popping exhaust on engine braking - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

gmhitec · 01-16-2020, 09:43 PM

Hi gang, hope the new year is going well.
Thx for all the help as I find my way in the 5th gen world, last 4 cars have been 2 Z28 and 2 SS 4th gens.
2010 M6 stock except for CAI and a Billy Boat cat back.
Car is amazing compared to the 4th gens, hoping for LT's and a tune in spring. I was shocked at the price of the B&B exhaust when I looked it up, WOW!
I would have put on a chambered system, loved them on 2000 & 2002 SS.
Question, sounds great at idle and under power but under engine braking (deceleration) I'm getting burbling slight popping noise? Is this just the exhaust system or a tuning issue? The car has 55 on the clock.
While I'm at it anyone running a chambered exhaust?

0stones0 · 01-16-2020, 10:11 PM

The popping can be tuned out but, par for the course on a stock setup, imo.

Black_SS10 · 01-17-2020, 05:13 AM

It is called DFCO. Deceleration Fuel Cutoff. Makes the exhaust crackle and pop on deceleration. It can be turned via tune. I think it sounds awesome.

Greenhornet2 · 01-17-2020, 06:51 AM

Yea the injectors are turned off after about 1-2 seconds of no throttle input. Makes the exhaust pop. It's really loud on my car, I kinda like it but it does get annoying on a longer drive. If I get irritated with it I just push the clutch in when decelerating. It also makes my A/F gauge blink red on lean, also irritating.

superschnecke · 01-18-2020, 04:09 PM

What makes popping? Late ignition and fuel. deceleration fuel cut off, timing and transition must be configured ....

pnwdan · 01-18-2020, 05:10 PM

Quote:

Originally Posted by superschnecke

What makes popping? Late ignition and fuel. deceleration fuel cut off, timing and transition must be configured ....

Ignition cuts off. Fuel still fueling. Fuel ignites in the exhaust.

You can see exaggerated examples with cars that they instal 2 step controllers into and set them up to blow flames when letting off the throttle

Greenhornet2 · 01-18-2020, 06:40 PM

Quote:

Originally Posted by pnwdan

Ignition cuts off. Fuel still fueling. Fuel ignites in the exhaust.

You can see exaggerated examples with cars that they instal 2 step controllers into and set them up to blow flames when letting off the throttle

I don't know for sure but i don't think that's how it works on these. If that were the case my A/F would read rich for a few seconds at least, it doesn't, after a second my a/f goes all the way lean telling me the injector is cut off, no fuel then the popping starts. Once the fuel cuts off there isn't enough fuel for a combustion event in the cylinder, then any small amounts of fuel are pushed into the hot exhaust, hits oxygen and snap crackle pop.

gmhitec · 01-21-2020, 08:20 AM

Thx for all the info, living with the popping for now, it sounds kind of cool in a way.
As long is it does not get worse when the LT's go on, of course I will have to do a tune after the install, time will tell.
Thx again everyone!

Greenhornet2 · 01-21-2020, 09:00 AM

As the exhaust gets louder the pops get louder.

SSEssence · 01-21-2020, 09:56 AM

Totally normal and you just don't notice it with stock exhaust. Some people tune to get even more decel pops.

KW Baraka · 01-24-2020, 06:35 PM

Quote:

Originally Posted by Black_SS10

It is called DFCO. Deceleration Fuel Cutoff. Makes the exhaust crackle and pop on deceleration. It can be turned via tune. I think it sounds awesome.

Heavily modified 2014 Chevy SS (Sport Sedan). Mine doesn't do this anymore....wish that it did.

I'm gonna have a little chat with my tuner next week....

KW

InFiD3ViL · 01-24-2020, 06:51 PM

I asked DynoSteve to adjust it in my tune (DFCO) because I love the pops and burbles, but he said No Bueno. He told me it beats up the valves.
But I already have some naturally and I am fine with that...I guess.

It's one of those things that some people love and some people hate.

lemontwist · 01-24-2020, 07:35 PM

Quote:

Originally Posted by InFiD3ViL

I asked DynoSteve to adjust it in my tune (DFCO) because I love the pops and burbles, but he said No Bueno. He told me it beats up the valves.
But I already have some naturally and I am fine with that...I guess.

It's one of those things that some people love and some people hate.

totally stock mine did it a little.
with the magnaflow cat back the snap crackle pop is like ear candy i love it. my tune didn't add to it or reduce it.

Vegas Bound · 01-24-2020, 07:41 PM

It's fun in a busy tunnel.

01-16-2020, 09:43 PM	#1
gmhitec Drives: 77 z28 Join Date: Mar 2017 Location: Callahan FL Posts: 84	popping exhaust on engine braking Hi gang, hope the new year is going well. Thx for all the help as I find my way in the 5th gen world, last 4 cars have been 2 Z28 and 2 SS 4th gens. 2010 M6 stock except for CAI and a Billy Boat cat back. Car is amazing compared to the 4th gens, hoping for LT's and a tune in spring. I was shocked at the price of the B&B exhaust when I looked it up, WOW! I would have put on a chambered system, loved them on 2000 & 2002 SS. Question, sounds great at idle and under power but under engine braking (deceleration) I'm getting burbling slight popping noise? Is this just the exhaust system or a tuning issue? The car has 55 on the clock. While I'm at it anyone running a chambered exhaust?

01-16-2020, 10:11 PM	#2
0stones0 It don’t come easy. Drives: 2010 2SS RS M6 Join Date: May 2014 Location: WI Posts: 2,205 View My Garage	The popping can be tuned out but, par for the course on a stock setup, imo. __________________

01-17-2020, 05:13 AM	#3
Black_SS10 SomeguyK Drives: 2010 Black 2SS/RS Join Date: Nov 2014 Location: FL Posts: 1,947	It is called DFCO. Deceleration Fuel Cutoff. Makes the exhaust crackle and pop on deceleration. It can be turned via tune. I think it sounds awesome. __________________ TMS 427, Dart iron Block, Forged assembly, Frankenstien heads, AGP TT 62/62 BB turbo's, AGP/Fore triple fuel system, Tilton clutch, Holley 1 7/8 shorties, Technostalgia tail lights,Oracle, Aeroforce, MGW shifter,Flowmaster, Pegasus subframe bushings,BMR trailing & toe arms,Z28 UCA bushings,Zl1 rear sway bar,Prothane,BMR,Goodridge brake lines,Ridetech HQ coilovers,3.91,Trutrac,billet caps,DSS axles,HE offest,built TR6060,1LE diffuser,Havoc spoiler,SSclones,20in MRR 017, Pirelli P Zero, Nitto NT555RII More to come.

01-17-2020, 06:51 AM	#4
Greenhornet2 Drives: 2011 Camaro 2SS LS3 Whipple Join Date: May 2019 Location: Connecticut Posts: 1,925	Yea the injectors are turned off after about 1-2 seconds of no throttle input. Makes the exhaust pop. It's really loud on my car, I kinda like it but it does get annoying on a longer drive. If I get irritated with it I just push the clutch in when decelerating. It also makes my A/F gauge blink red on lean, also irritating. __________________ Whipple 2.9 CAI ID1050x injectors ZL1 Pump JRE FPCM JMS Voltage booster JRE Rough Idle blower cam BTR .660 springs CHE trunnion kit 1 7/8 Speed Engineering Borla Atak JRE scoop 1.5" lowering springs BMR trailing arms and toe links Cradle inserts 704WHP 603WTQ 93 octane

01-21-2020, 09:00 AM	#9
Greenhornet2 Drives: 2011 Camaro 2SS LS3 Whipple Join Date: May 2019 Location: Connecticut Posts: 1,925	As the exhaust gets louder the pops get louder. __________________ Whipple 2.9 CAI ID1050x injectors ZL1 Pump JRE FPCM JMS Voltage booster JRE Rough Idle blower cam BTR .660 springs CHE trunnion kit 1 7/8 Speed Engineering Borla Atak JRE scoop 1.5" lowering springs BMR trailing arms and toe links Cradle inserts 704WHP 603WTQ 93 octane

01-18-2020, 04:09 PM	#5
superschnecke Drives: Camaro Join Date: Jan 2019 Location: home Posts: 12	What makes popping? Late ignition and fuel. deceleration fuel cut off, timing and transition must be configured ....

01-21-2020, 08:20 AM	#8
gmhitec Drives: 77 z28 Join Date: Mar 2017 Location: Callahan FL Posts: 84	Thx for all the info, living with the popping for now, it sounds kind of cool in a way. As long is it does not get worse when the LT's go on, of course I will have to do a tune after the install, time will tell. Thx again everyone!

01-21-2020, 09:56 AM	#10
SSEssence Instagram: Sangstah Drives: 2019 Camaro 1LE Join Date: Sep 2016 Location: Buena Park, CA. Posts: 2,803 View My Garage	Totally normal and you just don't notice it with stock exhaust. Some people tune to get even more decel pops. __________________ 2019 SS 1LE - "CaSSandra" 2014 SS - "AleSSandra - Sold" 94 Z28 - Sold Follow the build https://www.camaro6.com/forums/showthread.php?t=612717

01-24-2020, 06:51 PM	#12
InFiD3ViL Drives: 2010 CGM 2SS/RS LS3 Swapped A6 Join Date: Sep 2016 Location: Spring Hill, FL Posts: 4,575	I asked DynoSteve to adjust it in my tune (DFCO) because I love the pops and burbles, but he said No Bueno. He told me it beats up the valves. But I already have some naturally and I am fine with that...I guess. It's one of those things that some people love and some people hate. __________________ 2010 CGM Camaro 2SS LS3 Swapped A6 - GPI LS3 SS1 .647/.638, (224/237, 112 +4, 7º overlap) on CamMotion 8620 core, BTR Platinum .660" Dual Spring kit w/titanium retainers, CHE bronze trunnion upgrade, stock heads milled @ .015, Melling HV 10296 oil pump, TSP 1-7/8" long tube headers (W/Catless Off-road Pipes), Corsa Xtreme 3" Catback, GPI Ported/Rod Mod Intake, Stage 2 Ported Throttle Body, Vararam OTR CAI, Mike Norris Gen 2 catch can + GM 1LE clean side separator, 160º thermostat - Megan Racing adjustable coilovers (lowered 1.75"), MRR M017 10/11" wheels-Tuned by Ryan @ GPI

01-24-2020, 07:41 PM	#14
Vegas Bound Account Suspended Drives: 2013 Sparkly Red One Join Date: Dec 2018 Location: Hospitality State Posts: 2,558	It's fun in a busy tunnel.