I've got an 05 WRX. I'd just like to get your opinions on how much power you can extract from the 2.0L powerplant w/o changing the internals of the engine and turbo. Probably have to change the up-pipe and down-pipe along with getting a TBE. Also, put a new intake on it. Has anyone done this? And how much power did you get out of it?

 

WIth a catless exhuast and engine management, you will increase about 40-60 hp more than stock...depending on dyno, tune and gas. Dont worry about intake or BOV unless you are upgrading the turbo, using a front mount intercooler or have some crazy hp setup. The stock airbox works good.

Lots of people have done this stuff, those are the standard/proven power mods to do first.

 

I just got my car dyno'd at Buschur Racing (mainly Evo's) and I pulled 140 whp and 150 lb-ft on its Mustang Dyno. That doesn't seem like a lot. The car's quick but just not quick enough. I think you're right that a tbe and em are the best first mods. They're relatively inexpensive and can pay big dividends.

 

While results will vary, even among dyno's from the same manufacturer, a Sacramento member recently put down 181whp/185wtq on a Mustang dyno. He has an uppipe and Cobb Accesport on an 05 WRX wagon. That should give you some idea as to what the mods will do for you. On that dyno, stock WRX's usually come in at 150 or 155 whp.

I had an 02 WRX wagon that was pushing 250 whp. It had a VF30 turbo, injectors, fuel pump, larger TMIC, TBE, uppipe, and ECUtek reflash (on crappy Kalifornia "91" octane). I felt it was quite safe. There are others out there who have pushed 300 whp on the stock internals without issue.

As for first mods, an uppipe should be first. It is the most bang for the buck (see 05 wagon above). Get an engine management system that is easy to modify as you add more components to the car (i.e.: TBE). I would recommend the Cobb Accessport. While they have off the shelf maps available for download, your best bet is to find a tuner local to you that has Cobb ProTuner which will allow him to custom tune your Accessport.

And remember that peak numbers on a dyno chart don't tell the whole story. Even though an uppipe and EM may only add 30 whp, they drastically change the hp and torque curves. You will feel that 30whp much more you would think.

 

I wanted something quiet and factory-like but with more power. I essentially have the factory exhaust on my car (minus 2-cats) and all performance bolt-ons. Mike @ Gruppe-S tuned my car back on December 23rd and got me (200.4 whp / 194.9 ft-lbs). Mike told me that it was at 180hp just with COBB's base-map and my mods before he tuned it. Stock WRX's make about 150-ish on their dyno.

My mods are:

COBB AccessPort with cusotm ProTune
Bosal Up-pipe (999-391)
Prodrive center pipe (3CE)
Vishnu Power Pulley Kit (underdrive pulley)
Vishnu silicone intercooler hoses (black)
K&N drop-in high performance air filter for factory airbox
GPMoto elbow intake (PN 11304)
STI (OEM) axleback muffler
WRX (OEM) downpipe and midpipe

It's very noticeable difference on my 2004 WRX...

 

The car definitely needs some sort of EM. While dynoing, it was running extremely rich (~9) esp after 4k rpm. I was checking out other people's runs (modified EMs) and their AFRs were much better at 10.5-11.5. I'd like to get it ProTuned because I saw that with just a little time a friend made 40 hp on tuning alone. Plus, I'd be getting better gas mileage when running leaner.

 

I was thinking of putting on a Borla Hush cat-back exhaust along with a good up- and down-pipe (w/ high-flow cat). I need to pass emissions. And, then get a Cobb AP w/ ProTune. It's not too much money and it'll put out a lot more power.