ARK DT-S bt.

chii370

well ive only heard 1 IRL with aftermarket. but several G cars. and the only ones that HISS are the ones that say they have test pipes or HFC's installed. why is that? I dont understand whats making the noise. Ah so he was refering to the stock cats that come on the DTS? or the nissans stock exhaust? because the system comes with the entire exhaust from cats to tips and everything in between. So im just confused is all. why would you run the cats off the old stock exhaust on your new DTS?

Chuck33079

Are you sure your new exhaust has cats and not resonators? The cats bolt up to the header. If your exhaust doesn't bolt directly to the header, you're bolting it to the stock cats. It's called a cat back because its everything from the cat back, ie the cat is not a part of it. Put up a pic of the cats on the new exhaust if its unclear. I'm sure we can figure it out.

The hiss comes from the motor. You only hear it with HFCs and TPs because the stock cats block the noise.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

chii370

then what is directly after the X pipe, before the mid pipes? I thought those 2 big cans were the resonators. and BEFORE the X was the cats, two small bulges in the very begining flaring out left and right. Im not unboxing it all just for a quick pic lol just use Nissan 370Z | Burnt Tip 2009-ON | 3.7L, RWD as a reference. Im no exhaust expert, so im not really sure what each section of the exhaust is. aside from the mufflers, thats obvious. From all the vids ive seen the cars running stock cats with their exhausts tend to have a lower tone, no hiss, just generally sound better. Are cats really worth that... 5-6hp you will get to put up with that sound? especially at half the cost of a full exhaust?!! im putting my exhaust on to sound good, couldnt care less about numbers. Once the turbo goes on having an FI/gemini/berk/hks/ark or whatever exhaust wont make one bit of damn difference from one to the other anyway. I just want it to sound good. If that means making 494 hp instead of 500 so be it.

chii370

I see where I went wrong there...... kinda face palming. Yeah Im using the stock cats...... boy I feel stupid now.

Chuck33079

The cans by the mufflers are Helmholtz resonators. There are also two resonators in the X pipe. That exhaust does not have cats in it. It attaches to the factory cats.


ARK Advantages and Features:
- All Bolt-On System
- Helmholtz Design for Minimized Drone
- Burnt Tips
- SUS304 Stainless Steel Construction
- Fully Polished Finish, 2.5 inch Dual Piping
- CNC Machined Flanges
- Exposed Micro TIG Welded

Items Included:
Axle-back Muffler, Mid-pipe, X-flow Y-pipe with resonator, Bolts, Gaskets, Hardware

Some of the resonated hfcs or tps get the hiss down to a manageable level. it's just a sound the motor makes. You'll get more power from hfcs or tps than you will with a cat back, so many people find it worthwhile. It may not be to you if it really bothers you. If you're going turbo later, it's not worth doing anyway. Once the turbo goes on, brand doesn't matter, just diameter. 2.5" will work, but 3" will be more efficient.

You saw it while I was typing. Never mind. Good luck getting it installed. The car is way too quiet stock, so you're going to love being able to hear the motor.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

chii370

actually I had a question about the turbo and diameter. I hear a lot of chatter about 3in piping, but most of the test setups that companies design their turbos and test on all have 2.5 exhausts. example is the FI turbo. And they also mentioned that using 3in they couldnt achieve proper functionality and performance. why is that? I would automatically assume more flow/less resistance=better performance. and is .5 inch diameter really going to restrict air THAT MUCH. is it the difference between 500 and 550? or are we just talking a few puny ponies?

Chuck33079

I'm not sure what you mean by "couldn't achieve proper functionality and performance". For a turbo, bigger is always better. Backpressure is the devil for turbos. A dump tube off the turbine housing would be the perfect turbo exhaust, but it would be insanely loud. The flow difference between 2.5 and 3 inches is pretty big. It's not straight math.

It may not be as noticeable as making X power vs Y power. If its running more efficiently, you may make the same power on less boost, leading to a cooler intake charge and a less stressed motor.

Most companies use 2.5 inch exhausts because they can sell them to every 370. A 3" exhaust on a NA 370 would most likely be way too big. As few turbo 370s as there are out there, its hard for a business to justify making an exhaust that so few people can use. There's only GTM and FI as far as I know.

__________________
2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

rAiN

I have dts on my car, im gon drive down to manassas to get some starbucks soon.

chii370

At 9pm? lol I had no idea sb was open 24 hours Im in manassas park, so there are probably 3971.5 SB's between you and I. Which one.....?

rAiN

Gatta get my hot white choco before sleep, that starbucks is on sudley manor dr.

chii370

:O vinte white chocolate mocha with whip cream, 2 packs of hawaii raw sugar and some vanilla powder...... the perfect drink. before bed though? might wanna go get that checked out. lemme know the next time your going up there at a normal time. As i have work lol.

rAiN

Welp son come check it out if you wanna hear it.

imwazn

Check the mid-atlantic part of the forum. I'm sure you can find somebody to help you out around where you are.

chii370

exhaust is on the car. OMFG it sounds amazing. its MUCH louder than i thought it would be...... which im not a huge fan of, but zero rasp, zero drone. local shop installed it and allowed me to HELP THEM and only charged me 100 bucks called pauls auto in manassas. so now the nismo exhaust is off the car and sitting at my house.


sound clips dont sound like the real thing AT ALL. its not even close. unless your rockin a 3000$ camera with a mic the size of your fist.

chii370

so uh..... couple questions. first, it seems a bit down on HP. Second, why is it running hotter than usual? I asked several times if i would need a tune, and everyone said no. sure? and no, the pipes were free and clear upon install, no obstructions. sounds perfect, no leaks, no rattle, no buzz. so this leads me to believe that the car needs tuned........ I dont understand how lowering back pressure on an NA engine would have ANY effect on it at all. intake side yes, exhaust side no. WTF IS GOING ON!!!! maybe there is a drop in flow VELOCITY??? im not sure if the ark DTS is any bigger diameter than the nismo, I think they are both 2.5. But I do know that its not MORE restrictive, so its not back pressure...... only thing i can think of is that there was a drop in exhaust velocity which is a bad thing. Im going to go have it tuned to see its a real issue or not, couldnt hurt anyway as even the stock nismo tune is pretty conservative compared to tuning it for stupid tree hugging hippy gas consumption reasons. I dont care if my car gets 15 mpg as long as it runs like a sports car should.

sounds good though....