[goata8]

I was thinking 1 7/8" TSP headers with off road connections and just keeping the stock exhaust from there back, the stock X and non NPP muffler. That way it'll be a little quieter, retain AFM valves... In my extensive searching I think I only came across one guy (oldman I think it was) who ran headers with the non NPP muffler. Trying to get my hands on a oem NPP catback and swapping it out but haven't been able to source one locally for a while now.

I've done the loud exhaust thing on my past couple 4th gens and I'd like to keep it a little quieter this time around (as quiet as headers with no cats is going to be). End goal for the car is just a FBO car thats consistent at the strip and quick. Is there anything I should be concerned about if I go this route? Most guys have the NPP but I'd assume the mid pipes are the same and I shouldn't be leaving too much on the table power wise at bolt on power levels running the stock X and muffler, no?

Any input is appreciated...thanks yall.

[MrRuss]

Headers with no cats and NPP is quite loud and raspy, likely quieter with non-NPP. I have headers, cats all 3" pipes and 3" Stainless Works NPP and it is pretty loud. I get a little self conscious starting it at 5am in my suburban neighborhood but no complaints yet.

Why do you want to keep the AFM? most remove them and tune the V4 mode out. You have to tune for headers anyway.

[6spdhyperblue]

This is what you want in your mid pipe

Originally Posted by Katech_Zach

https://www.summitracing.com/parts/j...4aAsryEALw_wcB

If you want something very similar to the magnaflow, but more of a true "x" insted of a Y-to-y connection internally. Just installed on a customer's ZL1 with ARH headers + Borla Atak (extremely loud). Now the car is very tame and tastefully loud. Jones-MF2469. It had no power loss when doing an a-b comparison compared to the unmuffled exhaust system at 860rwhp.

I will be installing this muffler on my personal ZL1 to try out with my ARH setup + Borla S-Type.

It is more of a factory style "stamped x" rather than an aftermarket "spliced-x" if that makes sense, but still an X and more free flowing than the magnaflow's Y-pipe setup.

We chose to install this in place of the ARH X-pipe that is up front. The packaging on this muffler is a little better than the magnaflow (slightly narrower), so it can be tucked further into the tunnel which is nice.





The body width

[goata8]

AFM can stay or go, I'm really indifferent on that. I just figured it'd sound better in 4cyl mode when keeping AFM active. (could be wrong on that, never had or heard an AFM equipped car with aftermarker exhaust in person. ( Correction: I was unaware AFM could be deleted, facepalm for me)

Another reason I was leaning towards keeping the stock x is not only obviously good fitment.

I'm going to install basically FBO E85 and get it tuned all at once. So it'll get a dyno tune. Ideally I'd like to find a oem NPP exhaust locally and swap over to quad tip, cut that one up for the long tubes allowing me to keep my stock non NPP in one piece in the garage and just reinstall, go back to stock and have the stock tune put back when the time comes to trade her in. Thats my tentative plan. I dont mind doing the off road x, the price really is negligible but if I'm really not leaving much on the table with the stocker (which I may be?) then I won't.

So what do yall vote then? Headers w/ off road x into stock exhaust (non npp, npp is i can get my hands on one)? Like I said, really don't matter either way, I'd like to just do everything all at once, get it tuned and enjoy the car at the strip.

[Baddawg53]

I have a non NPP and an NPP muffler, there's roughly a 7 decibel difference between the two on my car. It is a cammed car, 1 7/8 headers with kooks cats, borla resonators(a must with headers). I much prefer the sound of the NPP, but it's still pretty loud (103.6 db at Sonoma raceway).

[goata8]

Originally Posted by Baddawg53

I have a non NPP and an NPP muffler, there's roughly a 7 decibel difference between the two on my car. It is a cammed car, 1 7/8 headers with kooks cats, borla resonators(a must with headers). I much prefer the sound of the NPP, but it's still pretty loud (103.6 db at Sonoma raceway).

After hearing some youtube clips of non npp w/ headers cars, not a fan of the way it sounds. I think the two mufflers are quite a bit different moreso than just the valve system. So if I can get my hands on a NPP system cheap I think i'll do the swap. If not I'll probably go AWE touring or Borla S type.

I get what yall are saying with the X pipe. Appreciate the input guys.

Again I'm not going for some all out Full bolt on setup. The car's paid off and warranty is up, so I'm looking to have some fun with it. Typical "budget" FBO setup. Also have a truck so I can afford to have some downtime while I'm tinkering with the car.

[red6.2]

hey baddawg53, i have a question for you? sent you pm, thanks.