miss firing system?

[Kashy]

I over heard two blokes talking about miss firing systems at the local rally comp. can anyone explain it to me ?

[Neutrino]

its an antilag system used in WRC cars.....it will lett unburn fuel and air ito the exaust manifold where it will ignite and spin the turbo very fast.....it will kill your turbo extremelly fast too.....

[andres_lcf]

Can u explain me about the miss firing system more in detail , i'm very interesting in it. If got picture is better for me to understand.

[xXRyCe_R0CkEtXx]

A misfiring system is actually called ALS(Anti Lag System). heres how it works:
When the driver lifts his foot from the gas pedal the ignition timing is altered with sometimes 40° or more of delay (retard) and the intake air and fuel supply mixture is made richer. The inlet butterfly is kept slightly open or an air injector is used to maintain air supply to the engine. This results in air/fuel mixture that keeps getting in the combustion chambers when the driver no longer accelerates. The ignition being delayed, the air/fuel mixture reaches the exhaust tubes mostly unburned. When the spark plug fires, the exhaust valve is starting to open due to the ignition delay mentioned above. Additionally, the exhaust temperature being extremely high, the unburned fuel explodes at the contact of the exhaust tubes. Luckily the turbo sits right there and the explosion keeps it turning (otherwise it would slow down since its intake, the exhaust gases, is cut-off). The effect is vastly lower response times with some downsides: A quick rise of the turbocharger's temperature (which jumps from ~800°C to the 1100°C+ region) whenever the system is activated. A huge stress on the exhaust manifold and pipes (mounted on a street car a bang-bang system would destroy the exhaust system within 50-100 km). and the turbo produces significant boost even at engine idle speeds Reduced engine brake When the driver lifts his foot from the gas pedal the ignition timing is altered with sometimes 40° or more of delay (retard) and the intake air and fuel supply mixture is made richer. The inlet butterfly is kept slightly open or an air injector is used to maintain air supply to the engine. This results in air/fuel mixture that keeps getting in the combustion chambers when the driver no longer accelerates. The ignition being delayed, the air/fuel mixture reaches the exhaust tubes mostly unburned. When the spark plug fires, the exhaust valve is starting to open due to the ignition delay mentioned above. Additionally, the exhaust temperature being extremely high, the unburned fuel explodes at the contact of the exhaust tubes. Luckily the turbo sits right there and the explosion keeps it turning (otherwise it would slow down since its intake, the exhaust gases, is cut-off). The effect is vastly lower response times with some downsides:A quick rise of the turbocharger's temperature (which jumps from ~800°C to the 1100°C+ region) whenever the system is activated. A huge stress on the exhaust manifold and pipes (mounted on a street car a bang-bang system would destroy the exhaust system within 50-100 km). The turbo produces significant boost even at engine idle speeds. Reduced engine brake. taken from www.rallycars.com .....couldn't have said it better myself....^_^

[xXRyCe_R0CkEtXx]

don't have a pic =/ sry

[andres_lcf]

Miss firing system need to installed the special part? example like, i want to built a turbo engine, so i installed a turbo kit to my engine. Is it the miss firing system is very powerful?? how powerful is it?

[andres_lcf]

Sorry, i still not so understand about what u are explain. I want to ask about the miss firing system is installed near where? The miss firing system is a performance parts? How the Miss firing system look like?? Please tell me!! Thanks to explain for me.

[xXRyCe_R0CkEtXx]

Ok...... for the misfiring system ill try to explain again..... 1st of all its called ALS(anti-lag system). To install it im not 100% sure but you put a chip in ur ecu... that does it. It's all with computers, you dont have to put any parts in the engine. But it would be a good idea to get maybe thicker exhaust pipes or ones that can handle alot of heat, unless you have the money to replace them all the time. The system wears out your exhaust pipes and turbo really quickly. Heres how it works: When ever you let go of the throttle....your turbo stops spinning....when you press the throttle again it needs time to spool up again...this is called turbo-lag. So ALS was created to eliminate turbo-lag. when you depress the throttle...your engine keeps injecting the air-fuel mixture into the chamber ...and the exhaust is open so the air-fuel mixture continues to the exhaust. Since the exhaust pipes are so hot the mixture explodes on impact creating enough force to keep the turbo spooling. It makes BANG noise because it is exploding outside the chamber, and you sometimes see flames when the mixture makes it further down the pipe. The system also works between shifts. It is only recommended for race/rally cars because they have the money and supply's to put in new exhausts an turbo's every race, but CAN be used on street cars...ive seen it...but im pretty sure it's illegal ^_^.

[xXRyCe_R0CkEtXx]

i dont have examples right now...ill look for some...but there IS a car in initial d - second stage that has one(if u've ever heard of it)^_^

[BeEfCaKe]

That would be the black evo III.

[SaabJohan]

ALS is basicly a function of the ECU, however if the car has a non electronic throttle some sort of air bypass must be used.

Some very powerful ALS used an air bypass directly into the exhaust manifold. The fuel could then be added by separate injectors or by the original injectors in the intake.

[andres_lcf]

Thanks for all!! i also have seen the Initial-D Evo III. i have seen this movie,so i want to know about the miss firing system. But i also have 1 more question, the Miss Firing system is just to put a chip into Ecu, so i want to ask the BANG soung, how ECU can make the BANG sound, or something happen that make the BANG sound. Please explain more in detail ...... Thanks to U all. Really very thank you.

[andres_lcf]

I still got 1 question, Is the miss firing system strong the ignition fire until the fire can came to the exhaust pipe? is it the fire burn the mixture of air- fuel in exploding outside the chamber? thanks

[SaabJohan]

The air/fuel is ignited late in the chamber or it can be self ignited by the high temperature in the exhaust manifold/turbine. Depends on how extreme you want to be.

The sound is just a pressure wave from when the air/fuel detonate.

[xXRyCe_R0CkEtXx]

yea....the sound is just it exploding outside of the chamber.