Saabkyle04: NPP Exhaust Review

BahamaTodd · 01-22-2016, 09:48 PM

Nice review of the NPP exhaust in all settings - exterior and interior.

The stealth mode start-up was unusually loud.

RenegadeXR · 01-22-2016, 10:20 PM

Very nice video. But dang, now I see why people were saying that the bypass valve on the NPP exhaust is loud when switching modes. Doesn't sound too refined.

And yeah, the start up in stealth mode was a bit loud, although they might have used a sensitive microphone during recording. When I test drove a 1SS with NPP, it was in tour mode and the start up was extremely quiet in person.

Toxicgoober · 01-22-2016, 10:42 PM

Same here when I tested a 1SS earlier in the week. Good thing, though, is that I couldn't tell any significant drone in the cabin, even in track mode.

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bybcous · 01-22-2016, 11:01 PM

My 1ss starts up loud ass hell in steslth mode but immedistely calms down. I think that is how it is designed but i wish it was start up quiet

SuperSound · 01-23-2016, 12:07 PM

Quote:

Originally Posted by bybcous

My 1ss starts up loud ass hell in steslth mode but immedistely calms down. I think that is how it is designed but i wish it was start up quiet

Yea think I heard from an engineer that on cold start the valve is open for longer than you would think. Compare it to the warm start in stealth and it's obvious. You hear it immediately shut.

SS 1LE · 01-23-2016, 12:14 PM

Cold start crank time is oddly long?

Glen e · 01-23-2016, 12:21 PM

The LT1 one start up is slightly longer due to the DI needing to pressurize… That was on the Corvette site last year from a GM engineer.

SuperSound · 01-23-2016, 12:21 PM

Quote:

Originally Posted by SUMMIT WHITE SS

Cold start crank time is oddly long?

Yep. There was a thread awhile back about how the C7s have long cold starts. Think someone even mentioned the owners manual lists some long times in cold climates.

suzook · 01-23-2016, 02:15 PM

Quote:

Originally Posted by SuperSound

Yep. There was a thread awhile back about how the C7s have long cold starts. Think someone even mentioned the owners manual lists some long times in cold climates.

Yep, cold starts are insanely delayed. I actually thought my car was not gonna start this morning. Wonder why its so much different than the ls motor? Maybe pre lube components?

Glen e · 01-23-2016, 02:19 PM

Once again, its the DI.....as it gets colder, it takes longer to pressurize. The DI System needs a huge amount of pressure

SSport16 · 01-23-2016, 02:25 PM

Yeah it is longer, but nothing crazy. Just takes a few times to get used to. I am assuming that the larger the displacement of the engine using DI, the longer it takes. My 3.6 L DI in my SRX does not take that long, but obviously a much smaller 2 less cylinder engine.

SSport16 · 01-23-2016, 02:28 PM

Quote:

Originally Posted by Glen e

Once again, its the DI.....as it gets colder, it takes longer to pressurize. The DI System needs a huge amount of pressure

Do you ever feel that nobody listens to you when you speak? LMAO!

Maybe you need one of these.

Glen e · 01-23-2016, 02:31 PM

yeah....LOL

SuperSound · 01-23-2016, 02:51 PM

Quote:

Originally Posted by SSport16

Yeah it is longer, but nothing crazy. Just takes a few times to get used to. I am assuming that the larger the displacement of the engine using DI, the longer it takes. My 3.6 L DI in my SRX does not take that long, but obviously a much smaller 2 less cylinder engine.

Yep, most people are probably more used to 4 cylinders with DI start times, than a large displacement V8 with it.

01-22-2016, 11:01 PM	#4
bybcous Drives: 2016 Hyper Blue 1SS Join Date: Jul 2015 Location: hampton roads Posts: 2,763	My 1ss starts up loud ass hell in steslth mode but immedistely calms down. I think that is how it is designed but i wish it was start up quiet __________________ 1ss/Auto-Hyper Blue acs carbon flash spoiler, bmr springs, gm clear tails. Texas speed cam, 223/227 .635/.635 116 LSA, Kooks Long Tube Headers with green cats, MSD Atomic Air Force Intake, CAI Cold Air Intake, QTP cutouts. 503 hp Best so far 11.5 at 123 with a 1.83 60ft. BMR lower and upper trailing arms and upper control arms,E85 DELIVERED 12/29/15 http://youtube.com/bybcous " no talking only racing on my youtube"

01-23-2016, 12:21 PM	#7
Glen e Retired from Car mfrs.... Drives: 2LT RS/HR-V Join Date: May 2013 Location: /Fort Lauderdale Posts: 10,048	The LT1 one start up is slightly longer due to the DI needing to pressurize… That was on the Corvette site last year from a GM engineer. __________________ Glen CLICK HERE for detailing a new car: detailing for non detailers CLICK HERE for how to rinseless CLICK HERE for EASY wheel sealant

01-23-2016, 02:19 PM	#10
Glen e Retired from Car mfrs.... Drives: 2LT RS/HR-V Join Date: May 2013 Location: /Fort Lauderdale Posts: 10,048	Once again, its the DI.....as it gets colder, it takes longer to pressurize. The DI System needs a huge amount of pressure __________________ Glen CLICK HERE for detailing a new car: detailing for non detailers CLICK HERE for how to rinseless CLICK HERE for EASY wheel sealant

01-23-2016, 02:25 PM	#11
SSport16 Drives: 2016 Garnet Red Camaro 2SS Join Date: Jul 2015 Location: North Carolina Posts: 5,435	Yeah it is longer, but nothing crazy. Just takes a few times to get used to. I am assuming that the larger the displacement of the engine using DI, the longer it takes. My 3.6 L DI in my SRX does not take that long, but obviously a much smaller 2 less cylinder engine. __________________ 2SS Camaro, Garnet Red, Adrenaline Red, NPP, MRC, A8, 5 Split Spoke Bright Silver Wheels (56W) 1100 Status - 7/24/15 (Ordered) 3800 Status - 10/13/15 (Built) 6000 Status - 12/22/15 (Delivered)

01-23-2016, 02:31 PM	#13
Glen e Retired from Car mfrs.... Drives: 2LT RS/HR-V Join Date: May 2013 Location: /Fort Lauderdale Posts: 10,048	yeah....LOL __________________ Glen CLICK HERE for detailing a new car: detailing for non detailers CLICK HERE for how to rinseless CLICK HERE for EASY wheel sealant

01-22-2016, 10:20 PM	#2
RenegadeXR Drives: 2011 Camaro SS Join Date: Apr 2013 Location: North Carolina Posts: 1,849	Very nice video. But dang, now I see why people were saying that the bypass valve on the NPP exhaust is loud when switching modes. Doesn't sound too refined. And yeah, the start up in stealth mode was a bit loud, although they might have used a sensitive microphone during recording. When I test drove a 1SS with NPP, it was in tour mode and the start up was extremely quiet in person.

01-22-2016, 10:42 PM	#3
Toxicgoober Drives: 2014 Maxima Join Date: Dec 2015 Location: Louisiana Posts: 280	Same here when I tested a 1SS earlier in the week. Good thing, though, is that I couldn't tell any significant drone in the cabin, even in track mode. Sent from my iPhone using Tapatalk

01-23-2016, 12:14 PM	#6
SS 1LE マスタング = 遅い Drives: 2017 Chevrolet Camaro SS 1LE Join Date: Aug 2015 Location: Florida Posts: 7,061	Cold start crank time is oddly long?

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