What causes backfiring?

[Jahred]

Bandit, I hate to ask, but what is an "air pump" as you reference it???

I think this converstation about backfiring is very interesting. I am not sure we are getting anywhere, but I think there are some useful answers out there if we work at it.

My Exhaust system consists of nothing more than some custom made headers, and some pretty lightweight steel sidepipes........no mufflers, no cats anywhere here.

So it makes sense to me that there would be backfiring - which I think is a misnormer - at the exit end of the tailpipe.

When I ran with the Porsche club (not in cobra), a few of the really high end cars (prob also in the 600 HP range) would exhibit exhaust flames near the end of the first straight, which is nice and long........nearly a mile.

If the pipes are hot, and all the gas is not burned (I run a Holley 1000 HP)....and those hot fumes hit fresh cool air on the exit end of the pipe, BAMMMMMM!.....

I still think that's natural....but it is not a traditional backfire.....though I don't know what else to call it......

All that said, I would certainly believe that everything else being equal, no backfire would mean better fuel burn, better mileage, more power etc. And as I see my car now backfiring more prevalenting on the passenger side..........I do have to wonder...........Wasssuppp?? Something is slightly amiss, at best.

Question: What is a backfire? Is it a backfire if it is at rear of exhaust??

Question: Is anybody out there running a 514 with 1000 or greater carburation and straight pipes without getting some crackling and bangin when they back the car down from higher revs???????

I kinda like it, but it is hard on the ears and wanna make sure she is runnin right...........