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Digital Tuning 1991-exhaust crackles

  • Thread starter Thread starter paddyrk
  • Start date Start date Oct 9, 2018
  • Tags Tags
    347 347stroker bang crackle exhaust hp efi lx pop stroker

paddyrk

Member
Jun 7, 2018
71
5
18
Dublin, OH
Oct 9, 2018
#1
  • Oct 9, 2018
  • #1
Hello all,

I have a 1991 347 stroker lx 5.0 with the HP EFI system. I have an off-road X-pipe with shorty headers, full tail pipes, and mufflers. I would like to know how to do exhaust pops and crackles, such as when I let off the throttle after acceleration. I have not had any success with this so far, but if anybody has any information on how to do this, I would love to hear about it.
 
K

kendawg73

Well-Known Member
Feb 5, 2014
474
102
64
Oct 10, 2018
#2
  • Oct 10, 2018
  • #2
paddyrk said:
Hello all,

I have a 1991 347 stroker lx 5.0 with the HP EFI system. I have an off-road X-pipe with shorty headers, full tail pipes, and mufflers. I would like to know how to do exhaust pops and crackles, such as when I let off the throttle after acceleration. I have not had any success with this so far, but if anybody has any information on how to do this, I would love to hear about it.
Click to expand...

why on earth would you want the exhaust to pop and crackle?
 

paddyrk

Member
Jun 7, 2018
71
5
18
Dublin, OH
Oct 10, 2018
#3
  • Oct 10, 2018
  • #3
kendawg73 said:
why on earth would you want the exhaust to pop and crackle?
Click to expand...
It sounds nice
 
K

kendawg73

Well-Known Member
Feb 5, 2014
474
102
64
Oct 10, 2018
#4
  • Oct 10, 2018
  • #4
paddyrk said:
It sounds nice
Click to expand...

I hate that... makes me think there is an exhaust leak...
 

paddyrk

Member
Jun 7, 2018
71
5
18
Dublin, OH
Oct 10, 2018
#5
  • Oct 10, 2018
  • #5
kendawg73 said:
I hate that... makes me think there is an exhaust leak...
Click to expand...
I have had exhaust leaks multiple times before and also heard crackles and pops multiple times before, and can easily tel the difference, as they do not sound very similar.
 
K

kendawg73

Well-Known Member
Feb 5, 2014
474
102
64
Oct 10, 2018
#6
  • Oct 10, 2018
  • #6
paddyrk said:
I have had exhaust leaks multiple times before and also heard crackles and pops multiple times before, and can easily tel the difference, as they do not sound very similar.
Click to expand...

I put the Roush mufflers on my daughters 2011 and it does that... if you wind out the gears and got to shift to the next one, it will do the popping... I hate it... lol... I try my best not to make it do it....

I"m thinking it has something to do with the way the newer motors are I guess... since I don't recall the push rod 302's doing this... plus I don't really care for the sound the newer motor make any way... love the old school sound of the push rod motors...
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,249
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Oct 10, 2018
#7
  • Oct 10, 2018
  • #7
The crackle on decell is unburned fuel being ignited in the exhaust. It's also caused by exhaust leaks allowing o2 into the exhaust...which allows unburned fuel to ignite.

How to replicate it? Create and exhaust leak and/or set your fuel mixture a little rich.
 

paddyrk

Member
Jun 7, 2018
71
5
18
Dublin, OH
Oct 10, 2018
#8
  • Oct 10, 2018
  • #8
Mustang5L5 said:
The crackle on decell is unburned fuel being ignited in the exhaust. It's also caused by exhaust leaks allowing o2 into the exhaust...which allows unburned fuel to ignite.

How to replicate it? Create and exhaust leak and/or set your fuel mixture a little rich.
Click to expand...
Ah okay, that makes sense, so I would need to get some source of o2 into the exhaust without messing up my o2 sensor, as my ECU already runs it rich.
 
K

kendawg73

Well-Known Member
Feb 5, 2014
474
102
64
Oct 11, 2018
#9
  • Oct 11, 2018
  • #9
Mustang5L5 said:
The crackle on decell is unburned fuel being ignited in the exhaust. It's also caused by exhaust leaks allowing o2 into the exhaust...which allows unburned fuel to ignite.

How to replicate it? Create and exhaust leak and/or set your fuel mixture a little rich.
Click to expand...

Well in most cases, yes, but here are some examples... my daughters car (2011), has no exhaust leaks, and nothing else was done to it but remove stock mufflers (so car is not running rich) and install the Roush ones (btw one of the easiest damn installs I have done, since the mufflers are at the very back, 2 bolts on each, bamn done...) I think the more free flowing mufflers cause air to go back or something, or maybe the stock ones kinda muffle that popping...

example 2, my bike (v-twin cruzier) will do it on decel with the after market exhaust... (100% no leaks)... the way I got that to stop doing it, is adding fuel (richen it up)when the throttle is @ 0% and in the 2000-500 or 3000-500 rpm range (forget which, but when I'm off the throttle and engine breaking) but that stops the popping on decel.. again, it's the more free flowing exhaust that caused it, with the stock exhaust you never heard it...
 
Last edited: Oct 11, 2018
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