We've all seen it whether in movies at car shows and race tracks or from the Lamborghini passing you on the highway , flexing its wildly loud V 12 engine flames bursting from a tailpipe .
It's exciting , loud and sometimes even scary .
This phenomenon known as after fire doesn't happen to your average car in a combustion engine vaporized fuel and oxygen are mixed together and ignited .
These contained explosions drive the engine to rotate and get the wheels spinning , but sometimes not all of that fuel gets burned up .
If the fuel travels into the hot exhaust pipes and gets the chance to meet the oxygen outside , it ignites in a burst of fire when it comes out of the tailpipe .
This doesn't happen in your typical front engine passenger car .
Their engines are smaller and low powered , requiring far less fuel to function .
They also have more extensive exhaust systems for the fuel to travel through before reaching the tailpipe making it harder for them to get hot enough to cause after fire .
And their exhausts feature catalytic converters devices that clean up pollutants like excess fuel vapor to make for cleaner emissions .
But a Lamborghini with a 12 cylinder engine at the back of the car only needs a short exhaust that's piping hot from emitting 760 horsepower worth of combustion gasses .
Its catalytic converter barely has a chance to be effective before the extra fuel ignites .
However , those bursts of flames are just as possible with smaller turbocharged engines , particularly ones with anti lag systems found on race cars and tuner cars , anti lag is a system designed to overcome the acceleration limits of turbo chargers .
Turbo chargers give cars an extra boost by sucking compressed air into the engine .
Everyone knows fire requires oxygen .
So this makes for better combustion and a more powerful engine .
Turbo chargers are driven by the car's exhaust gasses .
These gasses wind a turbine connected to an impeller that begins to draw in air , taking your foot off the throttle , causes the exhaust gasses to halt and your turbo charger to stop spinning .
Once you put your foot back on the throttle , that extra time it takes to get the turbo back into boost mode is known as lag .
Anti lag involves programming your engine to create a delayed smaller ignition .
The delayed spark not only allows more fuel to enter the cylinders but causes combustion to occur as late as possible .
This fuel heavy mixture continues igniting outside the cylinder and into the exhaust manifold where the turbine is the heat of the exhaust causes it to keep combusting and spooling up the turbine .
So your engine receives a constant boost .
The flames from that combustion outside the engine come out of your tailpipe .
A third source of exhaust flames are two step rev limiters .
You may know them on consumer cars as launch control systems .
Essentially , the car is programmed to limit how fast the engine spins to maximize acceleration while preventing you from blowing out your engine .
With the first rev limiter , the computer tells the engine to hold it a certain R PM that it thinks is best for launch .
This is designed to minimize your wheels from spinning too much .
Give your tires as much grip as possible and get you moving down the road quickly from a stop .
The second rev limiter sits near the engine's red line .
The maximum engine speed that an internal combustion engine is designed to operate without causing damage to internal parts due to safety and emissions laws .
Factory launch control systems limit the engine's R PM by adjusting the air fuel mixture to be leaner on fuel .
But aftermarket solutions simply delay or cut its ignition .
But where does the un burned fuel go ?
You guessed it if you're thinking about modifying your car ?
So it spits fire .
Beware in most states , vehicles that have been moded to shoot flames can result in a ticket on public roads unless your big engine supercar can't help it .
Remember that flaming exhausts are best reserved for car shows , meet and greets and the race tracks .