The fuel / air ratio is raised to make the mixed gas thicker, allowing more fuel to participate in the combustion. Therefore, when the oil is collected, there will be more unburned fuel emissions, and the phenomenon of fire is more likely to happen.
There are several cases of fire in the tail of a car.
The first, in a racing race, the bend is bound to slow down. But Turbo in the car after the oil, drop in engine speed, exhaust becomes small, will not be driven turbine, turbine speed decreased; stay out under acceleration, back to the oil, in order to promote the operation of turbine turbocharging, but turbine hysteresis will be very obvious, is to reduce the speed of the car. So some car factory invented the "partial ignition" technology, simply change the driving computer, turn in the oil collection, still to fuel sprayed into the cylinder, but does not make gasoline ignition, keep a fog, and then into the exhaust system, when the exhaust fog oil and gas mixed gas enters into the high temperature tube. It will detonate gas instantaneous expansion, turbine drive, high speed so as to maintain the turbine, to be re corner gas, then the minimum delay. This kind of fire can only happen when the car slows down.
The second, due to a part of the converted car, the use of straight line, the exhaust system is shorter, plus in order to increase the power, often increase the amount of fuel injection. When the engine speed is very high, the stronger oil and gas can not be completely burned out in the cylinder, then it will be discharged from the engine, then it will continue to explode and burn after the engine is discharged, so that we can see the flames in the exhaust pipe.
Third, this is purely for visual impact, in the middle of the exhaust pipe on a gasoline injector and ignition device, but also through the controller to control the car, so long as a button, when the engine idle speed can be up to two meters long pipe out of the flame in the exhaust.