Do Flowmasters hurt performance?

[mjh78]

The previosu owner of my car had some aftermarket mufflers welded in. Everything is stock I'm sure. I would think these are probably flowmaster mufflers. They do sound really good, but if I get the RPMs up to 3 or so and cruise to a stop...a lot of popping from the exhaust. Is this an indication of too much backpressure or something? Are these things robbing me of some power?

 

[Spro]

Pretty much normal to hear them pop and no they arent robbing power.

 

[M.P. Cobra Fan]

+1

No problems at all. That is just how flows sound. Personally I love the sound.

 

[SVT32VDOHC]

I didn't have any popping at all with my Flowmasters. I have had 11 or 12 Mustangs, most having flows, never had popping.

 

[fobra559]

I have flows and like the above posts, I have no popping sound nor do they rob power.

 

[2000fordstanggt]

my girl "pops" mostly when cold and slowing down in gear. hardly at all once shes warmed up though.

 

[Mossberg]

No popping with my Flows either.

 

[M.P. Cobra Fan]

Every car I have had that has had flows has had a popping when I came off high RPM's or downshifted.

 

[BlackGT4.6]

if it pops like that it has an exhaust leak. The popping is the exhaust sucking in air and then it explodes.

 

[2000fordstanggt]

i know 100% that i do not have an exhaust leak though. how bout you m.p.?

 

[BurningRubber]

With an offroad mid pipe it can/will pop, even sometimes with a catted mid pipe it can pop on deceleration.

An exhaust leak on deceleration would sound more like a hiss or air being sucked into something.

 

[2000fordstanggt]

With an offroad mid pipe it can/will pop, even sometimes with a catted mid pipe it can pop on deceleration.

An exhaust leak on deceleration would sound more like a hiss or air being sucked into something.

right, when i first bought the car it had a stud broke off the exhaust manifold and it sounded...embarrassing. now i hear something rattle near the back right around 2k rpm. where are the heat shields?

 

[georgio440]

My Magnaflows do it. I personally love the crackling/popping. My old Dakota did it, too.

 

[[BlackDiamond]]

Mine only pops if I disconnect the IAT connection on the intake, maybe yours is disconnected?

 

[eliteJAE]

i have flows and i get that throaty popping sound when i engine brake or decelerate, seems normal, other mustang at school does the same, no exhaust leaks on his for sure.

 

[GTtopLESS]

I have catted X with Flow 50 series cat- also have slight crackle when letting rpms rev down. I think it sounds tight

 

[lazerred02]

right, when i first bought the car it had a stud broke off the exhaust manifold and it sounded...embarrassing. now i hear something rattle near the back right around 2k rpm. where are the heat shields?

I sometimes hear that rattle around 2k also, I checked all my exhaust connections. They were all tight and no leaks, thats weird how it just happens right at 2k and thats it.

 

[M.P. Cobra Fan]

i know 100% that i do not have an exhaust leak though. how bout you m.p.?

No exhaust leaks here!

 

[04GTMustang]

my guess would be if other peoples flows are not popping u might have an exhaust leak somewhere. I know ive got a leak somewhere with my exhaust i think its where my xpipe connects to the manifold. but i have a sort of rattle sound around 2k and under when im hitting the gas. its not a ping type rattle. and it pops on decel but im pretty sure all borlas pop a good bit on decel lol.

i would check everything again something may not be lined up properly and ur just not seeing it.

 

[Twista]

when i had flows the ONLY.. i mean ONLY time they popped is when i did something stupid.

Thats:

Revving the engine up in gear while driving when the engine was cold as ****. As the revs would drop the flows would POP like pop corn REALLY REALLY REALLY loud. didnt do that much and yes its bad for the engine, but thats the only time it would POP like that.