correct. Its not fun around a college town, without making drunk people piss their pants when they see/ hear a loud bang.

 

lol. my brother's car used to do it pretty consistently at 1500rpm as well. tightened his blow off valve spring a tad (it still vents to atmosphere), cleared it up nice. still pops, but theres no more midget firing squads living in his invidia exhaust canister

 

to much unburned fuel causes flames to come out the exhaust, that is how they make those flame thrower shits that go out ur exhaust. they basically send shitloads of fuel thru, it catches fire, and doesnt burn all the way, goes out the exhaust....u should get a fuel pressure regulator, or if u have one, lower it down some...then let me know if it worked

 

he knows "why" the flames come out.... he is basing his question on the fact that everyone knows the 1,500 rpm backfire... the question is why doesn't his car do it anymore at 1500 rpm...

 

did he change or adjust his blowoff valve?

 

wonder if the colder weather (hell youre in tally as well so its even colder then down here near tampa), being denser and all, has leaned out your a/f a tad, or enough on deceleration to cause the backfiring to stop for now???