Well the short answer is there's definitely huge steps that you need to take. 300 can be (most likely, you'll have to refer to Talon or another Scooby guy) accomplished with simple bolt-ons and a good tune. The 400 mark can most likely be accomplished with a bigger turbo and supporting modifications. And then 500+ is where you start to really get into engine builds, i.e. cams, displacement, stroke mods, etc. The real question is - what exactly do you want in the end. Because now is the time to prep. But I see where the ? is going, so maybe this would be a good point for some of us to outline a basic guide for each "stage". Also, something to note would be are you referring to bhp (brake horsepower, or power @ the flywheel) or whp (hp @ the wheels). In an AWD application, the drivetrain losses are significant therefore it's a pretty big difference. Like I calculate my dt loss @ 25% with my AWD Volvo - makes you feel better
Originally posted by MILOTEKI see these crazy built subbys that have 3,4, or even 500 horsepower. How do they pull this off and whats the quickest route to reach some of these staggering milestones?
Damn quick draw! Nice
Originally posted by talonIVThe best way I know to achieve say 300-360hp is this... 1. Gotta get rid of the TD04. A VF39 or better yet 43 or 34 will do. Also an HTA68 does quite nicely for this. 2. Fuel. Get a wally 255lph high pressure pump and at least get 850cc fuel injectors, you will be needing them. Your OEM fuel rails will do just fine and remember a wideband AFR! 3. 3" turboback, catless up pipe (STi will do nice and be had for cheap.) If you keep your stock exhaust manifold get the grimmspeed crossover! 4. Get rid of that stock 2 port boost control solenoid and get the grimmspeed 3 port. 5. Aftermarket intake. I prefer the SPT or something similar. 6. You can opt for a front mount intercooler or to save money a better top mout will do nicely too! 7. Most important is the right tune! I suggest such big fuel injectors because you will be running E85 to reach this power level on the turbo's listed above. I prefer an opensource tune. The only equipment you may have to buy is the tactrix cable but a good reputible tuner should have his/her own. Remember this is on a stock block too, that is about as much power that a WRX will handle stock. Which reminds me... get that aftermarket clutch too! I know this list sounds pretty simple but you would have plenty of fun with that set up. If you want to go even higher I would start looking into doing away with the EJ205 2.0 and step up to the EJ257 from the STi with your WRX heads. Go with forged rods and pistons, Subaru's are known for weak pistons! Bigger cams to go along with a bigger turbo (ie, GT35R). You will probably want to do away with your 5 speed and snag the drive train from an STi or Legacy GT (Model years 05-08 for the Legacies) as they are stronger then the WRX transmission. Depending how much power you want will determine your tuning methods. I love open source, ACCESSport is awesome and stay away from piggy backs. If you are trying for huge numbers look into AEM for stand alone engine management, especially for custom setups. This should give you a good idea on what to reseach and look into for whatever your end goals may be. For some unknown reason it seems to be a bit harder to make good big power in Subaru's then say an Evo or DSM. But it can be done and its fun!!! I do miss my WRX.