well, you can lose low end torque, BUT gain high end

 

I've been happy with the changes a cold air has made on mine, I don't know about any power gain or loss, but over all it feels alot better. you sure you aren't thinking about the turbo's and intakes?

 

i am a hundred percent sure that it is about the 2.5 n/a

if you get it tuned, then its better, but otherwise you only gain like 2 up top and lose like 5 lbs of torque on the bottom

 

you would be suprised...

 

hey everyone, im new to the subaru family, i just bought a 2007 impreza 2.5 i i know alot has benn covered as far as some mods, im gotten a little advice on the forum but then i found this one specifically for our cars. so does anyone have general advice on what they have tried that worked well or looks good? body, rims, intakes, adding a turbo, anything really. thanks

 

so i was looking at high-flow cats and exhausts and i wanted to know...what are some good brands for HFC's?

on this site i found 2 (stromung and random tech) and i wanted to know if either of those were a good choice?

http://64.71.53.59/exhaust.htm#Exhaust%20Catalytic

 

they won't fit on the 06s and up. HFCs don't give you much power for non turbos. they make it sound really ricey too.

 

they should fit.
you just have to fabricate it.
it won't be a bolt on, just weld it.

 

do they make a HFC for our cars yet? or welding is the one option?

 

Unless you want a loud car, i wouldn't bother with a HFC, like bet said they won't add anything of note to our NA's

 

has anyone in here tried shaving the heads? if not, how much do you think is safe?

 

ok 6 days later and no reply...
bump much?

 

ok dead thread...
i was trying to decide between weapon r and injen intake. Does anybody have any suggestions? it gets around 110 degrees here in the summer so is a CAI a worthwhile investment? Also, are the lightweight crank pulleys worth it? thanks a bunch yalls

 

i just bought the injen CAI and am currently waiting for it to be delivered...

as for the pulleys they are worth it because the cut down on driveline loss due to rotational mass...so it wont make more HP but it will allow more hp to hit the wheels (not much though)

 

I ran mine (Injen) as both cold and short, and i noticed alot of time when i had it in short that i'd get a good delay when taking off from a dead stop that i haven't noticed since i switched over the the sold

Pullys also pay of more as you increase your power more and more as well