Tuning out Deceleration Exhaust Popping

[Russell James]

You do add more fuel to get rid of the popping.

The strategy is to bring up the AFR ratio under those conditions back to a ratio that supports combustion. Once you get back to full combustion, in the chambers, on decel you don't get the popping in the exhaust. You also get a little worse mpgs. Also a bit more engine decel braking affect. Great for road racing, less use of the brakes entering corners.

In the factory tune they lean out decel so much, what ever fuel is there is not at the correct ratio for combustion. So it shoots out as raw fuel and when it get's near the oxygen near the end of the exhaust, pop pop.

I do a lot of tuning on performance Harleys, and they do the exact same thing. When you put a free flowing exhaust on a Harley, they pop like crazy between shifts and decel. In their tuning, Harley has a decel fuel table, and all you do is keep adding fuel to that table and when you hit the sweet spot for the engine combo/mods, it won't pop so much. It'll have more of a snarl between shifts instead of snap, crackle and pop.

[2010SSRS]

Originally Posted by Edrock

This is just a guess...but wouldn't tuning out the decel pop mean fuel would continue to flow during decel, therefore, no more popping? If this is the case, then the downside to tuning it out would be a tad bit worse gas mileage, correct? That's about the only negative I can think of.

you are 100% correct.

Originally Posted by Michael_Js

Hmmm...is that true? More fuel? I'm going to my dealer on Wed to have this tuned "down"...

doubt the dealer would.......could constitute voiding warranty cuz ur changing the stock tune.

Originally Posted by 1320junkie

I do not like refined muscle cars...heck I wish you could order a 5th gen without power steering, a/c and all of that other crap.

i'd love to see a COPO type version of the 5th Gen w/ a NON-SuperCharged LS7 or LS9 thug....

Originally Posted by litle88

I can't stand when grown men want to tune out or get rid of things that are a must on a CAMARO SS/RS. Remember SS stands for Stock Sucks. Lol

then don't look thru the forums...........it's 24" DUB's and chrome plated plastic everywhere!

[myold88]

Originally Posted by ffrcobra_65

LS3 normally make an exhaust popping and gurling sound during deceleration and the sound becomes even more noticeable and louder with an exhaust mod. I happen to like the noise but others find it annoying. The popping is caused by the DFCO (deceleration fuel cut off) and is a stock feature of the LS3 (maybe L99 as well?). Other than for sound suppresion, what are the benefits of tuning out the popping?

My L99 A6 makes the same popping sound on deceleration when in M/S mode. Have stock exhaust and only 2300 miles. I don't mind it at all but might have the dealer check it out during my first oil change in a few weeks.

[Bryan]

I think the popping on decel sounds great.

[litle88]

Originally Posted by Bryan

I think the popping on decel sounds great.

AMEN TO YOU BROTHA

[THUMPER20X]

Originally Posted by Danny Thomas

x3 These are muscle cars not pimp mobiles..whats with the 22's and bling bling

X4, thats why I went for the 1SS.

[Buelligun]

I chatted to a shop who do alot of tunes, as we were chatting I mentioned about the popping, he said "yeah we can tune that out easily" I turned round and said "hell no, it sounds way too cool!!"

[bnsmith78]

I love my Corsa Catback on my LS3 SS. Sometimes I hear a popping sound usually on deceleration (slowing down). It sounds cool, but is this ok.....?

[The 2010 Sin]

its an LS3.. learn to enjoy the popcorn experience.

[mikeSS]

i really love that sound... i try to make the most popping possible.. when i got down town its so loud, everyone looks

[SSizzle]

I have a Corsa Cat Back as well on a auto LS99. It will pop when you start it and under deceleration. I just put Kooks 1 7/8 long tube headers with high flow cats on it. You want to talk about sounding good!! It will wake it up and it's loud under acceleration! If you want more out of your exhaust get them. I found them on here from marylandspeed.

[blake2010ss]

to answer your question... yes its ok. its called deceleration fuel cut off... GM puts this on their cars for keeping mpg's higher. you can tune it out but it will cost you around 2 mpg avg.

[Ivan @ Southwest Speed]

Originally Posted by blake2010ss

to answer your question... yes its ok. its called deceleration fuel cut off... GM puts this on their cars for keeping mpg's higher. you can tune it out but it will cost you around 2 mpg avg.

Very good post. I like this post. A very good post.

LOL

Right on point and not a personal view.

Good job.
Ivan

[winston2ss]

I'm thinking of doing a muffler delete for now to save a few dollars. I just don't want alot of decel popping. I understand there will be some. I'm wondering if it's not as bad on the L99 as it is on the LS3. Anyone know for sure?