Anyone who’s into cars, has seen a Fast and Furious movie, or has a soul knows that flames firing out of an exhaust pipe are very, very cool. Cars are powered by controlled explosions and the idea of those explosions going where they’re not supposed to without doing any real damage is psychologically pleasing. Maybe it’s because it makes us think that this car is right at the very limit of how powerful and raw it can be before it literally explodes. Who knows? What we do know, however, is why these flames of glory burst forth from exhaust pipes and how we can cause them to come out of our own cars (in certain circumstances). Read on to find out all about fire-breathing engines and how you can make your very own car shoot flames too.
Why Do Exhausts Shoot Flames?
Before we begin to talk about the various ways to make flames shoot from your car’s exhaust pipe we need to understand exactly why this wonderful phenomenon occurs. Internal combustion engines burn a combination of oxygen and gasoline which come from different sources. The throttle controls the amount of oxygen that gets allowed into the engine’s cylinders and the engine responds by releasing the right amount of gasoline (in vapor form) for proper combustion. When you’ve got your foot flat to the floor the engine is operating at full capacity. Much larger quantities of gasoline are dumped into the cylinders than at partial throttle and this is the fuel for excellent exhaust flames. Taking your foot off the gas quickly at full throttle abruptly shuts off the supply of oxygen while the fuel system is slower to react. The fuel in the cylinders, which now doesn’t have enough oxygen for a full burn, passes into the hot exhaust system (where there is more oxygen) and ignites. Just like that, your car is a flame-spitting dragon, much to the offence of old ladies and boring people everywhere. So what can you do to help this happen?
The first thing you’re going to want to do in the pursuit of fire-breathing perfection is ditch your car’s catalytic converters. These environmental killjoys serve to make sure anything exiting your car’s tailpipe is nice and burnt for the benefit of Johnny Polar Bear. They provide a blockage in the path of righteous fire and must be done away with. As an added benefit straight pipes will not only allow your car to spit fire but are also much, much louder than OEM exhausts with their silly emissions standards. It’s your car and it should behave like it!
Another extremely useful bit of kit for shooting exhaust flames is a carburetted engine. Fuel injection is a little too precise for this kind of hooliganism. Carburettors are classic and can really help your ride live up to its full flame-throwing potential. Their slower response times work extremely well with the full-to-no throttle method mentioned above. Get a powerful carburetted V8 and you’ll be barbequing the Prius behind you at the lights in no time.
Mess With the Air/Fuel Ratio
This tip is only for drivers who are really serious about shooting big flames from their exhausts. Take caution, because doing this incorrectly or for too long can have seriously negative effects on the health of your engine. We’ve all seen the videos of Aventadors burning to the ground in swanky neighborhoods. You don’t want your tuned-up rocket ship to go out the same way.
Basically, this involves playing with your car’s injectors so that they supply way more fuel than is needed for full combustion. Running rich like this will all but guarantee exhaust flames, but will also wreck your fuel economy and can cause your engine to run hot. Your ride will stink of unburnt gas, burn your eyes with its fumes, and make black smoke. If you’re still running catalytic converters they may become clogged up which will rob power and essentially choke everything upstream of them. Be careful if you do this and only do so if you know what you’re doing!
There’s another way to make your exhaust spit fire although this is only really for race cars. Turbocharged racing machines feature antilag systems which dump unburnt fuel into the exhaust manifold to maintain exhaust pressure and keep the turbo spooled up when the driver’s foot’s off the gas. If you put an antilag system on your road car, please send us a video.