Go Back   Corvette Forum > C6 Corvette, 2005 - 2013 > C6 Z06 Discussion
Sign in using an external account
Register Forgot Password?
Register Search Today's Posts Mark Forums Read FAQ Vendor Directory
Search
C6 Z06 Discussion
General Z06 Corvette Discussion, LS7 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track Sponsored by
PFYC

Welcome to Corvetteforum.com!
Welcome to Corvetteforum.com.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Corvetteforum.com today!


Corvette Store
 
 
C7 Parts & Accessories
C6 Parts & Accessories
C5 Parts & Accessories
C4 Parts & Accessories
C3 Parts & Accessories
C2 Parts & Accessories
C1 Parts & Accessories
Wheels & Tires
Sponsored Ads
 
 
Vendor Directory
  
Reply
 
 
 
 
Thread Tools Search this Thread
Old 03-17-2011, 12:08 AM   #1
JMB
CF Senior Member
 
Member Since: Aug 2000
Location: Tacoma, WA USA
Default How do you get rid of the "exhaust popping" on deceleration?

I've just purchased a 2011 Z06 and the only thing that drives me up the wall about this car is the hidious sounding popping coming from the exhaust when the car is decelerating in gear or between spirited shifts This sound reminds me of a cheap car with leaky header gaskets!

Are there moisture drain holes or something else that needs to be plugged on the head pipes to cure this? What is causing this? I've tried to do a search on this forum but came up empty handed.
JMB is offline   Reply With Quote
Old 03-17-2011, 12:13 AM   #2
tim414
CF Senior Member
St. Jude Donor '12
Support Corvetteforum!
 
tim414's Avatar
 
Member Since: Jan 2009
Location: Pottsboro; Sometimes Dallas Texas
Default

Quote:
Originally Posted by JMB View Post
I've just purchased a 2011 Z06 and the only thing that drives me up the wall about this car is the hidious sounding popping coming from the exhaust when the car is decelerating in gear or between spirited shifts This sound reminds me of a cheap car with leaky header gaskets!

Are there moisture drain holes or something else that needs to be plugged on the head pipes to cure this? What is causing this? I've tried to do a search on this forum but came up empty handed.
X-pipe perhaps?
tim414 is offline   Reply With Quote
Old 03-17-2011, 12:19 AM   #3
DriftKing
CF Senior Member
 
DriftKing's Avatar
 
Member Since: Dec 2010
Location: Canton GA
Default

That is actually an enhancement starting in 2011 ... described at 4:30 http://www.youtube.com/watch?v=YOvS3JN4AKM
__________________
2008 C6Z: 501 whp/484 wtq; PB: 1.594 60', 10.771@130.96 Slip Vid
Vararam, American Racing headers/x-pipe/cats, ported TB, 180* stat, NGK TR55, tune.

2008 Challenger SRT: SOLD

"I'm gonna give you an engine low to the ground... extra thick oil pan to cut the wind from underneath you. It'll give you thirty or forty more horsepower. I'm gonna give you a fuel line that'll hold an extra gallon of gas. I'm gonna shave half an inch off you and shape you like a bullet."
DriftKing is offline   Reply With Quote
Old 03-17-2011, 01:28 AM   #4
morris
CF Senior Member
 
Member Since: Feb 2005
Location: Germantown TN
Default

Get rid of it I want more of it
morris is offline   Reply With Quote
Old 03-17-2011, 01:46 AM   #5
ZL-1
CF Senior Member
 
ZL-1's Avatar
 
Member Since: Aug 2004
Location: IL / FL .
Default

And I thought I was the only one who hates all that popping and farting!

Factory exhaust systems were usually designed to eliminate those rude sounds. But Corvette designers attending Corvette events saw that many owners change to louder aftermarket systems and they actually seem to like all the popping on decel. So although earlier Corvette mufflers were tuned to be quiet on decel, the popping was not tuned out of NPP or the new Z06 system. On the original Z06 system the exhaust control module closed the bypass valves immediately when lifting off the accelerator. New designs starting with the 2008 NPP keep the valves open during decel to make more noise. Most owners seem to like the popping (kinda like most Harley owners like the loudest straight pipes possible), but you can't please everybody.

The popping is not caused by an external leak but by air and fuel not completely shut off. After several seconds of decel you can hear when the fuel does shut off and it gets quieter. I was able to eliminate the popping on an old carbureted 1980 Corvette that had stock 350 and straight pipes. The trick was to unseal the idle mixture screws and adjust them for max idle speed, then back off the idle set screw to close the throttle plates as much as possible for a low idle speed. While not EPA-friendly, this completely eliminated all the popping on decel. There's no such fix though for new fuel injected cars. The ECM keeps the idle speed high until you stop, contributing greatly to the popping.

I was able to reduce the popping a bit on my 2006 Z's B&B Fusion exhaust by adding a Dr Gas x-pipe. It gave it a nicer tone and tamed the popping to more reasonable level. But now the 2011 has an x-pipe from the factory. Even if you swapped mufflers with an earlier Z06 you still might have the popping because your module keeps the valves open when you lift.

Maybe you can get used to all the noise and be consoled by the fact that most Corvette owners think it sounds cool as hell...

.

Last edited by ZL-1; 03-17-2011 at 02:10 AM.
ZL-1 is offline   Reply With Quote
Old 03-17-2011, 02:00 AM   #6
DriftKing
CF Senior Member
 
DriftKing's Avatar
 
Member Since: Dec 2010
Location: Canton GA
Default

Quote:
Originally Posted by ZL-1 View Post
Maybe you can get used to all the noise and be consoled by the fact that most Corvette owners think it sounds cool as hell...
Agreed!
DriftKing is offline   Reply With Quote
Old 03-17-2011, 02:00 AM   #7
Bill Dearborn
Tech Contributor
 
Bill Dearborn's Avatar
 
Member Since: Oct 1999
Location: Charlotte (formerly Endicott, NY) NC
Default

Most car freaks love the sound of a good muffler that lets you hear the sound of a car backing down. The old Glass Packs were great once you shut off the ignition while coasting and then turned it back on so the fiberglass packing would burn/blow out. After that they could wake eveybody for 2 or 3 blocks with just one shot of the throttle and letting the car coast down while in gear.

Here you are trying to get rid of something that people worked hard to get.

Bill
Bill Dearborn is offline   Reply With Quote
Old 03-17-2011, 02:28 AM   #8
ZL-1
CF Senior Member
 
ZL-1's Avatar
 
Member Since: Aug 2004
Location: IL / FL .
Default

Quote:
Originally Posted by Bill Dearborn View Post
Most car freaks love the sound of a good muffler that lets you hear the sound of a car backing down. The old Glass Packs were great once you shut off the ignition while coasting and then turned it back on so the fiberglass packing would burn/blow out. After that they could wake eveybody for 2 or 3 blocks with just one shot of the throttle and letting the car coast down while in gear.

Here you are trying to get rid of something that people worked hard to get.

Bill
I loved the sound of old glasspacks and musclecars backing down too. But the great ones had a steady rap or buzz or roar when backing down, not at the erratic popping we hear from our modern cars.

BTW, we used to turn off the ignition while coasting too. It was a quick way to remove an old rusty exhaust system . The M80-like explosion would make oval mufflers round if it didn't split open the
seam
ZL-1 is offline   Reply With Quote
Old 03-17-2011, 05:06 AM   #9
foremaw
CF Senior Member
St. Jude Donor '08-'09-'10-'11-'12
Support Corvetteforum!
 
foremaw's Avatar
 
Member Since: May 2006
Location: Providence Forge, VA
Default

I would be sorely disappointed if I did not have it. Nothing sounds better than a V-8 coming down.
foremaw is offline   Reply With Quote
Old 03-17-2011, 05:43 AM   #10
PureSwank
CF Senior Member
 
PureSwank's Avatar
 
Member Since: Jul 2008
Location: Texas Texas
IIII_II_IIII_I-1
Default

Mine pops during shifting, sounds good.
PureSwank is offline   Reply With Quote
Old 03-17-2011, 06:57 AM   #11
BSSN
CF Senior Member
 
BSSN's Avatar
 
Member Since: Dec 2009
Location: Shreveport LA
Send a message via AIM to BSSN Send a message via Yahoo to BSSN
Default

Quote:
Originally Posted by JMB View Post
I've just purchased a 2011 Z06 and the only thing that drives me up the wall about this car is the hidious sounding popping coming from the exhaust when the car is decelerating in gear or between spirited shifts This sound reminds me of a cheap car with leaky header gaskets!

Are there moisture drain holes or something else that needs to be plugged on the head pipes to cure this? What is causing this? I've tried to do a search on this forum but came up empty handed.
It's a free-flowing exhaust. That popping is un-burned fuel igniting in the exhaust system and is completely normal, and totally sickhouse.
BSSN is offline   Reply With Quote
Old 03-17-2011, 07:17 AM   #12
Mopar Jimmy
CF Senior Member
St. Jude Donor '06
 
Mopar Jimmy's Avatar
 
Member Since: Apr 2001
Location: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
Default

Quote:
Originally Posted by foremaw View Post
I would be sorely disappointed if I did not have it. Nothing sounds better than a V-8 coming down.
Must like myself ABSOULTELY LOVE IT as it gives the Z a race car sound and makes it funner for most!

I mean the 06 through 10 guys pay big $ for an aggressive cat back system and my B&B Bullets do it a ton and its the best!

Your lucky the 11 Zs have more aggressive exhuast but then again maybe not b/c different strokes for different folks and you don't like it.

Here's a solution I would think. A TON Of Z owners 06 through 10 would swap you even for your complete exhaust system from behind the exhaust manifolds out the the tail pipes, and this will make your Z nice and quiet like a Cadillac. Honestly, that shoud SOLVE what you don't like and the older Z exhaust is MUCH MORE TAME sounding!
__________________
2006 Black C6 Z06, black powder coated rims, CAI; B&B Bullet Exhaust, and of course 427 Badges ; Mopar Jimmy is back with a daily driver 2008 Dodge Challenger, 450hp Hemi SRT8, runs 12.7s with bolt ons, & a mean, Ralleye Green, 1969 Plymouth Road Runner machine, 600hp 505 ci, black steel wheels & black fiberglass 6-pack lift off hood. Thanks and Praise to GOD!
Mopar Jimmy is offline   Reply With Quote
Old 03-17-2011, 07:26 AM   #13
AMGPilot
CF Senior Member
 
AMGPilot's Avatar
 
Member Since: Nov 2001
Location: Rowlett TX
Default

Trade it in on a Prius
__________________
AMGPilot
(Jack)

2014 Obsidian Black C63 AMG Coupe Edition 507
2013 Diamond White Metallic ML350 4Matic
2006 Black SLK55 AMG: SOLD
2007 Lemans Blue Z06 (EVIL Z): SOLD
Rowlett, Texas
AMGPilot is offline   Reply With Quote
Old 03-17-2011, 07:43 AM   #14
JMB
CF Senior Member
 
Member Since: Aug 2000
Location: Tacoma, WA USA
Default

Quote:
And I thought I was the only one who hates all that popping and farting!

Factory exhaust systems were usually designed to eliminate those rude sounds. But Corvette designers attending Corvette events saw that many owners change to louder aftermarket systems and they actually seem to like all the popping on decel. So although earlier Corvette mufflers were tuned to be quiet on decel, the popping was not tuned out of NPP or the new Z06 system. On the original Z06 system the exhaust control module closed the bypass valves immediately when lifting off the accelerator. New designs starting with the 2008 NPP keep the valves open during decel to make more noise. Most owners seem to like the popping (kinda like most Harley owners like the loudest straight pipes possible), but you can't please everybody.

The popping is not caused by an external leak but by air and fuel not completely shut off. After several seconds of decel you can hear when the fuel does shut off and it gets quieter. I was able to eliminate the popping on an old carbureted 1980 Corvette that had stock 350 and straight pipes. The trick was to unseal the idle mixture screws and adjust them for max idle speed, then back off the idle set screw to close the throttle plates as much as possible for a low idle speed. While not EPA-friendly, this completely eliminated all the popping on decel. There's no such fix though for new fuel injected cars. The ECM keeps the idle speed high until you stop, contributing greatly to the popping.

I was able to reduce the popping a bit on my 2006 Z's B&B Fusion exhaust by adding a Dr Gas x-pipe. It gave it a nicer tone and tamed the popping to more reasonable level. But now the 2011 has an x-pipe from the factory. Even if you swapped mufflers with an earlier Z06 you still might have the popping because your module keeps the valves open when you lift.

Maybe you can get used to all the noise and be consoled by the fact that most Corvette owners think it sounds cool as hell...
Thanks for the explanation and welcome to the minority it seems

Quote:
Here's a solution I would think. A TON Of Z owners 06 through 10 would swap you even for your complete exhaust system from behind the exhaust manifolds out the the tail pipes, and this will make your Z nice and quiet like a Cadillac. Honestly, that shoud SOLVE what you don't like and the older Z exhaust is MUCH MORE TAME sounding!
Guys, please don't get me wrong....I LOVE an aggressive sounding exhaust and that's why I pulled my fuse and I ONLY run the car with the mufflers open because it was too damn quiet! Afterall, I bought a performance car, not a Cadillac STS!

My disappointment stems from the fact that my '88 LS7 Monte Carlo SS has ZERO "popping" to the exhaust with this exact same motor installed and clearly sounds better than ANY Z06 that I have ever heard (aftermarket mufflers included) and after all of the "hype" about the ZR1 x-pipe and new ZR1 mufflers I just got my expectations too high and certainly didn't plan on listening to pop, pop, pop, that's all. Of course being able to rowing the SS through the gears with 4.10's around town and having headers on it probably helps and I actually have quiet "DynoMax Superflow" mufflers on it

Quote:
It's a free-flowing exhaust. That popping is un-burned fuel igniting in the exhaust system and is completely normal, and totally sickhouse.
Based on my LS7 Monte Carlo having headers, no cats and a 3-1/2" exhaust system, X-pipe and 3" tailpipes I would have to disagree that this (popping) is a characteristic of a "free flowing" exhaust system.

And for those of you that love the popping, more power to you....not passing judgement
JMB is offline   Reply With Quote
Old 03-17-2011, 08:07 AM   #15
BubbaDuss
CF Senior Member
 
BubbaDuss's Avatar
 
Member Since: Aug 2008
Location: Coral Springs Florida
Default

the GTO's and F-bodies have always done this also. It's in the tune for the LS engines. DFCO = Deceleration Fuel Cut Off, the purpose is to let some gas flow through the exhaust to keep the cats from overheating. it can be removed through tuning.

Many people don't like it, others do. and It becomes much more apparent when you do an exhaust swap. I loved it on my GTO with headers and a Borla. the Vette has it, but its still very silent.
BubbaDuss is offline   Reply With Quote
Old 03-17-2011, 08:09 AM   #16
BSSN
CF Senior Member
 
BSSN's Avatar
 
Member Since: Dec 2009
Location: Shreveport LA
Send a message via AIM to BSSN Send a message via Yahoo to BSSN
Default

Quote:
Originally Posted by BubbaDuss View Post
the GTO's and F-bodies have always done this also. It's in the tune for the LS engines. DFCO = Deceleration Fuel Cut Off, the purpose is to let some gas flow through the exhaust to keep the cats from overheating. it can be removed through tuning.

Many people don't like it, others do. and It becomes much more apparent when you do an exhaust swap. I loved it on my GTO with headers and a Borla. the Vette has it, but its still very silent.
I am very curious if this DFCO being tuned out is what heats exhaust valves up...
BSSN is offline   Reply With Quote
Old 03-17-2011, 08:11 AM   #17
Turbo T/A
CF Member
 
Turbo T/A's Avatar
 
Member Since: Sep 2010
Location: ottawa ontario
Default

Agreed....the popping sounds like total @$$. A smoother, toned exhaust is definetly a better sounding one IMO.

Will an x-pipe cure this?
Turbo T/A is offline   Reply With Quote
Old 03-17-2011, 08:14 AM   #18
JMB
CF Senior Member
 
Member Since: Aug 2000
Location: Tacoma, WA USA
Default

Quote:
Will an x-pipe cure this?
Nope! My car has the ZR1 x-pipe on it from the factory.
JMB is offline   Reply With Quote
Old 03-17-2011, 08:29 AM   #19
capevettes
CF Senior Member
 
capevettes's Avatar
 
Member Since: Oct 2004
Location: Cape Cod Mass.
Default

Quote:
Originally Posted by BSSN View Post
It's a free-flowing exhaust. That popping is un-burned fuel igniting in the exhaust system and is completely normal, and totally sickhouse.
Right on the money. I didn't like it that much years ago but have grown to enjoy it. I guess it's a mindset. Free flowing exhaust/mufflers is going to do this when you decelerate. It's all good
capevettes is online now   Reply With Quote
Old 03-17-2011, 09:16 AM   #20
reidry
CF Senior Member
 
reidry's Avatar
 
Member Since: Apr 2003
Default

You could revert to the earlier exhaust configuration. My 2009 Z06 didn't have the popping.

I love the sound of my ZR1 - the popping is a like a short drum solo in the middle of a great rock song.

Ryan
reidry is offline   Reply With Quote
Old 03-17-2011, 09:16 AM
 
Go Back   Corvette Forum > C6 Corvette, 2005 - 2013 > C6 Z06 Discussion
Reload this Page How do you get rid of the "exhaust popping" on deceleration?
 
 
 
Reply

Tags
amg, borla, c5, corvette, cut, decel, deceleration, dfco, exhaust, fuel, glass, muffler, off, packs, pop, popping


Thread Tools Search this Thread
Search this Thread:

Click for Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Vararam, is this normal? stp357 C6 Corvette General Discussion 19 07-06-2014 11:03 PM
Akrapovic Evo Titanium...Does it pop? iwantaz06now C6 Z06 Discussion 27 01-31-2014 05:24 PM
Air tube on Kooks headers crack. mountainbiker2 C5 Tech 7 05-13-2013 12:01 AM
popping and slight backfiring on deceleration JCOC C6 Corvette General Discussion 16 10-24-2012 07:15 AM
Popping sounds Kurgen C3 Tech/Performance 11 09-17-2012 10:32 AM


All times are GMT -4. The time now is 08:47 AM.


Emails & Password Backup

Search Engine Friendly URLs by vBSEO 3.5.2