[chargerjake]

I bought my first Camaro (yay!) last week, of course with help from my parents cause I don't have a higher paying job. It was a 2LT RS, pretty much loaded except for the NPP exhaust. I really like it so far.

Since it was a stretch for my family and I wasn't able to put that much down from my summer job, they're reluctant to let me do any engine/exhaust mods (which is understandable) but I might be able to convince them to let me remove the secondary cats. I'm trying to get a throatier sound out of the car, similar to what the NPP sounds like when the valves are open. So, what does deleting the secondary cats actually do if I decide to leave the stock muffler on the car? If anyone has any videos of their V6 Camaro with removed secondary cats and stock mufflers, that would be cool too. Just trying to gauge what it would sound like and whether or not it'd be worth it to try and convince them.

Thanks!

[Dustya]

if you are leaving the entire exhaust stock deleting the secondary cats is not doing much for you at all.

[PolynesianPowerhouse]

Originally Posted by Dustya

if you are leaving the entire exhaust stock deleting the secondary cats is not doing much for you at all.

Bingo.. most are doing it for a minor sound increase. Bit on ost cars, theres not really a performance gain.

Its like the bent pies under the axles. Somehow the design doesnt hamper flow in stock form.

Now an extensively modfied car... may be an advantage.

The rear muffler is prob the most restrictive piece.

Id advise agains hacking up your exhaist unless you know specifically what your trying to do or accomplish. Most end up making theor car sound crappy and lose performance just hacking off pieces

[hightorq]

Yeah learn from my fail I hacked mine out and did a fuse pull car does sound good but I will need to do a replacement if I ever sell my car.

[Glen e]

My whole thread with pictures of the install is here somewhere. Search under my name. It will make some difference, but not a lot. I deleted them on top of adding the GM performance axle back (borla) and it made a difference,but not sure it would make any difference if I was still using the stock suitcase muffler. Important: find somebody who can weld and make sure that the total job is airtight. Otherwise you'll get a CEL.

[CamaroCasper]

Good info here ���� I'm wondering the same thing. Basically wondering if it would make a sound difference if I keep the NPP suitcase muffler on for now. Eventually wanna upgrade to Borla or some sort of other axle back, but for now just wanted a change in tone. Although the more I drive the more the NPP just sounds great for now. Idk, if it's worth it. But still a thought on my mind.

[hightorq]

Do a fuse pull first and see if that is enough noise. The delete adds some snarl up top but did not to any favors for the low tones of the car.

[SamMoranPranks]

Originally Posted by hightorq

Do a fuse pull first and see if that is enough noise. The delete adds some snarl up top but did not to any favors for the low tones of the car.

He cant do the fuse pull on a 17. He'll risk getting a CEL if he does. GM reprogrammed the computer on the 17's to look out for that fuse pull and it could cause issues. The 16's are good.

I'll tell you this, like most people have said the secondary cat delete will give you just a little more sound. Nothing crazy, nothing completely noticeable. If that's what you're looking for, go for it. But if you're looking for something that will be more noticeable, you might wanna try a different route. I've messed with all types of exhausts on my 16 RS, so I know what does and doesn't sound good through experience haha.

Also, be careful with Borla. They're a great manufacture, but the sound change isn't all that drastic when you go with their axlebacks. In my opinion, they are a waste of hundreds of dollars when you can get a custom exhaust for cheaper and much better sounding.

[_MerF_]

I just (yesteeday) had a muffler shop delete the suitcase muffler for me. Got ir done for $130 out the door. Can hear the LGX now (no more "they made an electric/hybrid Camaro?" jokes) and although I am still adjusting to actually hearing the exhaust now under acceleration, it doesnt drone at all at cruising speeds.

I have no delusions that I picked up any noticable performamce gains, this was purely for the sound factor, but I couldn't be happier for the price. Just giving you something to consider.

[Reximus]

Originally Posted by _MerF_

I just (yesteeday) had a muffler shop delete the suitcase muffler for me. Got ir done for $130 out the door. Can hear the LGX now (no more "they made an electric/hybrid Camaro?" jokes) and although I am still adjusting to actually hearing the exhaust now under acceleration, it doesnt drone at all at cruising speeds.

I have no delusions that I picked up any noticable performamce gains, this was purely for the sound factor, but I couldn't be happier for the price. Just giving you something to consider.

Stock isnt completely terrible, if anything the 4cyl sounds more like a hybrid stock.

[PolynesianPowerhouse]

Ill say with borla, from experience. the sound change is huge. That is if you drive the car like its supposed to be driven. Lets be realistic, some here are daily drives or weekend cruise to cars and coffee only types. revving cars in park is really popular in youtube videos, but unless there is a load on the engine...you are NOT going to hear the full sound of a car. factor that in with some people have lower end cell phones, or even some good ones... but they don't have HD mics... same goes for the speakers you listen on. I honestly have not seen one axleback from borla in person ( i run the s-type) that wasnt a huge difference in comparison to stock. Even the gm branded touring version.

With that being said, the only mod that i did with back to back track days was the axleback exhaust, and both mph were higher, as well as my times dropped from a consistent 14.1 to 13.5s all day. any axleback will flow better than stock. its straight through, and no multiple chambers for the exhaust to expand and slow down.

If anyone is removing the rear muffler, and throwing it away....do yourself a favor, cut it open. when exhaust flows through it, there's HUGE chambers inside.

This is the NPP Version. if the valve is NOT open, it comes in, goes through the perforated area, goes to the tail end, flows into the opening and then out the inner pipe once it comes from the separate chamber.

on the regular exhaust, it basically comes in, flows to the bottom in the huge open area, then into the opening to another chamber, then out the rear.


its simple logic.... gases, like lava, flow fast when inside of a tube... once it gets to an open area, it cools off, slows down, and theres your performance losses. switch to something straight through if you want performance.


However, this is how you mass produce a muffler that takes out 75% or more of the sound that it normally would make. theres older people, men and women that by the car for looks. not a care in the world about how it performs. its nostalgia meets modern. so for the masses, that's what any production company caters to...not the few performance freaks like some of us.


there's 2 types of mufflers. those that absorb sound or those that cancel sound by reflection, or losing velocity (velocity is what's needed to have a good flowing exhaust...not backpressure and the internet myth still looms)





also to keep in thought 2 things:

1) Theres a difference in hacking up an exhaust to get more noise... vs adding an exhaust to get a more refined sound from it.
2) The way you car sounds when you are in it is def different from what it sounds like when everyone else hears it drive by. that's why a lot of sport compact car drivers think their car is amazing sounding, cause inside, you hear more the bass...outside, you hear the rasp and higher pitched unwanted tones.



Just something to keep in mind.

[Lukemo]

Originally Posted by SamMoranPranks

He cant do the fuse pull on a 17. He'll risk getting a CEL if he does. GM reprogrammed the computer on the 17's to look out for that fuse pull and it could cause issues. The 16's are good.

I pulled the fuse on mine and have never had any problems; been driving it like that for over a year now.

[pjz1082]

What fuse do you pull? I realize I could do a search but if someone can just tell me, that would be terrific

[Lukemo]

Originally Posted by pjz1082

What fuse do you pull? I realize I could do a search but if someone can just tell me, that would be terrific

F51