long tube headers with stock Npp ?
06-23-2016, 02:21 PM
#1
Drifting
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St. Jude Donor '13
long tube headers with stock Npp ?
Just curious if anyone has long tube headers and stock Npp exhaust , I would imagine that obviously the sound is different, but HOW different as in deeper ? and if louder, how much compared to the npp with the valves open ? thanks Scott.
06-23-2016, 02:24 PM
#2
I think mine sounds amazing. I have Kooks 1-7/8" headers with their catless x-pipe and stock factory NPP. I have the DashLogic which allows me to keep the valves always open, normal factory operation, or always closed. I love the way it sounds under all conditions. I daily drive my vette, almost 100k miles on it, so I keep it in normal mode 95% of the time. When I go out with some friends, or to a meet or show, I keep it open. It's definitely louder than stock manifolds. But I also making more power than stock by a bit. With the valves closed, it's a tiny bit louder, but that's more due to my big cam.
Last edited by jesse82nc; 06-23-2016 at 02:25 PM.
06-23-2016, 03:20 PM
#4
Intermediate
Just had CPR install ARH long tubes with no cats on my 2010 ZR1. Stock with NPP and M2W switch. Whisper quiet with the valves closed and windows up. Insanely bad *** with them open. How it shouldve sounded from the factory. Best of both worlds. Do eeeeet!!
06-23-2016, 09:05 PM
#7
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C6 of Year Finalist (performance mods) 2019
'08 A6 catless LG Streets with Z06 mufflers, so I can't really compare to stock NPP mufflers.
Went from OEM to the Z06 mufflers around 12K, then added Z06 manifolds to H-pipe about 36K, then LG headers around 80K. I'm currently at 132K and I still like it open, except on long trips with the wife where the 1300-1600 drone still exists then I close the valves.
Obviously the sound from OEM to Z06 mufflers was significant, but from there, the differences were fairly slight.
Went from OEM to the Z06 mufflers around 12K, then added Z06 manifolds to H-pipe about 36K, then LG headers around 80K. I'm currently at 132K and I still like it open, except on long trips with the wife where the 1300-1600 drone still exists then I close the valves.
Obviously the sound from OEM to Z06 mufflers was significant, but from there, the differences were fairly slight.
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s n v f f (07-23-2019)
06-24-2016, 08:55 AM
#9
Burning Brakes
06-24-2016, 08:55 AM
#10
The NPP combined with LTs is literally the best of both worlds. It's nice and quiet with the valve closed and screams like a Ferrari V8 on steroids @ WOT. The only thing different about the sound at idle with the LTs is the tinny ringing of the exhaust due to the headers being thin pipe rather than thick cast iron. But I love the sound of that anyways.
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s n v f f (07-23-2019)
06-24-2016, 09:55 AM
#11
I have 1 7/8 ARH with high flow cats and NPP. nice and quiet when closed (even with the 231/239 cam, and ECS1500). LOUD when open, IN-FREAKIN-SANE when the remote cutouts are open!
06-24-2016, 10:34 AM
#12
Intermediate
little louder with the valve closed. butwhen open everyone knows it once your really get in it . but just driving at normal speeds there is a little drone to it but other than that i love it !!! henson headers catless mids
06-24-2016, 11:07 PM
#13
Le Mans Master
The NPP combined with LTs is literally the best of both worlds. It's nice and quiet with the valve closed and screams like a Ferrari V8 on steroids @ WOT. The only thing different about the sound at idle with the LTs is the tinny ringing of the exhaust due to the headers being thin pipe rather than thick cast iron. But I love the sound of that anyways.
Man when they are open and you are on it, everyone knows it.......sounds awesome !!! It's loud
Then when u close them ......like driving a hearse lol
Dave
03-31-2017, 06:59 AM
#14
I think mine sounds amazing. I have Kooks 1-7/8" headers with their catless x-pipe and stock factory NPP. I have the DashLogic which allows me to keep the valves always open, normal factory operation, or always closed. I love the way it sounds under all conditions. I daily drive my vette, almost 100k miles on it, so I keep it in normal mode 95% of the time. When I go out with some friends, or to a meet or show, I keep it open. It's definitely louder than stock manifolds. But I also making more power than stock by a bit. With the valves closed, it's a tiny bit louder, but that's more due to my big cam.
03-31-2017, 07:47 AM
#15
1 7/8" ARH's here with cats and stock NPP, I can not imagine anything better than what I got. Love it both when closed and open!
03-31-2017, 08:38 AM
#16
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2021 C6 of the Year Finalist - Modified
I installed a set of Pfadt long tube headers along with there catted x-pipe.
With the NPP valves closed, the sound was just slightly louder than with the stock exhaust manifolds and NPP valves closed ... nothing bad at all. Actually really nice.
But, when the NPP valves were open at full throttle, my 2011 GS was obnoxiously loud! Much louder than with the stock exhaust manifolds and the NPP valves fully open.
My fix for this was to remove the NPP mufflers and install a set of Borla "Touring" mufflers .... perfect with the headers now.
With the NPP valves closed, the sound was just slightly louder than with the stock exhaust manifolds and NPP valves closed ... nothing bad at all. Actually really nice.
But, when the NPP valves were open at full throttle, my 2011 GS was obnoxiously loud! Much louder than with the stock exhaust manifolds and the NPP valves fully open.
My fix for this was to remove the NPP mufflers and install a set of Borla "Touring" mufflers .... perfect with the headers now.
03-31-2017, 08:52 AM
#17
Instructor
I bought my car with Kooks long tube headers and x pipe with the stock NPP. It is catless and I wondered if they had to tune it since the cats were removed so it wouldn't give any codes.
Does anyone know if you need a tune if you go catless?
Does anyone know if you need a tune if you go catless?
03-31-2017, 05:04 PM
#18
Yeah, you would know if it wasnt tuned. I have same set up with a fast 102 intake and larger throttle body, if you dont tune you dont get the hp gains out of breather mods and if you are goig to go that far with it, why not tune it. Usually get better gas mileage with a tune too. I have 435hp to the wheels and still get 26.5 on the hiehgway crusing at 80! Pretty crazy.
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gbslagle (04-01-2017)