flame thrower

i got bored one day and decided it might be a fun idea to try to mkae my little purple sunfire throw flames form the exhaust. after playing around with it for awhile, i realized that this wasnt going to be as easy as it was on my old nova cause of my catalytic converter. so, while watching monster garage one day i saw them light up the exhaust using propane. now, obviously the spark plugs have to go after the end of the propane line, but doesnt the gas have to mix mix with the oxygen before it can ctach fire? if anyone can explain this better to me, please help

There should be enough oxygen in the exhaust to at least ignite the propane and support a modest burn. It won't be very hot or reliable, but as soon as it leaves the tailpipe it will give you the desired result.

If you're having trouble with not enough oxygen, drill a hole in the exhaust upstream of the propane, then point the drill bit (still in the hole) toward the back of the car. This will make a little reverse scoop that will pull a little air in as the exhaust rushes by.

And (although I'm sure you know this) your little addition could land you up to 30 days in jail since its a felony in almost every state. In some states even more since not only are you in possession of an illegal incindiary device, you constructed it yourself. Its like the difference between underaged possession of alcohol vs. underaged moonshining :)

o really, i didnt know that... hmm, mayeb this isnt such a great idea lol

The law is the same for Canada?
Sometimes in scoobys, when the pilot releases the gas pedal, A somewhat loud exploding sound is head at the tip of the exhaust and there is also some fire there, What causes this?
I don't know if thats right....
When we release the gas pedal, there are some unburnt gas which goes through the exhaust, Upon contact with ambiant air and the hot fuel mixture, this explosion occurs???
Does it has to do something with the decat pipe and ECU(contributes for the thing that happens above)?

The law is the same for Canada?
Sometimes in scoobys, when the pilot releases the gas pedal, A somewhat loud exploding sound is head at the tip of the exhaust and there is also some fire there, What causes this?
I don't know if thats right....
When we release the gas pedal, there are some unburnt gas which goes through the exhaust, Upon contact with ambiant air and the hot fuel mixture, this explosion occurs???
Does it has to do something with the decat pipe and ECU(contributes for the thing that happens above)?

Yup. Closing the throttle makes a momentary rich condition (not so much with EFI, but a little is to be expected). The hot air and unburnt fuel go boom when they leave the tailpipe.

Not sure about the canadian laws, but they crack down on it pretty hard here in the states. I went to a swap meet in Butler, PA and the cops were waiting to arrest anyone with even the slightest violation. They were pulling over darn near anything that wasn't stock. During the parade, a 46 DeSoto had a flame thrower... not even a propane one, just using his foot to richen the exhaust then kicking an auxiliary spark plug on and the cops got him leaving the event. Car impounded, he spent the night in jail (from what the papers said) and was fined several thousand dollars.

The letter of the law says a lot of things. Whether or not they're enforced is another thing altogether. Did you know that in PA, having sex is still illegal? That's why I moved. :)

i live in australia and the laws against this such modification to the exhaust, i would think, are the same...but bugger that.... i was wondering if i were to put a positive wire from the battery to a spark plug and earth the plug, should it create a spark?