[lennyk1313]

So I did some research but still have questions and looking for recommendations.

So what is my mission and some of my requirements. I am looking to combine the performance with the sound factor. Not necessarily looking for anything that will bee too loud. Two main requirements:

1. I want to keep the dual mode feature.
2. I want it to be a bolt on. I do not want to weld anything.

I still do not know if I want to just get the headers, headers with mid pipes, or a complete exhaust (headers, mid, and axle back). I am open to different suggestions and options. All the input and recommendations are greatly appreciated.

[Ryephile]

If you do headers, that means you need a tune, and thus warranty bye-bye. Does that matter to you?

Since you said a performance gain is part of the decision, then it's long-tube headers (e.g. Kooks 2" w/high-flow cats) with a tune, and keep the NPP. That setup will increase the sound volume a bit, but not a crazy amount. There's no noteworthy gain by changing the cat-back, other than sound & loudness. Right there it kind of pigeonholes the situation if you're serious about adding power.

[lennyk1313]

Originally Posted by Ryephile

If you do headers, that means you need a tune, and thus warranty bye-bye. Does that matter to you?

Since you said a performance gain is part of the decision, then it's long-tube headers (e.g. Kooks 2" w/high-flow cats) with a tune, and keep the NPP. That setup will increase the sound volume a bit, but not a crazy amount. There's no noteworthy gain by changing the cat-back, other than sound & loudness. Right there it kind of pigeonholes the situation if you're serious about adding power.

That's good info. I don't mind doing headers and tune. Most of my cars were tuned in metter of months after purchase . But to follow up with couple more questions.

Kooks have several options:

2" x 3" Headers (GREEN CATTED)
1 7/8" x 3" (CATTED)
1 7/8" x 3" (GREEN CATTED)

Is there a big difference between the 2" vs. 1 7/8? I heard that you don't really need 2" unless you are pushing past 700HP? And finally, is there a big advantage to the Green Cats for extra $500?

[Zvelts]

I am also interested in this kind of set-up, performance and i little more volume.
How is the sound with catted long tube headers and stock cat back and NPP ?

I dont know if catted LTH and Street MBRP Axel back would be very loud ? I would like something a little deeper than stock. The MBRP cat back Must be a nice weight saving also.

[chozn4service]

I have the NPP Dual Mode and wanted to keep it since it came with the car. I wanted louder but not obnoxious. I also don't want to void the warranty at this point so my options were limited but I had to go with what I know and that was with Flowmaster American Thunder. I did an axle back which really sounds great and then I added the Scavenger X pipe by Flowmaster and if sounds even better and deeper. This whole deal is so subjective in that everyone has their own particular wants in sound and ideas of what sounds good to them.
For me, I'm 60yrs old and I'm use to the old school muscle car sound and have found that only Flowmaster gives me that sound that I seek. Seems like the others like Borla, Corsa and some of the others seem to give cars more of an exotic sound vs a muscle car sound.

I'm really happy with my program and you can do searches on YouTube and listen to various samples, just have on headphones to get a better feel for them.

Good luck with the program....

[lennyk1313]

Originally Posted by chozn4service

I have the NPP Dual Mode and wanted to keep it since it came with the car. I wanted louder but not obnoxious. I also don't want to void the warranty at this point so my options were limited but I had to go with what I know and that was with Flowmaster American Thunder. I did an axle back which really sounds great and then I added the Scavenger X pipe by Flowmaster and if sounds even better and deeper. This whole deal is so subjective in that everyone has their own particular wants in sound and ideas of what sounds good to them.
For me, I'm 60yrs old and I'm use to the old school muscle car sound and have found that only Flowmaster gives me that sound that I seek. Seems like the others like Borla, Corsa and some of the others seem to give cars more of an exotic sound vs a muscle car sound.

I'm really happy with my program and you can do searches on YouTube and listen to various samples, just have on headphones to get a better feel for them.

Good luck with the program....

Thanks for the input.

[MAGAUSA]

What I'm about to suggest will violate your not wanting to weld. However, if you do anything other than a full cat back you're likely going to weld. Try this in stages, try the Borla mid pipe, deletes the the 2nd cats, changes the x pipe, welds to the stock suitcase. It's a relative cheap way to change the sound. You could then do LT headers, mate up to the mid pipe. Once there you may not see any need for a 1200+ cat back with valves.

[lennyk1313]

Originally Posted by MAGAUSA

What I'm about to suggest will violate your not wanting to weld. However, if you do anything other than a full cat back you're likely going to weld. Try this in stages, try the Borla mid pipe, deletes the the 2nd cats, changes the x pipe, welds to the stock suitcase. It's a relative cheap way to change the sound. You could then do LT headers, mate up to the mid pipe. Once there you may not see any need for a 1200+ cat back with valves.

Hmm another option to think about. What about something like ARH 1 7/8" Long System with cats or ARH Intermediate System. They say no welding required and I can reuse my stock mufflers (or mufflers with mid pipe and secondary cats if used with intermediate system)?

[chozn4service]

I don't think the OP wants to void warranty at this time and headers will do just that as they require a tune. The footlocker in the back is an eyesore and I had to get rid of that, plus there is a savings of weight with it's ditching. The axle back is a great way of doing stages, then if not satisfied going with the mid section as I did which deleted the secondary cats. All this is bold on as you go.

[Ryephile]

Originally Posted by lennyk1313

That's good info. I don't mind doing headers and tune. Most of my cars were tuned in metter of months after purchase . But to follow up with couple more questions.

Kooks have several options:

2" x 3" Headers (GREEN CATTED)
1 7/8" x 3" (CATTED)
1 7/8" x 3" (GREEN CATTED)

Is there a big difference between the 2" vs. 1 7/8? I heard that you don't really need 2" unless you are pushing past 700HP? And finally, is there a big advantage to the Green Cats for extra $500?

The "Green" cats should be used in states where you have an annual sniffer test at an inspection station. The high-flow cats *might* pass a sniffer, but if your state doesn't use a sniffer test, then by all means they're a solid choice while still being a responsible adult.

Forum sponsor PRAY is a long-time GM tuner and found the Kooks 2" headers to be all-win over the 1 7/8" headers, even with bolt-on n/a setups. He has back-to-back dyno plots in one of his threads to prove it.

Hope that helps.

[umby24]

I just installed the stainlessworks catback system last weekend. It meets all of your requirements. No welding, keep warranty, keep NPP functionality.

The system is quite a bit louder than stock, and has a nice deep tone to it. (Hard to hear the deep tone and the volume over a video, but if you're interested let me know)

[lennyk1313]

Thanks for all the input guys. Lots of options and a lot to think about.

[JBones81]

I just had the Hurst Axle back installed. Keeps the dual mode option. The car sounds much better, but it really isn't that loud at all.

[MAGAUSA]

Originally Posted by umby24

I just installed the stainlessworks catback system last weekend. It meets all of your requirements. No welding, keep warranty, keep NPP functionality.

The system is quite a bit louder than stock, and has a nice deep tone to it. (Hard to hear the deep tone and the volume over a video, but if you're interested let me know)

Yes! videos please!