Ok.. so i'm pretty much set on the zzp mid-length combo.
I have the GMPP performace exhaust (mods in vbGarage) and and i LOVE the way it sounds, but i need to open it up a bit..
so this is what i was thinking:

1 3/4 hi temp w/ 3" catted downpipe to 2.5" exit, bolt in??

or should i stick with a 2.5" catted??

idk.. I'm just worried about how it will sound.. i don't want an extremely loud
and obnoxious, raspy sounding exhaust.. i do want it to be deeper but also a little louder, but not a bunch..

What do you guys think? Any input is appreciated!!

Thanks Guys

 

i have a vibrant 3" catless dp
but stock catback lol
i plan on getting a catback some day but for now it sounds stock just
a lot louder not deeper and not any more raspy
i like it

and as for headers my choice is the jbp vortex octopus header

 

How is the vibrant? I'm wanting to get the Vibrant header with downpipe and high flow cat in mine. But I wanna know how it is, any leaks or anything?

 

vibrant is WAYYY too much... you can have a resonator welded in at a local muffler shop for like 70 bucks (thats weld + resonator) and it will make it sound like a vibrant... because thats all it is.. it has resonators to take out the rasp...

Im catless, with a 3" dp, 2.5 exit... unless your hitting over 300 or so you should stick with the 2.5" exhaust... 1.75" primaries are good with the 3" dp, but the velocity isnt high enough to support a full through 3" exhaust... if your over 300, then switch to the 3"...

The answer to the raspyness question, hands down, is RESONATORS!

 

vibrant header and hiflow dp dont eliminate rasp.

I have both and when i slapped on the GMPP sport exhaust it was raspy above 3000 rpm. Sounded low and mellow below that.

I took out the gm resonator and slapped on 2 glasspack resonators reversed to muffle it and it sounds low and mellow all the time. Cost 140 i think total...mostly because of the resonator price.

The header will need to be tightened over the course of 2 weeks so the exhaust manifold gasket will conform to the new header. It leaked like hell the first couple days but if you do it slowly during the course of a week most of it will be gone, then the touch up for the end of the last week to eliminate it entirely.

 

Precisely...

 

id go with that zzp set up but also i would get a bigger catback to help out.. 3" dp tp 2.25 catback?

 

Go with the Clear auto Image header/dp....excellent quality!!!!

 

2.25 catback? Thats too small.. 2.5" is good.. 3" catback is too big, but the 3" dp to 2.5" catback is a good setup.

 

yeah 3" dp to that small catback is crazy

 

.....why is it crazy?

I beg to differ. The 2.5 is a little on the large side for an m62 based off my dynos.

 

i ment why go from a 3 inch to a 2.25? if your saying that 2.5 is a little big .. whats 3" lol

 

no the effort was to get the most velocity out of the exhaust system. I was working on the physics of it.

 

no... 3" is a little big without 300hp... 2.5 is perfect for a stage 2 tuned car....

 

is true, rest debatable and i dont feel like getting in to it.

 

do you guys pass inspection with your downpipe? i know in alot of states ,its illegal to modify ur exhaust at all, but mines actually not THAT loud, but im def doing a downpipe soon, but jw if u guys get hassled.

 

just get all 2.5" like stated its a good size.... you could sell that gmpp for good money too gl with what ever you choose tho

 

yea and well probly both say the same thing phantom, but its just easier to say it that way than it is to really get into it.. haha....

i live in fl with NO inspection... so im good to go! Really its a money issue... the high flow cat you get with aftermarket dp's restrict only like 1 to 2 hp... if that... not noticeable... but its an extra 150 bucks or so...

if you can dish out the money for it, and have to worry about inspections, just get the cat... less likely to throw the code... If you do throw a code, have someone with hp tuners tune it out, because sometimes thats all they base the inspection off from.

 

I have the Clear Image combo, 3" downpipe, high flow cat.........been on the car for about a month now, no codes, no install problems, no leaks, no chance of the downpipe breaking........quality is excellent.......I would personally recommend them, not one person has had a problem with their stuff yet!!!

 

Me either.. i love their stuff... you should really look into it...

http://www.clearimageautomotive.com/Chevy%20Cobalt.htm

 

meh.. CIA and Vibrant are a little over my price range, although their quality is superb, from what i've heard.

I guess i agree with what was stated earlier about going from a 3" downpipe to a 2.25" catback would be "unsafe", for lack of a better word... sounds logical.

to the next problem: sound

1.75 primaries to a 2.5" catted bolt in w/ gmpp sport

i do want it louder but nothing too obnoxious.
What do you guys think?
once again, any feedback is appreciated. and vids couldn't hurt lol

Thanks yall



EDIT: CIA isnt really that bad.. actually quite comparable to the ZZP. hmm.. haha

 

You got it wrong.. i think going from a 3"dp to a 2.5" exhaust is fine...

3"dp to 2.25 is too small... but 2.5" is just fine...

Cia is wayy cheaper than vibrant if you go with the standard metals... its all depending on what you wanna do about it (stainless or just aluminized... which is less expensive)

Personally i woudlnt go with the 1.75 primaries unless your gonna do the 3"dp, keeping the 2.5" catback.

 

why is a 2.5" catback "unsafe"

 

thats why i think he read it wrong.

 

Just Stick With 2.5" Catted Imo...you Will See Increase In Power