Alright. Just a few questions guys

This is my first time modding any sort of exhaust on any of my cars, especially F.I.


So i put the zzp shorty header, and 3inch downpipe which bolts up to my 2.5 stock exhaust. I do have a high flow car as well.

Now my question is, I find the car alot louder.. and more rumbly.. is that dude to the stock exhaust? or just the down pipe and header in general? it is alot louder then stock, which i was expecting... ??

My mods are Gm Stage 2, injen intake, and zzp shorty header and 3inch downpipe attaching to my stock exhaust..

 

Yeah, wait till you put an after market exhaust on there, ull be setting alarms off

 

thats how its gonna sound with a catback exhaust...our stock exhausts are restrictive at all..only part thats restrictive is the one's u changed,so now its a free flowing exhaust..u might get a little more rumble and bumble with a aftermarket catback,but wont be a big diffrence

 

Not really...

 

alright, so i was out driving my car tonight.. went out for dinner.. it seems after it has been sitting for a while and cools down... as i start driving, it sounds normal, but as i keep driving it gets louder.... \i know that it must expand, but how loud does a the zzp shorty header and 3 inch downpipe with high flow car sound.. IT SOUNDS LIKE I HAVE MUFFLER RATE BELOW MY SHIFTER! LOL... ANY IDEAS? IAM STILL BOSSTING THE SAME, I AM THOUGHT IT WOULD BE MORE QUIETER THEN THIS...

anyone?

 

You could check the seals on the gaskets. If one of them didn't seat properly it'll sound like a rice-box. Happened when I first installed my GMPP cat back.

 

I hope to god that you changed out the header to downpipe bolts, nuts, and washer. If you didn't, it is going to snap within a month.

 

Really........ Mine have been fine for 4 months now....

 

can someone here lay to rest a question ive had about the zzp header dp combo (im actually looking to get the midlength header/dp). ZZP tells me to expect a 30hp (25whp) gain with this mod alone with my setup. has anyone here got dyno results to support this claim? what do yall think is the gain with my setup?

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06 cobalt ss/sc, G85, Injen CAI, GM S2, 2.9, DP +Opt.B, NKG7RE, Hurst STS

 

had mine for a year now like this and it hasnt snapped yet

you actually believe headerrs and dp will give you 25whp? more like 10-15

 

you got a header, and a 3" downpipe, of course it's going to be loud as hell.

and whoever says the stock exhaust is not restrictive, guess they have never looked at that nice crush bend that goes over the rear axle, or the garbage can for a muffler that's sitting on the back.

 

my vibrant header downpipe gave me 14whp 14wtq


25whp is not happening

 

zzp upgraded their bolts to 1/2" so no worries if yo got it after 3/22