free flow exhaust with reducing bends
When the driver let's off the gas pedal going into a turn raw fuel gets pumped into the exhaust manifold. The manifold is so hot the fuel ignites and you see flames from the exhaust pipe. It's totally normal.
Flames coming out the exhaust is the result of the exhaust igniting fuel that was not burned inside the engine. Occasional pops of flame can be from backfiring, which shoots out unbirned gas that gets ignited from the heat of the exhaust. On cars without electroinc ignition or fuel injection, which covers all older cars, turning the ignition off while moving and then back on can result in a backfire and flames.
i had a fuel leak
1980
I dirt track race and mine did it once it was because it was running to lean.
old junky exhaust systems have a lot of debris that catchs fire with high exhaust temperatures
I sat in my car in the driveway with the car idling, waiting for the kids to come out.
Oversized exhaust, headers and/or different mufler.
Flames shooting out of race car exhaust pipes is caused by unused fuel passing from the cylinder into the exhaust system and lighting by the heat of the exhaust. Race cars run a different grade of fuel than a normal passenger car so this is common. You have to really soop up a normal car engine for this to happen on a normal car.
it will make a puff puff sound while idling.
exhaust leak or a possible fuel line leak