When I am driving maybe 75mph and let off the gas and begin to brake, it sounds as though my exhaust is "stuck" in the muffler and all of a sudden I can hear it coming out like a loogy? It slows me down too kind of like an exhaust brake. And when that pressure is released, the truck looses the exhaust brake feeling and coasts.

I have a 5.3L with intake and exhaust (50 series two chamber w/ turndowns after the muffler)The intake and exhaust are the only things I can reason that may play a part in this, so other mods have been left out <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

Do you have 4.10's and/or short tires? It sounds more like a side effect or a low gear ratio, or maybe there is something wrong with the transmission. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

 

naw just 3.73s out back and a TransGo shift kit wheel and tire combo is stock diameter. It happened pretty much after i cut my tail pipes to make room for rearend travel when i dropped the truck. I added some turn-downs after the muffler and lessened the problem, but it is still there.
Could it be atmospheric pressure? I thought i heard somewhere that 6" of tailpipe should be minimum b/c of atmospheric pressure pushing the exhaust back into the muffler? As to if this is true or if this is the problem <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> it's strange

 

my truck does it too i do not think it is any thing to worry about.
Ryan

 

my truck does it too... could it be a flowmaster thing... this is the second truck i have with flowmasters and they both did the same thing. I didn't think anything of it... and I never had any problems with my previous one.

 

cool i'm not alone. Ya, I haven't really noticed any bad side effects because of this. I get this picture in my mind though of exhaust building back all the way up to the cylinders and not being able to flow out of the head. It really isn't as bad as that visual seems though and I think it just mostly gets "stuck" in the muffler (so maybe it is just a Flowmaster thing) <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Thanks for the responses <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />

 

get some headers to free up some breathin
and continue to build up to the lightning killing machine we all dream of
happy hunting
mike
<img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

 

i've been wonderin why my flow does this aswell.

mine does it from about 2k to 1.5k
btw mine is 3in from the y to a 3in/out 40 series

 

OK I know what you mean now. It is normal. Not just Flowmaster. I had straight pipes and it did it loud, like a gunshot. I got a chamber "Flowmaster style" muffler and it does it still just not as loud. I think the only way to eliminate it is to put a big *** restrictive muffler on there.