Exhaust pops - Is this a problem?

[Mr. iNCREDIBLE]

Originally Posted by BAD ZL1

Wierd, I never heard of that. Where are they located, inside the mufflers?

I used to hear a rattle sound when my dual mode exhaust flappers would open and close and the rattle is gone since I pulled the fuse. I am curious to learn more about what you are talking about. I am not familiar with that at all. I have a buddy that has a 2013 vert. I'll have to ask him if he hears anything other than the dual mode exhaust flappers.....

here is a quick picture I just took, these are located just behind the center resonator, just in front of the rear mufflers..



now I had my rear over-sized 600 lbs mufflers cut off and put straight pipes from axel back, as a result I can now hear these things opening and closing..

That in of it self doesn't bother me, the exhaust note isn't the issue, it is the metal rattle sound that is heard that bugs me.

from what the dealer and my exhaust guy (whom I have know for 20 odd years and has done exhaust on all of my cars since the late 80s) have told me, these are there to kill the droning sound caused by AFM mode. They are activated strictly by the resonance sound of the exhaust, they are most noticable first thing in the morning as everything is cold, and I hear them constantly during low speed (stop and go) driving.

[tonyfred]

I love the ZL1 exhaust but hate that popping. When I was young the only time a performance car popped like that was when it needed a tune up. Ugh.

[Camaro X]

The popping is a major problem! It means you have let up on the accelerator and are slowing down.

[Misterleeman]

Originally Posted by Camaro X

The popping is a major problem! It means you have let up on the accelerator and are slowing down.

[DuskSS]

Originally Posted by BAD ZL1

Wierd, I never heard of that. Where are they located, inside the mufflers?

I used to hear a rattle sound when my dual mode exhaust flappers would open and close and the rattle is gone since I pulled the fuse. I am curious to learn more about what you are talking about. I am not familiar with that at all. I have a buddy that has a 2013 vert. I'll have to ask him if he hears anything other than the dual mode exhaust flappers.....

My DM is rattling so bad it is driving me nuts..
500 mile old car and it rattles so bad back there.

[DangerZL1]

I believe the popping is due to a fuel cutoff when letting off the gas not allowing more fuel into the combustion chamber. This is done to save fuel and can be tuned out by a tuner. I don't like it either, but at least it isn't a problem.

[IcePick06]

popping is nothing to worry about. My C6 did the same thing with aftermarket exhaust (never had it tuned either), only happens when you let off the accelerator, I actually like the sound of it, sounds very "race-car" like!

[hognutz]

google deceleration fuel cut off or (DFCO). I dont' like it and probabaly will tune it out. I like to hear an engine rev not backfire. it is supposedly good for 1-2% fuel economy.

Most don't truely understand why it is happening you will hear all kinds of explanations of the forums.

Many people who are used to carburated cars percieve a problem because if you carb ever sounded like this you would have a problem. you can't cut fuel on a carb though there is always some sort of fuel delivery.

I have never really liked it. my 66 chevelle and 69 Camaro sounded better to me withough this popping than my 08 Z51 or my 207 Z06. it seems even worse on this car.

[Mr pogo]

just looking at the some of the google info and the hits from years back, looks like on LS engines the injectors are still pulsing some fuel during DFCO operation which makes sense.
you have to have some fuel delivery to cause back popping.
if there was zero fuel during DFCO there would be zero back popping so my guess to program it out the injectors go to zero pulsewidth during DFCO.

and back in the day back popping on stock carb engines usually meant burnt or too tight exhaust valves or weak ignition spark.

[ka1]

Originally Posted by eightup

thats called barking

and I love it personally

[davidcroft]

Originally Posted by Mr. iNCREDIBLE

here is a quick picture I just took, these are located just behind the center resonator, just in front of the rear mufflers..



now I had my rear over-sized 600 lbs mufflers cut off and put straight pipes from axel back, as a result I can now hear these things opening and closing..

That in of it self doesn't bother me, the exhaust note isn't the issue, it is the metal rattle sound that is heard that bugs me.

from what the dealer and my exhaust guy (whom I have know for 20 odd years and has done exhaust on all of my cars since the late 80s) have told me, these are there to kill the droning sound caused by AFM mode. They are activated strictly by the resonance sound of the exhaust, they are most noticable first thing in the morning as everything is cold, and I hear them constantly during low speed (stop and go) driving.

isn't this a ZL1 forum? That's only L99 cars!

[Mr. iNCREDIBLE]

Originally Posted by davidcroft

isn't this a ZL1 forum? That's only L99 cars!

didn't even notice it was the ZL1 forum, picked the topic off of the new posts page.

[ZL1ster]

Like the 'pop'...growl and all the other nasty noise that comes out of this beast!

Did the "EXH FLAP" (10amp) fuse pull located in the trunk.

Threw the fuse in the glove box...and there it stays

Sounds S!cK!!!

[2ss-booya]

Originally Posted by ZL1ster

Like the 'pop'...growl and all the other nasty noise that comes out of this beast!

Did the "EXH FLAP" (10amp) fuse pull located in the trunk.

Threw the fuse in the glove box...and there it stays

Sounds S!cK!!!

^^ This lol. I pulled the fuse after 1 day of having the car...looked at my fiance and said OH MY GODD I like that

she wasn't so thrilled though....but she'll get used to it