question: exaust system

[kb02gt]

after having just read this article called Lung Transplant (about exhaust systems)

these guys had 40kPa of back pressure created by the cat, resonator, and muffler.
they brought it down to 10kPa using a different cat, getting rid of the resonator, and using a different muffler.
is this enough back pressure? (i thought you needed back pressure) how much do you need anyway?
can the same results be accomplished using a highflow cat, and a magnaflow straight-through muffler (i'm willing to bet our stock system has at least 40pKa of restriction, not sure though)

and after reading every thread i could find on the subject, both on this site and the old. I'm still a little confused. :(

I've read that the muffler is supposed to only help quiet the car. But then i've read that it can also be very restrictive, reducing any gains.

All i'm really looking for is something that is not too restrictive so i don't lose any power, but isn't too loud either. But then i've read that you need a certain amound of back pressure.

and of course a silencer would be out of the question.

also, what is the diameter of the stock catback?

any help clearing this up would be greatly appreciated. my apologies for asking a million and one questions. i just want to get it right.

[2004ElantraGLS]

I'm not too sure about the Backpressure issue. But I do know that most people here seem to like the idea of a 2.25 exhaust(mandrel bent), a high-flow cat, a magnaflow resonator, and a magnaflow muffler. That combo seems to keep things quiet yet allow for good exhaust flow and a faster revving motor, especially when combined with a good Header. This system is what I'll be using, but it'll be a while before I can do it. Right now I just have my stock muffler removed. It sounds great, but the cabin noise is a little too high for comfort.

Axel

[kb02gt]

that sounds like a pretty good set-up, but would you really need the resonator since its restrictive (although not too restrictive)? Or is just for the deep growl they help resonate?

Ford has no cats on his car with what appears to be a stock muffler, wonder what that sounds like?

in the article they used only one high flowing cat, and the muffler was off a nissan r33 skyline. and no resonator.

i'm starting to think that the restriction of the cat they used which was from a [VL-onward Holden Commodore] would be equal to that of both the high flow cat and resonator you plan to use. and that maybe the magnaflow straight through muffler flows better than the one they used which was from the skyline. (although i'm not real certain about all that) it just seems like the louder it is the better it seems to flow.

i believe they used 2 1/2 inch piping.

according to them, the sound was just 2-3dBa above stock. which is about what i'm aiming for, maybe a little more.

[2004ElantraGLS]

The set-up that I described will prevent my car from making that pissed off bumble bee sound. If you go with a Header, a high flowing resonator will help turn that Header-buzz into a low rumble. The only reason I'll be using a high flow cat is to prevent the CEL from coming up.

Axel

[kb02gt]

okay, i think i get it. But couldn't you also use an O2 simulator, and get rid of the cat? or do you think that might make for an even louder sounding system?
might do this if not.
thanks for the replies by the way.

okay, nevermind, i just read this thread again:

http://www.elantraxd.com/forums/showthread.php?t=1032

and have decided i'll just go with the high flow cat, resonator, and magnaflow muffler(not sure which one yet, maybe the straight through)

thanks for the help bro

[Jameson]

With no cat and no resonator and a straight through muffler, it will be loud as hell and will sound like bumble bees on crack cocaine. I highly suggest using a free flow cat and a glasspack style resonator as it will keep the bee sound to an absolute minimum.