Well I went to the dyno today after after my runs they noticed my power was a little low and started looking for a reason. They came to the conclusion that my cats were clogged and my system was too small (2.25"). When I bought the car the exhaust was already on it, so some dumb person before me actually put a smaller exhaust system on the car My question is can i just get a custom built y-pipe from a muffler shop or would it be better to just buy one and have them install it? Also which size, they told me 2.5, but wouldn't 3" be better? Any suggestions would be helpful, because now I know where my money is about to be spent for the summer.

 

You talking the Y-pipe or the I-pipe??? The stock y-pipe is 2.25 ... AM y-pipes are typically 2.5 and really not worth it, unless you intend to remove the cats also ...

Good Luck

 

Well if the exhausts Intermediate pipe is 2.25" then yes some fool put a lame small system on the car. BUT if your talking about the "Y" being 2.25" thats stock size normal for passenger side and driverside is crushed oval like.
Some say too small,others like T racing say it flows just fine for light modded cars. Ehh whatever I want to get a 3" but a 2.5" would get ya more flow then now. But they said it was your Cats so if I were you maybe a RT Y pipe w/ high flows.Maybe Bassani.
Why dont you tell us what the dyno #'s are? Come on

 

i thik hes talking about y pipe......its fine

 

cutout closed: 285.4 hp 311.2 torque
cutout open: 300.6 hp 317.2 torque
and yes, the whole freaking system is 2.25", the only part that isn't is the 3" cutout i bought, so yes, flow is very restricted.

 

ehh... i've seen stock dyno #'s for an o1 ss a4 run better...

 

What are your mods, just the cutout? But yeah, that seems low. With a lid/muffler I put down 291, and yours should be higher on the plain fact of it being a 01 with the LS6 intake and whatnot. But yeah, get hi-flo cats or get an ORYpipe (depending on emissions) Cats can be very restrictive.

Nate

Ps I'm still pissed that everyone's getting 20 more tq than me

 

I have a Z06 MAF, lid, and the cutout. they were estimating around 330 before i made my runs. Last night running it around town I noticed that when i got back the rotten egg smell they were talking about. I used to think that it was just the burnt fuel in the exhaust, but know that i know it is the cats that are clogged i notice that smell all the time. Can a mufffler shop do a fully custom exhaust? and can they do mandrel bends?

 

Oh yeah, and talk about terrible, before we opened the cutout, it dynoed at 285.4 rwhp and 311.2 torque, so you know something is wrong with those low numbers...

 

I don't believe a Y-pie will help you much, if at all. I would say the first thing you should do is replace those cats then add a cat-back.