When i rev the car in neutral, the car makes a gurling noise from the muffler as the car is winding back down. What exactly causes this?

 

I donno, but I like it!

 

i would like it more if i knew it was completly normal and what it was. [sm=sigh.gif]

 

Yea i dunno what it is either but i love the noise almost everyone but people with stock v6 muffler has it...i think

 

I got it too, is it back pressure?

 

dont quote me but i beleive its the unburnt fuel that creates that sound....the new 4.6's dont really have as much as i like..it sounds great on the 5.0's with flowmasters when you downshift into 2nd or first...ive got slp loudmouths and you can hear it pretty good but these cars dont do it that well due to the computer which is actually pretty fuel efficient and doesnt start to engine brake for about 7 seconds....on most cars when you let off the gas you'll hear it right away as the cars momentum is pulling on the engine.......listen to any 5.0 with flows and o/r H and youll notive its normal and turns heads.....

 

my stock muffler on the 4.0 have a very clear gurgle, and now my gt take off has one as well, very noticable. Is this a bad thing?

 

No it's normal, its the backpressure created by unburnt fuel as stated above. It's nothing to worry about, besides it sounds so badass, especially when the engine hasn't warmed up yet.

 

I posted this same question on AFM - look for the response from 65sohc, he knows what he's talking about:

http://www.allfordmustangs.com/forum...ad.php?t=62177

 

i don't think its unburnt fuel; i think its temperature equalization within the pipes. or something like that. either way, its normal, and i freakin love it.


the crackling after revving at startup, now thats unburnt fuel.