I have read multiple threads on backfiring and everyone says its normal for Rx7's
I have driven my car for 7000k and I have had nothing close to a backfire but now that I installed a walbro fuel pump and have taken off of my air pump it sounds like a gunshot if I shift at 3k...
My exhaust WAS missing a gasket but now I have installed a new one...
Id say backfiring ISNT normal...

 

it's pretty normal when you have free flowing exhaust and no emissions. When i do wot runs and let off my car shoot multiple flames kinda fun when racing people.

 

remember 87rx7tii that you installed a walbro meaning your running a little richer and if you took out the airpump im expecting you have no cats? so that means the excess fuel that gets throw out threw the exhaust get lit causeing backfire its very normal my 87 TII does it all the time im used to it only thing is that when around cops you gotta becareful....
TwEaK

 

the walboro pump is putting too much fuel in. Without something to control that fuel you are pumping essentially unburnt fuel into your exhuast which is igniting while in your exhaust. Kinda cool isn't it?

 

BINGO, we have a winner!!!

 

its amazing how people automatically make assumptions that ITS not normal for something to do something when like 85% of the rx7 owners cars backfire.....
TwEaK

 

I experienced more backfires by just putting a K&N drop filter in. At every shift, and when ever I was at WOT and let down, or was downshifting. EVERY SINGLE TIME. Was cool, just nice little ones, and some were really really loud.

You probably need to adjust some air flow, to compensate for the extra fuel you are putting in. That might minimize some of the backfires, but you will still experience them at every shift most likely.

 

My car doesn't backfire but it kinda pops when I down shift. I have straigth through exhaust on my N/A. I don't know if it shoots flames because I don't drive behind it.

 

my car does about the same thing. but it only does it in 2 places in the RPM band. when i shift around 7k or when the RPMs are dropping from 3k-2k and im not touching the gas. if im on the gas its not a problem though.

 

even in neutral ill rev to 6k, or get of the gas quick when giving it a spurt, and mine will blow 1.5m long yellow flames No cat and a single 3inch turbo back zorst

i wouldnt have it any other way

 

it doesnt mater what kind of fc you own it backfires if your still stock than you cant hear it couse of your cats but it stills backfires. since you put on a walbro pump id get straight thru mufflers otherwise your gonna burn any other kind.

 

mmm, i dont even think of mine as backfiring anymore, when i shift at redline and hear that sexy loud crack followed with flames, it cant be sweeter

 

I love it when people come up to me and say "theres something wrong with your car theres fire coming out of it"

 

yeah, my car does the same thing, and it got 10 times worse (or better) when I put my new bov on it. it's getting to the point where sometimes if I see a cop ahead I turn onto back roads and go around him :-P

 

how come mine doesnt backffire?

i have a walbro, a bov, 720cc injectors with no safc yet, and no emmissions with a straight exhaust to my 2 free flowing mufflers. and my car never shoots flames, i want flames, haha

 

My FC doesn't shoot flames... yet. This weekend, the cats are going.

 

can uyou shoot flames w/ a bonez highflow cat? cuz ive ran my car w/ open hedders b4 i got my superflow and DAMN i pulled into my school parkinglot and ppl scattered cuz they thought my car was on fire. it was GREAT!!

 

"how come mine doesnt backffire?
i have a walbro, a bov, 720cc injectors with no safc yet, and no emmissions with a straight exhaust to my 2 free flowing mufflers. and my car never shoots flames, i want flames, haha"

I am running close to the same setup and mine didnt either... not until I stuck in that fuel pump...

I dont want people diving for cover everytime I drive by...
I made an old guy fall on his ***. when I drove by last night...
he was gardening and im sure I shaved 5 years of his life....

 

HAHAHAHA, that's hilarious. I make my exhaust pop when people are tailing me on the highway. At night you can see their faces light up in your rear-view mirror. It gets them off your car pretty fast. But yeah, just get a S-AFC and you can tune it down so that you don't get it as often.