[NICKEL1810]

I want to get feedback from people that have an axle back or cat back exhaust with headers and no cats. That is my set up on my car with stock npp. I want to see what kind of exhaust you are running and possible sound clips. Also your opinion whether it’s truly that much better than stock. I made a post a while back and had a bunch of replies to exhaust options. It seems that the majority of people had cats and normal headers. The sound is so different once you add headers and no cats. Just looking for some specific feedback. Thanks.

[Checkmate1]

I hear CSP Headers are excellent considering they don't suffer the install issues of headers like Kooks, TSP etc. CSP is also decently priced.

The issue with Cats is that once you lean out the tune and add more power, most Cats are unable to handle it. There are documented issues of Cats failing which doesn't help. There are some Cats in the market that can handle a reasonable amount of added power. Your local performance shop and/or tuner can advise on the best Cats.

Our cars run rich to preserve the factory Cats.

Once you start installing free flowing headers and starting leaning the tune, things get 'interesting'.

This is why you see a lot of folks running Catless. You just have to live with the smell.

My favorite set up is Long Tube Headers + Xpipe paired to the stock muffler box. You still retain the NPP functionality.

[headgamez]

Originally Posted by Checkmate1

I hear CSP Headers are excellent considering they don't suffer the install issues of headers like Kooks, TSP etc. CSP is also decently priced.

The issue with Cats is that once you lean out the tune and add more power, most Cats are unable to handle it. There are documented issues of Cats failing which doesn't help. There are some Cats in the market that can handle a reasonable amount of added power. Your local performance shop and/or tuner can advise on the best Cats.

Our cars run rich to preserve the factory Cats.

Once you start installing free flowing headers and starting leaning the tune, things get 'interesting'.

This is why you see a lot of folks running Catless. You just have to live with the smell.

My favorite set up is Long Tube Headers + Xpipe paired to the stock muffler box. You still retain the NPP functionality.

Not meaning to hijack, but i am thinking of purchasing the CSP headers. What do you think of the quality in person??

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[Markoz28]

I’m running 2” kooks with no cats, connected to the stock NPP. I think an after market exhaust will be too loud at this point. If I were to change to anything it’ll be Corsa exhaust. It’ll just be too loud for me. I also have a cam so that doesn’t help with volume but it does sound good.

[SJFGTO]

I have LTs, no cats and an ARH full exhaust system. A nice feature of this system is that there is zero rasp. Rasp (that metallic rough rattle) is very common in LT/catless set ups. It does have some drone at highway speeds, but it is of the lower bass variety and not intrusive to my ears. Anywho, beware of rasp with many catless systems.

[Juiced1]

We do long tubes/off road pipes on these cars constantly. All of our packages are based around this. Personally I love the sound. I think it's loud enough for most but not over the top. When you pair it up with aftermarket exhaust set ups it can be a little over the top. Just depends on what you call loud.


We run a lot of Texas Speed 2" headers. They fit pretty good but you have to watch a couple spots that might contact the steering shaft and frame (most 2" headers are like this)


Our favorite option would be the Stainless Works set up. It replaces all the factory exhaust all the way back to the mufflers. Every car we do with these dynos just a bit better (there are some spots were the factory system is crimped)

[rdrfronty]

I have 2" Kooks headers with no cats going through 3" AWE Touring system.
I do have 2ea 12" resonators in place where cats would normally go AND I have I think 2ea 18" resonators placed at the same location that AWE normally locates their resonated system.
Note that I had only the 2 tiny 12" resonators at 1st and it was really two loud & raspy for me like that. Adding the 2nd set of 18" resonators really helped tone it down a lot.
With my current setup I think it has a nice moderate sound at idle, putting around, & cruising. It had no drone at all. But it's nice & loud loud when you really get on it. It also has a very aggressive sound during moderate acceleration. MUCH meaner sounding the the stock NPP setup.
It's about perfect now to me.

[Redlinez]

Heck, I thought my 17 was fairly raspy with the TS 2" catted LT's with X and OEM NPP exhaust. Didn't realize the cats could cause an issue. Smelling like fuel sucked in my cammed LS1's and they were catted.

[NICKEL1810]

Originally Posted by SJFGTO

I have LTs, no cats and an ARH full exhaust system. A nice feature of this system is that there is zero rasp. Rasp (that metallic rough rattle) is very common in LT/catless set ups. It does have some drone at highway speeds, but it is of the lower bass variety and not intrusive to my ears. Anywho, beware of rasp with many catless systems.

Do you have any videos of this setup? Thanks

[DFW_Muscle]

Originally Posted by rdrfronty

I have 2" Kooks headers with no cats going through 3" AWE Touring system.
I do have 2ea 12" resonators in place where cats would normally go AND I have I think 2ea 18" resonators placed at the same location that AWE normally locates their resonated system.
Note that I had only the 2 tiny 12" resonators at 1st and it was really two loud & raspy for me like that. Adding the 2nd set of 18" resonators really helped tone it down a lot.
With my current setup I think it has a nice moderate sound at idle, putting around, & cruising. It had no drone at all. But it's nice & loud loud when you really get on it. It also has a very aggressive sound during moderate acceleration. MUCH meaner sounding the the stock NPP setup.
It's about perfect now to me.

I had 1 7/8" Kooks, no cats, and AWE resonated touring system. I've since pulled off the AWE mufflers and added the stock NPP muffler back on. It was so loud at startup and >30% throttle before, that I couldn't drive it.

However, I no longer get any of the crackles, and it sounds really muted / blatty under load. I am wondering if I were to go with the 4 resonators as you have done, if that would be the happy medium I am after...

Where are you located in TX out of curiosity? I am in McKinney.

[rdrfronty]

Originally Posted by DFW_Muscle

I had 1 7/8" Kooks, no cats, and AWE resonated touring system. I've since pulled off the AWE mufflers and added the stock NPP muffler back on. It was so loud at startup and >30% throttle before, that I couldn't drive it.

However, I no longer get any of the crackles, and it sounds really muted / blatty under load. I am wondering if I were to go with the 4 resonators as you have done, if that would be the happy medium I am after...

Where are you located in TX out of curiosity? I am in McKinney.

I'm just north of Houston in Tomball.
The two additional resonators did make a very big difference. They were 4" x 24" (18" body) Flowmaster resonators.
Before them it was way too loud & raspy. The little 12" (8" body) resonators I had mostly to help with state inspections. I knew they wouldn't do much for sound. I only had the car running & tuned for 1 day before I said no - I had to kill the overbearing sound some. So had a local shop add those two additional ones. I was SO much happier with the sound like that. To be honest, it does still get pretty dang loud under heavy throttle. But I'm ok with that. I MUCH prefer that vs the way too quite factory setup before headers & etc.
I was very disappointed how quite the stock system in the Gen 6. That lasted about 3 months before I had the mufflers cut off & 2 tiny Magnaflows put in it's place. That was ok in sound, but did have a lot of drone.
Now the AWE system with my resonators sounds much better than either setup I had and has no drone.

[JasonSB]

I have TSP headers with resonators behind the stock suitcase and 4 inch black tips. Sounds great. Without the resonators it was very raspy and sounded like crap.

[jvandy50]

Originally Posted by headgamez

Not meaning to hijack, but i am thinking of purchasing the CSP headers. What do you think of the quality in person??

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In the video i saw of them, he mentioned stainless works makes them. I have their catback, and have had multiple pieces from SW on mustangs and they’re nice pieces for sure.

Will likely pair the CSP headers to my NPP SW catback when I’m ready to tune.

[Bosun68]

I bought the 1 7/8” ARH long system (catless) that will tie into the stock suitcase. I hope that it sounds good enough so don’t have to resort to changing out the suitcase and/or adding resonators.