Digital Tuning 1991-exhaust crackles

paddyrk

Member
Jun 7, 2018
69
4
18
53
Dublin, OH
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.
 
  • Sponsors(?)


kendawg73

5 Year Member
Feb 5, 2014
466
118
64
47
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.
why on earth would you want the exhaust to pop and crackle?
 

kendawg73

5 Year Member
Feb 5, 2014
466
118
64
47
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.
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...
 
  • Agree
Reactions: General karthief

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
33,306
9,421
224
Massachusetts
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
69
4
18
53
Dublin, OH
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.
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.
 

kendawg73

5 Year Member
Feb 5, 2014
466
118
64
47
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.
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:
Thread starter Similar threads Forum Replies Date
5.0specialist 1991 5.0 Mustang Exhaust Concern Fox 5.0 Mustang Tech 8
D Fox 1991 Gt Exhaust 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 3
J 1991 Mustang LX Smell Fuel in Exhaust, Bogging down Fox 5.0 Mustang Tech 10
Q For Sale 1991 Hatch White/Blue Drag Spec, Near Full Build (Ohio) Fox Body Mustangs For Sale (1979-93) 1
M 65 headers (with a 1991 5.0) Classic Mustang Specific Tech 1
G 1991 mustang engine compartment restore 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 10
F Engine 1991 5.0 HO ignition problems. Fox 5.0 Mustang Tech 5
C Foxbody with no start issues Fox 5.0 Mustang Tech 5
R Paint and Body 1991 mustang ssp questions 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 18
3 Fuel pump not priming 1991 Gt mustang Fox 5.0 Mustang Tech 9
J 1991 GT just up and died while driving Fox 5.0 Mustang Tech 4
BAD91LX For Sale 1991 LX 5.0 hatch. $6,750 with 154700 miles Hurricane, Utah Fox Body Mustangs For Sale (1979-93) 0
R 1991 2.3 lx hatch The Welcome Wagon 2
S Electrical wiring diagram for neutral safety switch/backup lights on a 1991 5.0/aod Fox 5.0 Mustang Tech 1
A Suspension Question on Camber Kit for 1991 LX 5.0L Fox 5.0 Mustang Tech 2
LarsD SOLD 1991 LX hatch 5.0 (347/TKO) Elgin, Texas Fox Body Mustangs For Sale (1979-93) 2
T 1991 Mustang 2.3 Litre to 5.0 litre swap Fox 5.0 Mustang Tech 7
D Getting codes 998 and 122. 2.3L (N/A & Turbo) Tech 1
D Where is the Eec Relay? 2.3L (N/A & Turbo) Tech 7
D New to mustang world. Have a 91' lx 2.3l with problems. 2.3L (N/A & Turbo) Tech 8
MrPerfect2 Engine 1991 - What does a normal idle suppose to sound like on OEM 5.0 ? Fox 5.0 Mustang Tech 7
FastDriver SOLD 1991 5 spd 5.0 LX vert $5,000 Fox Body Mustangs For Sale (1979-93) 9
T Electrical Issues with 91 mustang with a 93 5.0 motor Fox 5.0 Mustang Tech 9
C 1991 Buc tag decoding 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 6
6 For Sale 1991 LX Convertible 5-speed for sale Fox Body Mustangs For Sale (1979-93) 1
I For Sale 1991 Gt Mini-tubbed street/strip roller Fox Body Mustangs For Sale (1979-93) 0
F 1991 LX Fuel sender swap question... 2.3L (N/A & Turbo) Tech 2
87_LX_5.0 New to me 1991 LX Convertible 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 3
P 1994 GT- 1991 TRW Pistons 1994 - 1995 Specific Tech 2
R Fuel 1991 5.0 Fuel Pump Noise Fox 5.0 Mustang Tech 0
X SOLD 1991 2.3 LX Coupe Fox Body Mustangs For Sale (1979-93) 0
L For Sale 1991-93 Ford Factory Pony 16 inch 4 lug rims/center caps and tires Wheels Tires Brakes 0
Fox904 Progress Thread 1991 Foxbody K Member Swap 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 38
Hudson N Anyone know what this does? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 7
9 Drivetrain 1991 lx 5.0 aod trans issue Fox 5.0 Mustang Tech 1
I Engine 1991 Please Help -No Start No Click Starter Problems Fox 5.0 Mustang Tech 15
Hudson N My 1991 keeps dying, help. Fox 5.0 Mustang Tech 12
P 1991 lx 5.0 Fox 5.0 Mustang Tech 12
W SOLD 1991 LX 5.0, Westchester NY, 20k miles Fox Body Mustangs For Sale (1979-93) 3
P Engine 1991 Smog Pump Question Fox 5.0 Mustang Tech 6
USCGunner Fox 1991 5.0 LX price 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 19
USCGunner Paint and Body 1991 Convertible window question Fox 5.0 Mustang Tech 6
B Electrical 1991 GT PCM Relay 4, 5 or six pins Fox 5.0 Mustang Tech 2
G Electrical 1991 LX Fox 5.0 Mustang Tech 0
T 1991 mustang builds The Welcome Wagon 1
S Electrical 1991 lx 2.3l convertible mustang 2.3L (N/A & Turbo) Tech 8
9 odd creaking noise Fox 5.0 Mustang Tech 3
C Engine 1991 mustang gt automatic Fox 5.0 Mustang Tech 21
Hudson N Fox Clicking/ticking sound coming from the front suspension 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 3
Hudson N Fox Alternator or smog pump is seized 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 7
Similar threads