbocharged Forester XT and the naturally aspirated BRZ and Scion FR-S. Direct injected, the engine inhales 15.9 pounds of peak boost (or slightly more during brief overboost periods) and has a 10.6:1 compression ratio.
The WRX's 2.5-liter turbocharged boxer four still features maximum boost pressure of 14.2 psi and produces 265 hp at 6,000 rpm and 244 lb-ft of torque at 4,000. The STI engine, with 14.7 psi of boost, remains rated at 305 hp at 6,000 rpm and 290-lb-ft at 4,000.
a 20g is a Mitsubishi Heavy Industry turbo that is available in a TD05 (similar to your stock exhaust wheel) or td06 (larger wheel). It flows about 44lbs/min and can make 400hp.
Here, you are looking at the Subaru OEM IHI VF52 Turbocharger. This is the factory turbocharger that came equipped in the Subaru WRX from 2009-2012 models and makes for a nice upgrade over the factory turbocharger.
Subaru's Rally Fighter is Better Than Ever, But is it Good Enough?
| 2015 Subaru WRX STI |
|---|
| BASE PRICE | $38,190 |
|---|
| VEHICLE LAYOUT | Front-engine, AWD, 5-pass, 4-door sedan |
| ENGINE | 2.5L/305-hp/290-lb-ft turbo DOHC 16-valve F-4 |
| TRANSMISSION | 6-speed manual |
2015 WRX Horsepower Record - 564 Wheel Horsepower - P&L Motorsports.
2.0L Turbocharged four-cylinder BOXER:
The turbocharged 2.0L four-cylinder BOXER powering the WRX generates 268 horsepower and 258 lb.Built for time attack races, this is for sure the strangest Subaru Impreza WRX STI I've ever heard! That's because it's powered by a twin turbo EJ20 engine, one turbocharger for each engine cylinder bank.
2017 WRX New Car Test Drive
Both versions come as a sedan, a hatchback isn't available. The WRX uses a turbocharged direct-injection 2.0-liter boxer four-cylinder engine with a twin-scroll turbocharger, making 268 horsepower and 258 pound-feet of torque that comes at 2000 rpm and lasts until 5200 rpm.Even though the Subaru WRX STI performance sedan is the least-reliable vehicle in Subaru's all-wheel-drive stable because of its EJ25 2.5-liter turbocharged Boxer engine, it wasn't too much to keep the new 2019 Subaru Ascent, Forester all-wheel-drive SUVs from pushing the brand to the #1 Best Car Brand ranking in 2019.
In the WRX STI, a bigger (2.5-liter) turbo four generates 310 horsepower and 290 pound-feet, mating with a 6-speed manual transmission.
WRX models featured a 2.0-liter turbocharged boxer engine until 2005, after which they switched to the 2.5-liter turbocharged engine.
Subaru's 2.0-liter turbocharged, horizontally opposed four-cylinder "boxer" engine continues to power the 2016 WRX model in all three trim levels. Its 268 horsepower and 258 pound-feet of torque are directed to the all-wheel-drive system through a standard six-speed manual transmission.
WRX trims feature a 265-hp turbocharged 2.5-liter horizontally opposed four-cylinder engine paired with a five-speed manual transmission.
WRX models featured a 2.0-liter turbocharged boxer engine until 2005, after which they switched to the 2.5-liter turbocharged engine.
Here, you are looking at the Subaru OEM IHI VF52 Turbocharger. This is the factory turbocharger that came equipped in the Subaru WRX from 2009-2012 models and makes for a nice upgrade over the factory turbocharger.
The 2010 Subaru Impreza WRX is much more powerful than the previous models, which Edmunds reviewers attribute to "a larger, STI-based turbocharger, wider-diameter exhaust and less restrictive catalytic converter." Cars.com finds that the engine on the Subaru Impreza WRX is a "265 horsepower, turbocharged 2.5-liter four
The engine can be mounted lower in the vehicle than other engines, and weight balance on the left and right can be made almost exactly the same. The new generation BOXER engine, FA20, now comes mounted with Subaru's first direct injection turbo.
The 2014 Subaru Impreza WRX is powered by a turbocharged 2.5-liter boxer engine good for 265 horsepower and 244 lb-ft of torque.
WRX models are powered by a turbocharged and intercooled 2.0-liter engine that generates 227 horsepower.
Basically, each piston in a boxer engine gets its own crank pin, so the pistons opposite each other move together. The fact that these pistons move together, like a Boxer's gloves, is what gives this engine type it's name.
Routine maintenance is fairly easy. The engine bay is easy to get around in my opinion, but it may take some getting used to. Naturally aspirated (non-turbo) engines are generally easier to work on as there are less components at play and more space under the hood.
