what a difference!

[explicitone]

Originally posted by xxxBlakexxx
It's your car. Make it the way you want. Everyone has different goals and situations.

Catbacks can add measurable power. There is some great info at Mach 1 registry where three different catbacks were tested on an otherwise stock Mach 1. SLP and Magnaflo were two of them I believe. The gains were 8 - 12 hp as I recall.

Plenum and TB combos are a proven 10 - 12 hp. There has been tons of studies done on these...it's a no brainer. You have to decide if the $350 for both is worth it.

I also must agree that gears such as 4.10's are a great mod. They will make the car feel more like a 5.0 by adding power down low and make the car scream that much more at peak.

So, here is a list of common mods, price and hp gains:

1 - Catback...$300 - $500...10 hp
2 - Under Drive Pullies...$200 installed...8 hp
3 - Plenun/TB...$350...10 hp
4 - CAI...$80 - $250...0 - 8 hp
5 - 4.10's...$500 installed....0 hp (but seems like 40 hp)

1 thats a 4v not a 2v the catbacks on a 2v maybe 5hp max
2 I only seen 4hp on a dyno form my u/d pullies(same day dyno)
3 togather you might see 10
4 cai save your money they are only worth 2-3hp and you can get that from a drop in k&n

now put them all togather then yes you see some gains

and headers unless there longtubes on the mod motors are not worth it and no you wont gain 15hp headers on the stock long block