[Z OH 6]

Originally Posted by JSH

I do not need NPP.

Each of us have a different idea of how our car should be configured. I'm now thinking something like this pic - straight-thru - behind my headers/hi flows

The touring exhaust is straight through too, just uses their 180 degree mufflers to control the sound, I strongly recommend you use the touring exhaust if you have headers and high flow cats. The track exhaust would be unbearably loud.

[Camaro1973]

Originally Posted by JSH

I do not need NPP.

Each of us have a different idea of how our car should be configured. I'm now thinking something like this pic - straight-thru - behind my headers/hi flows

This setup will wake the dead.

[JSH]

Originally Posted by Camaro1973

This setup will wake the dead.

OK, you guys convinced me. What about this Touring cat back, but I wonder if it comes with less of a muffler?

[Z OH 6]

Originally Posted by JSH

OK, you guys convinced me. What about this Touring cat back, but I wonder if it comes with less of a muffler?

Catback is the same mufflers as the axle back, with the catback you're paying for 3" mandrel bent pipe from the cats back. You can also go with the resonated touring exhaust which adds resonators right after the cats to help take some edge off. I strongly recommend the resonated touring catback if you decide to go with a catback. Otherwise go with the touring axle back.

[Chutzpah]

Originally Posted by Z OH 6

Not to hate anyone with the Borla exhaust but the tips look awful to me, they stick out too far, the Borla logo is bright white, and there's screws all the way around the tips. The AWE diamond black (black chrome) tips just look so much better and they're 4.5" instead of other aftermarket exhaust that uses 4" tips. The ONLY downside to the AWE exhaust is that there are no NPP valves if you need them.

I agree with everything you’ve said about the Borla tips. I know the they can be pushed back bit, but still don’t like the shape, screws, or the heavy Borla embossing.

As has been noted, to each their own...

[jaybee924]

Originally Posted by Z OH 6

Catback is the same mufflers as the axle back, with the catback you're paying for 3" mandrel bent pipe from the cats back. You can also go with the resonated touring exhaust which adds resonators right after the cats to help take some edge off. I strongly recommend the resonated touring catback if you decide to go with a catback. Otherwise go with the touring axle back.

I may down the line do cat deletes like after my warranty go off on my New ZL1. Do you think the AWE touring will still be way too loud? I leave out about about 5:45a but it's not my daily and stays at another place but if it's nice out I may drive it a couple of days a week just have to go pick it up. I'm looking hard at the Borla Atak NPP especially if I need up doing that later. Looking years down the line. What do you think?

[Z OH 6]

Originally Posted by jaybee924

I may down the line do cat deletes like after my warranty go off on my New ZL1. Do you think the AWE touring will still be way too loud? I leave out about about 5:45a but it's not my daily and stays at another place but if it's nice out I may drive it a couple of days a week just have to go pick it up. I'm looking hard at the Borla Atak NPP especially if I need up doing that later. Looking years down the line. What do you think?

If you remove the front cats, its going to be loud, period. The stock NPP will help some in stealth mode but its still going to be much louder than it is with the stock front cats.

[KingLT1]

I have had the Flowmaster NPP for a couple seasons now. I like it other then I do get some drone with the valves open but I do have cat deletes. The valves being closed is significantly quieter then open. I do think the exhaust would be about perfect with cats. So for that reason I have the Corsa NPP on order. CSP had a good sale on it over the Holidays so I decided to try it. Probably just wasting money at this point but I had a few Holiday bucks to spend. Take note you don't gain power from any exhaust mod post cats, so you are essentially spending a grand or two for looks and sound. I definitely wouldn't want to give up the NPP function if you have LT headers and/or cat delete's. These cars get stupid loud and having the ability to quiet the exhaust note is Nice when you just want to cruise around and not make a bunch of noise. Really loud exhaust gets old after a while imo.

[JSH]

When you say cat deletes, do you mean hi-flow cats or no cats?

Regarding hp, it's my understanding that the stock cat back has a crimp in each pipe at the axle. If this crimp is significant enough to cause any back pressure, then it theoretically reduces hp since this engine should perform best with a scavenging effect or negative pressure at the exhaust valve/port. If said crimp does not cause ANY back pressure then an axle back system would be sufficient for me.

Originally Posted by KingLT1

I have had the Flowmaster NPP for a couple seasons now. I like it other then I do get some drone with the valves open but I do have cat deletes. The valves being closed is significantly quieter then open. I do think the exhaust would be about perfect with cats. So for that reason I have the Corsa NPP on order. CSP had a good sale on it over the Holidays so I decided to try it. Probably just wasting money at this point but I had a few Holiday bucks to spend. Take note you don't gain power from any exhaust mod post cats, so you are essentially spending a grand or two for looks and sound. I definitely wouldn't want to give up the NPP function if you have LT headers and/or cat delete's. These cars get stupid loud and having the ability to quiet the exhaust note is Nice when you just want to cruise around and not make a bunch of noise. Really loud exhaust gets old after a while imo.

[KingLT1]

Originally Posted by JSH

When you say cat deletes, do you mean hi-flow cats or no cats?

Regarding hp, it's my understanding that the stock cat back has a crimp in each pipe at the axle. If this crimp is significant enough to cause any back pressure, then it theoretically reduces hp since this engine should perform best with a scavenging effect or negative pressure at the exhaust valve/port. If said crimp does not cause ANY back pressure then an axle back system would be sufficient for me.

Cat delete means exactly that...the Cat's are deleted. I have the CA bolt-in delete pipes. I didn't go headers because of the added noise and for reasons I'll explain below.

Far as the crimp section...It's been proven that the NPP cat back is not restrictive until you get north of 800whp. CSP did a dyno comparison when he had his H/C ZL1 and gained like 3-4whp.

The exhaust mods that gain power are deleting the primary cats(biggest bottle neck), then headers. Headers with high flow cat's are marginally better then factory headers with cat deletes. Catless 2" headers are worth about 20whp over stock headers with cat delete's on a 7-750whp car. I am sure the gains become greater the closer you get to that 1k whp mark.

[JSH]

So the crimp does NOT reduce hp which makes the case for me for an axle back system, with the caveat that I'll add another 50hp soon, which will get me near 800 wheel

Originally Posted by KingLT1

Cat delete means exactly that...the Cat's are deleted. I have the CA bolt-in delete pipes. I didn't go headers because of the added noise and for reasons I'll explain below.

Far as the crimp section...It's been proven that the NPP cat back is not restrictive until you get north of 800whp. CSP did a dyno comparison when he had his H/C ZL1 and gained like 3-4whp.

The exhaust mods that gain power are deleting the primary cats(biggest bottle neck), then headers. Headers with high flow cat's are marginally better then factory headers with cat deletes. Catless 2" headers are worth about 20whp over stock headers with cat delete's on a 7-750whp car. I am sure the gains become greater the closer you get to that 1k whp mark.

[Z OH 6]

Originally Posted by JSH

So the crimp does NOT reduce hp which makes the case for me for an axle back system

At some point, I'm sure it does cause some restriction but I don't know what that HP level is.

[dmcmahan60]

I have the AWE axel back on my car. It was a non npp single dual tip not the quad tip setup. little rowdy on cold starts but other than that it has zero drone and sounds great. Quiet at highway speeds but mash that happy pedal and she comes alive

[JSH]

Originally Posted by EvilZL

I have the Borla S-Type Axle Back NPP with the Carbon Fiber Tips! just to get me by until I do headers and off road connection pipe, with a few bolt on's!
The carbon fiber tips look bad ass and the s-type sounds great

I don't see an axle-back system for my car at their site (?)