Backfiring after exhaust work done.

T

twokingsracer

New Member

Oct 29, 2002

34

0

0

Joplin, Mo.

Sep 27, 2003

#1

• Sep 27, 2003

• #1

I recently had an O/R H pipe and dumps put on. I am running Flowmaster Series 40's. The car sounds really great but I have now gotten a backfire when shifting during a race. I did not have this before the install. I got under the car and found where the dumps are not completely welded to the mufflers at the top. I have been told by a couple of people that the dumps not being completely welded are causing the backfire. I have also been told that Flows will tend to backfire when dumps are put on. Is it that I am sucking cold air in during those high RPM shifts? These are the mods I have so that you have a better picture of what I am running. Thanks for any help.

1997 Mustang GT 4.6L 2V
C&L 80MM MAF w/True Flow inlet pipe
K&N Air Filter with fender relocation
MAC 70MM TB
Superchip with mail order tune
MAC O/R H pipe w/dumps and Flowmaster Series 40's
4.10 gears
Granatelli Solid Upper and Lower Control arms
B&M Ripper Shifter

Parts I have that are going on this week:
PI Cams
Aluminum U/D Pullies
Steeda full length SFC's
Battery relocation kit

 

6

68's Revenge

New Member

Sep 19, 2003

9

0

0

Albuquerqe, NM

Sep 27, 2003

#2

• Sep 27, 2003

• #2

Fresh air hitting too rich exhaust wil cause a pooping in the exhaust, I would look at tuning, does your car have asmog pump?

 

T

twokingsracer

New Member

Oct 29, 2002

34

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0

Joplin, Mo.

Sep 28, 2003

#3

• Sep 28, 2003

• #3

Its a 97. I dont think so. But I dont know. Anyone...anyone.

 

9

97rioreddohc

Member

Jun 30, 2003

220

0

16

San Antonio, Tx

Sep 28, 2003

#4

• Sep 28, 2003

• #4

Thats happened to me many times and still does, after installing the o/r x pipe, its a caused by a rich condition and it seems to only happen when the weather is cold or when the car is extremely cold

 

1fast03pony

Member

Jul 1, 2003

749

0

17

New york

Sep 28, 2003

#5

• Sep 28, 2003

• #5

its normal. its a free-er flowing exhaust. my fathers c5 backfires like a mutha and it was just dynotuned. hes running a corsca indy cat back and magnaflow o/r x.

if its too much then i suggest switching exhausts it might be the way your catback routs the exhaust.

 

2k2SilverBullet

Founding Member

Jul 30, 2002

356

0

0

Missouri

Sep 28, 2003

#6

• Sep 28, 2003

• #6

i would worry about it,my friend had the same problem with his flows dumped, hopefully i will see you oct. 3 at mokan

attila

 

2k2SilverBullet

Founding Member

Jul 30, 2002

356

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0

Missouri

Sep 28, 2003

#7

• Sep 28, 2003

• #7

i meant i wouldnt worry about

 

J

Jr2fast

Founding Member

Aug 22, 2002

1,097

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0

Mannford, OK

Sep 29, 2003

#8

• Sep 29, 2003

• #8

its the exhaust mine started it when I put the O/R on then the flows made it worse and I dumped mine last week. Its nothing, just tell them your motor i smaking so much power its bursting out the exhaust

 

87PonyBoyGT

New Member

Sep 5, 2003

24

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0

north jersey

Mar 30, 2004

#9

• Mar 30, 2004

• #9

68's Revenge said:

Fresh air hitting too rich exhaust wil cause a pooping in the exhaust, I would look at tuning, does your car have asmog pump?

Click to expand...

im curious what does the smog pump have to do with the popping because iim having similar problemos. i have bbk unequals with a mac xpipe and american thunder flows. i know i have an exhaust leak and was told that was causing the backfireing. but how does the smog pump play a role in this?

 

shawnster

New Member

May 17, 2003

78

0

0

Akron, Ohio

Apr 5, 2004

#10

• Apr 5, 2004

• #10

If you watch the movie "Bullett" when Steve Mcqueen is chasing the black Charger, His car is backfiring between gears too and I was told, when that movie was made that was a brand new 68 Mustang..so I would think thats normal..personally, I'm running Flowmasters American Thunders dumped and mine don't backfire..I guess it depends on the car..

 

streetstang03

unModerator

Dec 27, 2003

0

1

0

the dark side of the moon/home of the 1999, 2003,

Apr 5, 2004

#11

• Apr 5, 2004

• #11

shawnster said:

If you watch the movie "Bullett" when Steve Mcqueen is chasing the black Charger, His car is backfiring between gears too and I was told, when that movie was made that was a brand new 68 Mustang..so I would think thats normal..personally, I'm running Flowmasters American Thunders dumped and mine don't backfire..I guess it depends on the car..

Click to expand...

THe sound of McQueens 68 was a GT40, not the fastback. They layed the audio track of a GT40 over it.

 

shawnster

New Member

May 17, 2003

78

0

0

Akron, Ohio

Apr 5, 2004

#12

• Apr 5, 2004

• #12

Really? That would be a cool trivia question..did they do that to the charger too? I think that car had a 440 but Im not sure

 

doogz

Founding Member

Apr 11, 2002

760

0

0

London, UK

Apr 5, 2004

#13

• Apr 5, 2004

• #13

My offroad h-pipe + flowmasters began popping extremely loud at high-rpm quick shifts. If I powershift, it won't backfire and if I take my time getting back into it after a high-rpm upshift, it won't backfire either. I don't think putting the tailpipes helped any if I remember correctly. I'll see if the longtubes made a difference with the popping.