Realistic Numbers

I am BRAND NEW to the Subaru World. I just bought an '05 Legacy GT Wagon 5-speed. I have no idea about Japanese performance. I have a high horse power '96 Mustang GT so I know about performance, I just have no idea about import performance. I only bought the car to have a 4 cylinder all wheel drive to get back and forth to work. No idea they were this much fun. My question is if I do a

 

1. Cobb UP pipe

2. Cobb catted Down pipe

3. Borla Cat Back

4. Cobb short ram Intake

5. Cobb Access Port

6. Cobb Blow Off Valve (just 'cause it sounds cool)

 

how much Horse Power to the wheels am I realistically looking at gaining? Will I need to get it dyno tuned at this point or can it be an off the shelf tune? My goal is just to get the maximum air flow and have it running efficiently. I don't need another RACE CAR, just wanna have it breathing freely without pushing any parameters on reliability.

No need for intake at this level. You are basically just doing a Stage 2 setup with that parts list.

 

You can use an OTS tune but it is highly recommended you get a pro-tune: either a dyno, street, or e-tune.

 

For starters I would read over these threads. Should help you get a pretty good idea of the kinds of gains you will get with your planned mods:

Turbo Powertrains: Tech Reference

Cobb Accessport & ECUTek info

The Official Tuning Thread

 

And in case you decide to go with an e-tune of some sorts this will help even though it is for Open Source tuning instead of AP tuning:

The COMPLETE beginners guide to e-tuning (with a vendor and VAG-COM cable)

 

And lastly - Welcome to the forum

You would be looking at a gain of around 40-50 AWHP with those mods. The intake and blow off valve are not necessary with that list, so you could skip them and save a few hundred $, but if you want them for the sound then go right ahead! An off the shelf tune is fine (Stage 2 Cobb), but a custom e-tune or dyno tune will probably get you an extra ~10 HP.

^ Beat ya!

damn you Brendan!

Thank you for the quick replies fellas! I appreciate the Input. I am scratching the Intake and the blow off valve (even though it sounds cool). I'll take your advice and go with the Pro-tune just to get the maximum out of my mods. Will I be drastically hurting my MPG at this point?

No, at least not significantly as far as I am concerned. Wouldn't be enough to bug me.

 

The biggest issue when it comes to hurting your MPG is how heavy your foot is.

NWSPECB, that's good to hear. I still want decent MPG for commuting. With these mods will I be around 280 HP to the wheels?

closer to 240

ehhhh I think you'll be closer to 240ish. I could be wrong though. It also depends alot on the tune if going with a pro-tune. Like Doc said a good protune could get you an extra ~10hp.

 

The real way to think about it is whether or not you are having fun with it. You will notice a big difference between stock and stage 2 levels. I would even start with just an AP and go with a stage 1 OTS tune for a few days so you can experience the increase in performance between stock and stage one.

 

Another thing to think about - have you thought about upgrading any of the suspension bits? Sways and endlinks aren't too terribly expensive and make a world of difference.

 

Edited hp gain estimate because Brandon is smarter than me.

You are basically doing exactly what I am in the process of doing. It sounds like your budget isn't quite as tight as mine so since you aren't going with an intake or BOV I would look into aftermarket top mount intercoolers. Our stockers tend to blow the end tanks off at stage 2 power levels, plus having more cooling will give you another 10-20hp depending on which one you go with. Or you could go the budget route and do either a JB weld or Bullet Proof mod, as I am.