iMuf

Hey everyone, So not to long ago I got a 2006 Chevy Monte Carlo SS. It is an amazing car and sounds really good with the stock exhaust, but I want more haha. Originally I thought about just swapping out the muffler with a spintech 6000 series muffler which I think has a great sound. But as I think about it, I might as well upgrade the exhaust and get some better performance and possibly better gas mileage. So I had thought about just getting a new downpipe, cat, and jump up to 2.5 inch pipe all the way back and then get some spintechs along with some 4 inch tips. And then I did some research and found out that a lot of people run catless since you get better flow and then when it comes to inspection time, you just unbolt the catless exhaust and bolt up the old exhaust and get the inspection and then swap them back out again. So I have thought about doing that now. Here are my questions, Do you guys recommend doing that? will I get better performance, flow, and sound by going that route, or are the gains not worth the hassle of swapping exhaust over and over? And also, if you go catless will that throw off any engine codes or cause anything like that to happen? When you get a new exhaust will it have spots for O2 sensors, or do you have to fabricate those? and my last question is, do you guys have any recommendations on down pipes, be it catless or not, as well as piping? I think those are all my questions. Thanks guys.

lVloses

iTrader: (1)

Here's what I did. I bought the Dough Thorley Headers. From there I went with a 3" flex coupler directly to a fake cat. Looks very real so if all they do is visual inspections you're good. Next I went with a res delete and 3" back to the Y. From the Y I am running 2.5" to a set of Magnaflows. It gave it quite a boost in volume from the original Magnaflow kit. It also will kill off a decent amount of your low end power. So instead of more MPGs, I would expect less as that's what happened to me. (Not enough backpressure) But it will definitely give you a good SOTP feel when you stomp on it.

Now going catless you will throw a code so you'll have to get it tuned out. Not too hard since you'll want a tune after upgrading your exhaust anyway.

iMuf

Here they do more then just a visual inspection. And after I get the code tuned out, let's say for every inspection I take swap exhaust and put the old one back on for the inspection, after the inspection when I swap exhausts again, would I need to go get the code tuned out again? If so I may just look into getting another cat. It's not a big deal since the 06' only has 1 cat. And then I could just delete the res and go from there.

lVloses

iTrader: (1)

No, once you program out a code, it's gone for good unless you reprogram it back in. What all do they do for inspection there? In my state they don't even have an emissions check so I do pretty well lol. But most states having the code tuned out and having a fake cat is sufficient. Unless they stick the probes up your tailpipe. If you're super concerned you could do something just like this:

https://ls1tech.com/forums/ls4-perfo...tures-lol.html

Just put some flanges in so you can change out the pipes when you have emissions test.

iMuf

This is what all they do http://www.ncdot.gov/dmv/vehicle/reg...on/inspection/

I just turned 20 and have only had 2 inspections done and they were on my older car and I was never the one who took it to get it inspected. But it says they do it through OBD, Not sure if that means I could get away with a fake cat. And on new exhausts, do they have places for O2 sensors, or do they need to be modified?

lVloses

iTrader: (1)

It sounds like all they do is check for a code, so you probably wouldn't even need a fake cat at that. Just a quick tune and you'd be safe. But I'd go ahead and get a fake cat just incase they change the law in a few years or they actually do look under the car. It's only $50 that can save you a ticket down the road.

And if you go 3" all the way you'll have to do it custom. So you can add in a rear O2 sensor if you want to make it look even more legit. An O2 sensor bung is only like $20, or you can probably buy a 3" pipe with an O2 bung already welded in place.

iMuf

I was just thinking about going with 2.5". I don't plan on making my car a hot rod or anything like that. I just want a little more flow and a little more volume and maybe a bit more power. I have heard if you go with pipe that is to big it can hinder performance if you aren't running things like turbos and all kinds of other stuff. So if I went with 2.5" would I be in the same situation where I would need to get an O2 bung welded in or do you know of any that come with it already? I appreciate the help by the way

lVloses

iTrader: (1)

The only thing bigger piping will do is hurt your low end. Your top end will love the bigger pipes. But if you want 2.5" you can do a few different things. Magnaflow sells a kit that's 2.5" from the cat back. Then you can get a ZZP 2.5" downpipe to get rid of the cat and u-bend.

Or ZZP also sells a 2.5" catback exhaust that should fit without much hassle. You just need to move an exhaust hanger is what I've been told. The thing with the ZZP exhaust kit though is it necks down to 2.25" at the Y. They also make this in 3" down to 2.25" at the Y.

Third option you can get the DT Headers and go the route I did. You won't lose a whole lot of MPGs. You may even gain some after getting a tune. If you're getting rid of the resonator I'd disable DoD through a tune though. Otherwise the sound will get annoying fairly quickly.

How much are you looking to spend, do you know?

iMuf

Honestly as much as I need to spend to get what needs to be done, haha. I have one job that pays for the car payment and what not and then I work with my dad and make really good money on the side, so money really isn't a big deal. originally I thought about going with something like a magnaflow cat back but then from the reviews I have read, for the amount of money you pay, you don't get a huge increase in volume. I'm not looking for something annoyingly loud but I do want a deeper tone and a little more volume. I'm just trying to find out the best way to go about doing it. This is only my second car and the first one that I really want to do things to and make better, be it looks, or performace.

lVloses

iTrader: (1)

If money isn't an option I would do it once and do it right. Get a set of DT headers. ($700) ten do a custom 3" catback exhaust (cost me roughly $800 for 304 SS). Then have it go into whatever mufflers you want with tips ($200+)

I originally spent $700 on the magnaflow kit and ripped basically all of it out excluding mufflers and tips lol. You'll be looking at $2k for a good exhaust that will last the life of your car, or $1.5k if you'd rather go with alumnized steel. I spent easily $2.2k on my exhaust setup :/

iMuf

alright, where did you get your piping at?

lVloses

iTrader: (1)

I bought mine through here since my exhaust guy couldn't bend bigger than 2.5". I bought way more pipe than I ever needed lol. But you can get everything you need there. Up here the roads are nice and salty and lots of snow come winter time so it's a must have for 304 SS.

http://www.mandrel-bends.com

blkchevyz

wow
you should be able to get some SS piping from here for way cheaper than that
http://www.mandrel-bends.com

i wouldnt think it would cost much more than a 100-200


i replaced just the back half of the exhaust did it with a single in dual out muffler, then a couple bends to exit it out the stock location. cost about 75 with the muffler (granted i used some exhuast tips i already had) lol
i'm going to redo it from the cat back with 3 inch. what i'm figuing i need is 1 3 inch u bend, 2 2.5 inch u bends and some strait 3 inch pipe.

91parkave

iTrader: (4)

Who really cares about low end tourqe on a fwd v8 I have a custom 3' as well still have more than enough tourqe to fry tires. my 3' system cost me under. 300 bucks I ordered mandrel bends and a really big long cherry bomb in 3' coated all piping in high temp paint and have no rust even through monsoon season. While ss is always better I opted for standard steel piping. Good luck on your exhaust

lVloses

iTrader: (1)

Mine included installation, fake cat, coupler, and multiple bends. I also did buy much more than I needed. It can be done cheaper if you're able to do it yourself or your exhaust shop can bend piping that big. And of course you'll save money if you get 409 SS or aluminized.

91parkave

iTrader: (4)

OK man what the hell did the shop need to bend if you ordered all mandrel bends? That's a cut and weld affair and if they bent it that means crush bent which can almost cut the pipe diameter in half

smoooth

I'm the odd man out here.....I want my car quieter. I'm sure after putting the DT headers and catless 3" down pipe in it will get louder, so looking to quiet it down. I've thought about changing the resonator out for a glass pack to see if it helps. At least it's a cheap try. I'm putting in an electric cutout for when I wan the flow and noise.

Most people around here didn't know GM ever put a v8 in these cars so I'm thinking if I can keep it as quiet as I can, I should be able to drum up more races....then flip the switch, let it rumble, and watch their faces as they wonder WTH!

Cory1750

This is the funniest thing. Everyone thinks these cars are V6's. Everyone seems really frustrated when they can't get away from it.

lVloses

iTrader: (1)

I'm saying they can't bend that so I had to buy all the bends. Which are like $30 a piece. Plus straight pipe and all the other stuff put me to roughly $400 I believe. Then since shops can't legally install catless exhaust, I had to pay a bit extra on top of labor.

gilroy222

I think another guy posted this somewhere on here but has anybody ever bought this and had a shop install it? I looked through all the piping on ebay and it seems once everythings all said and done you can just get this already made into a kit.

http://www.mandrelexhaustsystems.com...ND-PRIX/Detail