Does a full catback exhaust add alot of hp?

[SilviaSR20DET]

I own a 97 240sx automatic and im planning on purchasing a full catback exhaust such as the hks hiper or the apexi n-1. How much hp and torque do they add and if it really makes a difference in an automatic car. I have an injen intake (short ram) installed and so if i add a full catback exhaust would i feel a dramatic increase in power? thank you

[Natty]

It should add somrhting you'll feel when coupled to a new intake and headers.
The best performance you can get for the buck would be a 5 speed tranny though.
Jeff

[West]

s14s tend to gain a little more from a cat back than a s13 due to the factory exhaust designs.

I think the most ive seen gain from a catback on a NA car was about 7rwhp from a 5Zigen exhaust off a s14. Could be ones that give more, but I havent seen any dynos from them.

Ive never seen a decrease in TQ on my 5spd's when adding an exhaust to a 240sx even when I added a dump pipe. I felt more of a TQ loss with my Injen Intake then any exhaust system. I dont think you need to worry about TQ loss unless you get a 3" exhaust for a turbo setup.

Of course it will help out once you get other mods such as Intake, Exhaust, ECU, etc.

If I find that Dyno of the 5Zigen I will post it for you.