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So I'm thinking of having headers installed and have some basic questions. I did get some good information from a search of the forum and the net but wanted some more info.
1. It appears that LT headers work well with the stock NPP mufflers, anyone have experience with this set up?
2. Anyone know of any reputable shops in the DC metro area that people have experience with? I could include PA, DE, and surrounding states as well.
3. What can I expect to pay for these installed? I was looking at Kooks in particular.
I appreciate any thoughts on this. I was between this and a cam but would rather just do the easier bolt ons at this time.
Thanks!
My 2011 GS / A6 had the NPP mufflers. Obviously the car was a little loud at full throttle when the NPP valves would be open, but still sounded good.
Then I installed a set of headers with cats ... The car really was not much louder at all during idle and normal driving, but at wide open throttle, the exhaust sound became obnoxiously loud.
The only fix was to remove the NPP mufflers and replace them with a set of Borla 'Touring' mufflers.
Now the sound is just slightly louder during normal cruise than it was with the NPP mufflers (when the NPP valves are closed) ... but much quieter at wide open throttle (still sounds really nice, but not horribly loud like it was with the NPP with headers).
Just my opinion ...
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My 2011 GS / A6 had the NPP mufflers. Obviously the car was a little loud at full throttle when the NPP valves would be open, but still sounded good.
Then I installed a set of headers with cats ... The car really was not much louder at all during idle and normal driving, but at wide open throttle, the exhaust sound became obnoxiously loud.
The only fix was to remove the NPP mufflers and replace them with a set of Borla 'Touring' mufflers.
Now the sound is just slightly louder during normal cruise than it was with the NPP mufflers (when the NPP valves are closed) ... but much quieter at wide open throttle (still sounds really nice, but not horribly loud like it was with the NPP with headers).
Just my opinion ...
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Older, Type 1 Borla 'Touring:
Thanks for the info. Definitely something to consider. I suppose there is no harm in doing the install and deciding if I want to add new mufflers after I play around with it.
i installed kooks long tubes with the x pipe and 3" race cats, i have the factory NPP exhaust, it's LOUD under WOT. there is only one reason why i kept the NPP with a flip of a switch it's quiet.. there is some drone with the factory NPP. i just installed kooks headers on my buddies car with a corsa extreme cat back and it also is loud with no drone. it has a different tone in the exhaust than the NPP. only issue is you cannot quiet it down.
i installed kooks long tubes with the x pipe and 3" race cats, i have the factory NPP exhaust, it's LOUD under WOT. there is only one reason why i kept the NPP with a flip of a switch it's quiet.. there is some drone with the factory NPP. i just installed kooks headers on my buddies car with a corsa extreme cat back and it also is loud with no drone. it has a different tone in the exhaust than the NPP. only issue is you cannot quiet it down.
x2 on the Corsa Extreme. No drone and way better exhaust note. Very happy I installed this axle back exhaust.
That's good to know. Did you get any dyno numbers? I don't suppose you have a soundclip?.
Thanks!
I did manage to video the DYNO and Tuning Process. I believe the number was 413HP. I would have to look tonight at my DYNO Sheet to be certain on the numbers. I always ran my GS with the stock exhaust always open. The exhaust note for me is music to my ears
I have a Borla S Classic on mine and am seriously considering headers but am fretting if it getting louder. Still have my original non NPP mufflers to use if it is too loud for my tastes.
Thanks for posting. That's the exact setup I'm looking for. Having the dual mode exhaust is a must for me here in Northern VA. I had a basic Roush Cat Back system (nothing extreme) on my 2014 mustang and got pulled over within 5 minutes of leaving the shop and had to change out the exhaust. I generally keep the npp active as I enjoy the transition from closed to open at 3500k. Thanks again.
I did manage to video the DYNO and Tuning Process. I believe the number was 413HP. I would have to look tonight at my DYNO Sheet to be certain on the numbers. I always ran my GS with the stock exhaust always open. The exhaust note for me is music to my ears
Just an FYI: Billy Boat headers hook up right up without requiring a mid pipe, which I think is a nice option if you want to keep everything else and save a little on cost for little would-be HP gains by not getting a mid pipe.
Last edited by BigMonkey73; Oct 2, 2018 at 04:06 PM.
Or you could buy the Speed Engineering headers and midpipe and pay for installation and still pay $500 less than just buying the Kooks.
You forgot to mention that Speed Engineering charges you for O2 extensions & gaskets. You are not going to get the same quality as Kooks or American Racing Headers.
You forgot to mention that Speed Engineering charges you for O2 extensions & gaskets. You are not going to get the same quality as Kooks or American Racing Headers.
FYI also with Kooks you get EVERYTHING you need for the job plus, and I don't know what kind of hardware/fasteners other makers supply with their kits but I have seen other members who had , shall we say trouble with the ones they got with their kits, all I can say is that the Stage 8 fasteners Kooks includes with theirs is top notch
NSF
Last edited by Not So Fast; Oct 2, 2018 at 08:39 PM.
Some Header Questions
