Should NPP Stealth mode still crackle

DetCam · 08-07-2018, 11:26 AM

I utilize my stealth mode on the NPP exhaust for exactly what the name implies... being stealthy.

The stealth mode exhaust does seem to do it's job during the slowest of scenarios, but trying to use even a quarter of the power we have, I get the "Crackle" of the exhaust coming through. Without the healthy roar of the V8 coming through the outer pipes, the crackle just sounds like something is broken. Which got me wondering.... is it broken? Does everyone else get the crackle/rattle sound when using Stealth mode?

Does anyone have a good video with decent audio of what their Stealth mode sounds like?

USAFS197 · 08-07-2018, 01:16 PM

Mine still pops while in stealth mode. I mean, the car is still going to do what it does, regardless of how you setup the exhaust modes so, the popping, as much as I loathe it, should still be present but, just muted in stealth mode.

enzia35 · 08-07-2018, 02:51 PM

Could it be the NPP rattle that has the TSB out for it?

DetCam · 08-08-2018, 07:44 AM

I suppose it could be the NPP rattle, I just haven't found a good video of NPP Rattle driving on Stealth mode. (I don't have any rattles at idle).

Unfortunately I think USAFS197 is correct, and it's just what the car does.

avalonandl · 08-08-2018, 09:40 AM

Yes car will crackle especially when warming up.

JaxChris · 08-09-2018, 12:30 PM

Stealth mode cold starts are the easiest way to get the NPP valve rattle. Stealth mode should only be expected to work well under 2200 rpm, after that the exhaust gas volume is sufficient to build backpressure and grumbling will be heard. It's only really there for driving through your neighborhood with the sound of a Camry. Accelerate too fast or get above 30mph and you will hear things coming from the exhaust.

USAFS197 · 08-09-2018, 02:38 PM

Unless I'm driving my car hard, it stays in stealth mode 100% of the time, now. It's just too obnoxious otherwise. I'll likely add some stuff to my exhaust to quiet it down over time but for now, stealth mode works ok.

retmil · 08-09-2018, 03:17 PM

My '17 tends to "crackle" less after engine warms up.

VinnAY · 08-10-2018, 07:47 AM

Stealth is very poorly named.

HighIron · 08-10-2018, 10:33 AM

Quote:

Originally Posted by VinnAY

Stealth is very poorly named.

I agree. It's only stealth in comparison with the open modes. It's still very healthy sounding and certainly more noticeable than other stock V8 powered cars.

08-07-2018, 11:26 AM	#1
DetCam Drives: 2016 1SS (12/10/2016) Join Date: Jul 2015 Location: Troy MI Posts: 169	Should NPP Stealth mode still crackle I utilize my stealth mode on the NPP exhaust for exactly what the name implies... being stealthy. The stealth mode exhaust does seem to do it's job during the slowest of scenarios, but trying to use even a quarter of the power we have, I get the "Crackle" of the exhaust coming through. Without the healthy roar of the V8 coming through the outer pipes, the crackle just sounds like something is broken. Which got me wondering.... is it broken? Does everyone else get the crackle/rattle sound when using Stealth mode? Does anyone have a good video with decent audio of what their Stealth mode sounds like?

08-07-2018, 01:16 PM	#2
USAFS197 Drives: 2018 Audi TT RS Join Date: Jan 2014 Location: Navarre, Florida Posts: 1,915	Mine still pops while in stealth mode. I mean, the car is still going to do what it does, regardless of how you setup the exhaust modes so, the popping, as much as I loathe it, should still be present but, just muted in stealth mode. __________________ 2018 Audi TT ▊RS 2.4X 0-60, 1.6X 60', 120+mph 1/8th, 4.XX 60-130, 150+mph traps on 255/35/18 R888R tires on the street (unprepped). 2019 Audi RS3 About as fast as the TT RS 2019 Camaro ZL1 1LE Sold 2018 Camaro SS 1LE Sold 2019 Corvette Z06 Sold 2021 Charger Hellcat Redeye Widebody Sold

08-07-2018, 02:51 PM	#3
enzia35 Drives: '16 Garnet Red 1SS Join Date: Mar 2014 Location: College Station, TX Posts: 3,450	Could it be the NPP rattle that has the TSB out for it? __________________ '16 Camaro 1SS '18 Miata GT Gone: '01 Camaro, '14 Camaro, '90 Miata

08-08-2018, 09:40 AM	#5
avalonandl Drives: 2019 ZL-1 Join Date: Feb 2009 Location: Troy, MI & Naples, FL Posts: 2,019	Yes car will crackle especially when warming up. __________________ 2019 ZL-1 Acquired 4/23/21 at 6300 miles. Riverside Blue, A10, PDR. Traded in 2017 2SS with 6M and 32k miles. Continental Extreme Contact Sports. Now has 10,000 miles... 2012 Yukon XL Denali w/ 6.2 AWD

08-09-2018, 02:38 PM	#7
USAFS197 Drives: 2018 Audi TT RS Join Date: Jan 2014 Location: Navarre, Florida Posts: 1,915	Unless I'm driving my car hard, it stays in stealth mode 100% of the time, now. It's just too obnoxious otherwise. I'll likely add some stuff to my exhaust to quiet it down over time but for now, stealth mode works ok. __________________ 2018 Audi TT ▊RS 2.4X 0-60, 1.6X 60', 120+mph 1/8th, 4.XX 60-130, 150+mph traps on 255/35/18 R888R tires on the street (unprepped). 2019 Audi RS3 About as fast as the TT RS 2019 Camaro ZL1 1LE Sold 2018 Camaro SS 1LE Sold 2019 Corvette Z06 Sold 2021 Charger Hellcat Redeye Widebody Sold

08-08-2018, 07:44 AM	#4
DetCam Drives: 2016 1SS (12/10/2016) Join Date: Jul 2015 Location: Troy MI Posts: 169	I suppose it could be the NPP rattle, I just haven't found a good video of NPP Rattle driving on Stealth mode. (I don't have any rattles at idle). Unfortunately I think USAFS197 is correct, and it's just what the car does.

08-09-2018, 12:30 PM	#6
JaxChris Drives: '16 2SS GD1 MX0 NPP F55 IO6 Join Date: Jun 2013 Location: Florida Posts: 1,298	Stealth mode cold starts are the easiest way to get the NPP valve rattle. Stealth mode should only be expected to work well under 2200 rpm, after that the exhaust gas volume is sufficient to build backpressure and grumbling will be heard. It's only really there for driving through your neighborhood with the sound of a Camry. Accelerate too fast or get above 30mph and you will hear things coming from the exhaust.

08-09-2018, 03:17 PM	#8
retmil Drives: 2022 Wild Cherry SS Join Date: Aug 2012 Location: Germantown, Md Posts: 316	My '17 tends to "crackle" less after engine warms up.

08-10-2018, 07:47 AM	#9
VinnAY Account Suspended Drives: 18 1SS/1LE Join Date: Jun 2018 Location: Missouri Posts: 939	Stealth is very poorly named.

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