Love the car, hate the raspy sound. Which exhaust to buy? - Page 3

cmitchell17 · 06-12-2021, 09:05 PM

Quote:

Originally Posted by Tankk

All I can say is when I hit the remote start button on my ZL1 is that people jump and their jaws hit the floor.

Yeah I can't believe GM released it being as loud as it is especially start up and especially startup in cat warmup mode.

BruceWayne1LE · 06-12-2021, 09:33 PM

Long tube headers to MBRP catback is a good option.

UnknownJinX · 06-12-2021, 10:02 PM

Quote:

Originally Posted by cmitchell17

Yeah I can't believe GM released it being as loud as it is especially start up and especially startup in cat warmup mode.

My friend who has a Hellcat Charger has a theory that it's just the nature of pushrod V8s. Stock for stock, my other friend's Mustang GT can be pretty tamed when starting up, definitely not the same as my Camaro or my friend's Hellcat Charger.

Sent from my MHA-L29 using Tapatalk

cmitchell17 · 06-13-2021, 10:07 PM

Quote:

Originally Posted by UnknownJinX

My friend who has a Hellcat Charger has a theory that it's just the nature of pushrod V8s. Stock for stock, my other friend's Mustang GT can be pretty tamed when starting up, definitely not the same as my Camaro or my friend's Hellcat Charger.

Sent from my MHA-L29 using Tapatalk

I think I remember some discussion about it on here and maybe someone, I think?, mentioned they got around some CFR noise requirement at some point in operation I think.

Crushin_LT1 · 06-14-2021, 06:41 AM

I was under the impression it was an EPA thing for cold starts, gets the cats warmed up.

KingLT1 · 06-14-2021, 09:22 AM

Quote:

Originally Posted by UnknownJinX

My friend who has a Hellcat Charger has a theory that it's just the nature of pushrod V8s. Stock for stock, my other friend's Mustang GT can be pretty tamed when starting up, definitely not the same as my Camaro or my friend's Hellcat Charger.

Sent from my MHA-L29 using Tapatalk

It's mostly tuning related. You can tame them a lot on cold start by changing the some stuff in the tune. CSP has a video on it back when he bought his wife the silver convertible SS.

avalonandl · 06-14-2021, 09:58 AM

Its to light the cats faster is why the cold start is loud. Once the cats light up you burn cleaner.

Aaron07 · 06-15-2021, 05:41 AM

Quote:

Originally Posted by avalonandl

Its to light the cats faster is why the cold start is loud. Once the cats light up you burn cleaner.

That's what I've always heard.

KingLT1 · 06-15-2021, 09:39 AM

It's a fact.

SilverSurfer18 · 06-15-2021, 02:12 PM

Quote:

Originally Posted by avalonandl

Its to light the cats faster is why the cold start is loud. Once the cats light up you burn cleaner.

Is there a way to tune this out? No need for the high rev when started now since I have longtubes and no cats....

KingLT1 · 06-15-2021, 03:27 PM

Didn't I just previously say you can tune it out? Lol

cmitchell17 · 06-15-2021, 08:22 PM

Its still loud even when you disable catalyst warmup mode. There is just very little attenuation at those frequencies during startup. Disabling cat warmup mode does help mainly by getting it down to idle faster instead of hanging at startup and the timing is a lot more retarded in cat warmup mode and that makes it louder too.

hotlap · 06-16-2021, 08:07 AM

I noticed immediately that my 20 SS 1LE exhaust is louder at wide open throttle and has more crackle than my 16 or 18.

The 16 and 18 were both 2SS with NPP. The 16 was A8. The 18 was M6.

I thought I read in the past that Chevy recalibrated for more crackle when you lift off the accelerator. Did they also tweak the muffler?

My 20 has the Chevy Performance Cold Air Intake with tune. I don't see that resulting in the louder WOT or crackle.

Anyway ...I like it. NPP is set to track in my personalization.

06-12-2021, 09:33 PM	#30
BruceWayne1LE Drives: 2018 Camaro SS 1LE M6 Join Date: Oct 2018 Location: Northern California Posts: 345	Long tube headers to MBRP catback is a good option. __________________ Camaro 2SS 1LE, MBRP Catback, Mishimoto Catch Can, Rotofab dry, TSP1 7/8” headers,DSX FF, Pray ported MSD, 95mm TB 492WHP 473WTQ

06-14-2021, 06:41 AM	#33
Crushin_LT1 Drives: 2021 LT1 6spd Join Date: Nov 2020 Location: Arlington, VA Posts: 767	I was under the impression it was an EPA thing for cold starts, gets the cats warmed up. __________________ Current: 2021 LT1 Camaro, 6spd, Crush, Corsa NPP, GMPP CAI, Soler Performance Throttle controller Previous: 1997 V6 Camaro, 5spd, Black

06-14-2021, 09:58 AM	#35
avalonandl Drives: 2019 ZL-1 Join Date: Feb 2009 Location: Troy, MI & Naples, FL Posts: 2,019	Its to light the cats faster is why the cold start is loud. Once the cats light up you burn cleaner. __________________ 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

06-15-2021, 09:39 AM	#37
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,793	It's a fact. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

06-15-2021, 03:27 PM	#39
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,793	Didn't I just previously say you can tune it out? Lol __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

06-15-2021, 08:22 PM	#40
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,200	Its still loud even when you disable catalyst warmup mode. There is just very little attenuation at those frequencies during startup. Disabling cat warmup mode does help mainly by getting it down to idle faster instead of hanging at startup and the timing is a lot more retarded in cat warmup mode and that makes it louder too.

06-16-2021, 08:07 AM	#41
hotlap Drives: 20 1LE 2SS M6 Rally Green Join Date: Mar 2014 Location: Franklin WI Posts: 6,632	I noticed immediately that my 20 SS 1LE exhaust is louder at wide open throttle and has more crackle than my 16 or 18. The 16 and 18 were both 2SS with NPP. The 16 was A8. The 18 was M6. I thought I read in the past that Chevy recalibrated for more crackle when you lift off the accelerator. Did they also tweak the muffler? My 20 has the Chevy Performance Cold Air Intake with tune. I don't see that resulting in the louder WOT or crackle. Anyway ...I like it. NPP is set to track in my personalization. __________________ "the trouble with our liberal friends is not that they're ignorant; it's just that they know so much that isn't so.” Ronald Reagan -

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