well i just got a 2.5' custom catback put on my car (with my already existing custom muffler) and even though i read around the forum that it doesn't really give you much gains, but i have to say i notice gains. Like when my car accelerate it does it much quicker and i see the rpm moving up faster and also just isn't with acceleration even though thats where i feel most of the gains, but also when i'm going form 60-80 or 60-90mph it speeds up much quicker. So i've noticed gains in that. And the car doesn't really sound much loader, all it does is places the higher rpm sounds my car made with its custom muffler and no exhaust system to an earlier rpm stage. For example, the sounds it use to make at let say 5000rpm now makes that sound at 4000rpm or so. So i've noticed that as well.

Also when i got it installed i noticed that the previous owner of the car took off the resonator. So i was wondering this whole time why my car was loud and figured it was the muffler even though my stock muffler was pretty loud, kinda sounded like i had a CAI in it. But now i've gotta go buy a frikken resonator now to quiet my bad boy down

 

i also got a catback exhaust system with 2.5 in piping and a muffler put on mine. and i agree with you i did notice quite a bit of gain, the CAI made it even more noticable though..

 

question when u guys get just the piping doesnt that make ur exhaust have a lard farting noise??? or am i wrong?

 

not necessarily

 

No. Its the muffler and not having a resonator.

 

so if i buy a full catback system do they generally come with a resonator or will i have 2 purchase one??

 

again, it all depends on what brand you buy. the product detail page for the exhaust will specify if there is a resonator.

i can sense next your're going to ask if the exhaust come with a catalytic converter... no, they do not. lots of them come with test pipes