Most things are gonnacost a couple hundred including labor unless done by yourself. Some people have their beliefs on certain things as well. You can get a dual exhaust and tap on an x pipe or h pipe, throttle body and throttle body spacer (different opinions on that), my tuner was around 400 and I could feel a difference automatically, t lok or 8.8 rear end, headers, pulleys, gears. No matter what it's a pretty penny to fix up your car. I usually hear increasing the air flow is the best thing to always start with. Good luck!
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05 GT, K&N CAI, Magnaflow Exhaust, TB Spacer, Kooks long tube headers, and Kooks o/r x pipe
if you havnt done your exhaust yet do that (look through the threads theres alot on them), dont get a throttle body spacer, t-lok and gears are always great mods though
CAI = 2-4 rwhp
TB Spacer = 0
TB = 0
TB on ported intake(s) = 2-4
Intake Spacer = 1-3 rwhp
Ported Upper/Lower Intake = 8 ish rwhp
Ported Heads = 15-20 rwhp
Cam = N/A (depends on aggressiveness) 10-15 is a good range for a mid rated cam
Headers = 1-2
Long Tube Headers = 5-6 (make sure to use a catted mid pipe)
Exhaust (mid pipe back) = 7 rwhp
Gears/Differential = 0 hp, but good gains are made with these
Tuner = 5-10 rwhp (depends on tune quality)
N2O = 50/75/100/150 rwhp (depends on boost taken and quality of tune)
S/C = 75ish rwhp on 6-8 psi
All in all you make your choice as to what's garbage and what's not. If 2-4 rwhp sounds worth it to "you" then do it, if you'd rather get the bigger 50+ rwhp gains, then go that route.
cheap ways to gain hp
