CyrusA

I was watching some race videos and the cars shot flames out the exhaust. Someone explained that it helped spool the turbo. Can someone be a little more indepth on exactly what a misfire system is please. Thanks. Do all turbo's do that?

fly_S2K

I'd also like to know what a "misfire" system is. I've heard it in a few race videos as well as some car enthusiasts talk about it.

I can partially answer your question CyrusA, flames may shoot out of the exhaust due to rich a/f conditions. Unburnt fuel will now ignite due to exhaust temps.

BenR

EH?

Are we talking wasted spark or Anti-lag systems?

boxer6

I got this information from other forum:

Anti-Lag System also know as ALS:

When the driver lifts his foot from the gas pedal the ignition timing is altered with sometimes 40

fly_S2K

Thanks for the information

Hyper-X

That's pretty much the complete description for the system. It's an anti-lag system that was used in select Mitsubishi Evo rally cars, but rules dictating excessive noise levels pretty much got rid of using the bang-bang system in recent years.

Some high power tractors have been seen using this kind of system where air and fuel is sent to the exhaust manifold and ignited, spinning those huge turbos back up to speed. A normal car would blow itself to pieces shortly after engaging this system (don't even think about using tubular headers). An average turbo can't withstand that kind of punishment so obviously you'd need something more beefy. Since the exhaust manifold ignites A/F next to the turbo, EGT's would climb like crazy, oil and water cooling takes a beating, detonation becomes a serious issue with the rising temps and such. Emissions control isn't possible as it would murder the cat beyond use.

I've actually had the chance to hear such a system a while back (not at close range) however it kind of sounds like an artillary simulator with a slightly higher pitch (ask any Army infantryman about what that sounds like) coming out of a car. It doesn't sound like your ordinary backfire.

shaolin

the correct spark plug air gap is essential to achieve optimum engine performance and long plug life. a gap that is too wide requires higher voltage to jump the gap. if the required voltage is greater than what is available, the result is MISFIRING. misfiring results from the inability of the ignition to jump the gap or the inability to maintain the spark. on the other hand, a gap that is too narrow requires lower voltage, which leads to rough idle and prematurely burned electrodes, due to higher current flow. so always set it according to manufacturer spec.

Hyper-X

LOL...

Shaolin, that was a nice explanation... however the thread's topic is about a Misfiring System, also known as an Anti-Lag system deployed on a few rally cars, not what a misfire is. Some refer to this as the Bang-Bang system due to the end result.

Zonie

YIKES! That sounds an AWFUL LOT like an afterburner on a jet engine... no?

AusS2000

Do Indy cars have this system?

When they accelerate after a corner there are several loud cracking sounds. I guess they could be the blow off valve, but they are very loud.