For those who watch Initial D, you will know what I'm talking about, for those that don't you still can help... anyways, I was watching Initial D Stage 2, and when Takumi raced Kyouchi from the Emperor team (all the Lancers), Kyouchi used a 'misfiring' system on his Lancer Evo III, which misfires the engine on purpose, and supposedly this reduces turbo lag or something? Is this true? can it be done in real life, or is this bad for the engine???

I'm not really sure how to describe it more technically, for those who watch Init. D perhaps you can explain this situation in more clearer terms so other people can comment on it....

Sounds a LOT like the JWT drag launch program for turbo cars. :D

IIRC...it pulls timing/fuel from one cylinder when activated. That creates a load on the engine....which is what causes the turbocharger to spool up.

Nice for boost-on launches at the dragstrip.

Somebody please correct me if I got the details wrong about the JWT drag launch program (Louis, I know you know more about this than do I).

The mis-firing system is used in WRC cars. Its purposely setup to keep turbo spooling so that they have power on hand but Im not familiar with the method, I beleive its extra fuel thats dumped in thats why most of those cars have fire spitting out of the exhaust. Systems like motec, autronics ,and ect offer this capabilities. But it will kill the turbo within a year or so.

I have not watched Initial D, but I believe what you are describing is much like the anti-lag system used in Rally cars. It injects raw fuel into the turbine. It makes a loud pop and sprays flames out the back when this is done. Much like an afterburner on a jet fighter. The turbos need a rebuild after every race, sometimes they fail after a of few stages too. Not a good thing for a street car unless you are Bill Gates.

yes yes this is exactly, flames shoot outta the exhaust .... see tv can be educational :) so i guess the general consensus is this is terrible for your turbo.. shucks, it sounded like fun... is there ever a 'safe way' to shoot flames out of the exhaust (just for the awww factor if i wanted to try hehhe)?

Originally posted by UcLaGeE
yes yes this is exactly, flames shoot outta the exhaust .... see tv can be educational :) so i guess the general consensus is this is terrible for your turbo.. shucks, it sounded like fun... is there ever a 'safe way' to shoot flames out of the exhaust (just for the awww factor if i wanted to try hehhe)?

Buy a S-AFC and play with it for a while. If your exhaust gas is rich enough, it'll ignite as it escapes the tailpipe.

I can explain this one. Rally cars use anti-lag systems (aka "bangbang", and some other terms) to keep large turbos spooled when off the throttle. Rally cars in particular utilize anti-lag more often than other motorsports because they must run a very small restrictor, and therefore do everything they can to maximize volumetric efficiency all across the board. To make a lot of power through a small opening, they run relatively large turbos for their high flow, but this isn't the best thing in a sport where you are constantly on and off the gas because big turbos are usually laggy. In rallying you need the power to be very responsive and available at a broad range of rpms. To allow the use of large, efficient turbos and still have good power without lag, rally teams use anti-lag. Although there is more than one scheme for doing this, the most common type is functionally a little different than the JWT drag launch program. Anti-lag usually works like this: When switched on, the ECU monitors throttle position (not clutch input) and watches for a throttle position below a certain level (say, 60%, 30%?) . When it sees this, the ecu increases injector pulsewidth to dump some extra fuel and retards the crap out of ignition timing (like 40 degrees!).. Some systems that use fly-by-wire throttle also keep the throttle open partially. The result is this: A bunch of fuel gets dumped into the cylinder, but because the ignition timing is so retarded, it generally doesn't get burnt, or if it does, its not until very late. The exhaust valves open now, expelling unburnt fuel into the hot exhaust manifold (the spark plugs have fired sometime by now). The fuel combusts between the head and the turbo, thus keeping it spinning, and keeping Mr. Rally driver happily on boost even after a couple of downshifts. The reason this is not very practical becomes apparent when you think about what is actually happening: the combustion phase of the engine's cycle is occuring OUTSIDE the engine block! The big explosion of fuel is happening in the exhaust manifold and crashing into the turbine blades, leading to turbo failure and cracked manifolds. Not a big deal to a factory backed rally team that can replace these things every other race, but not such a good idea on anything resembling a street car. I think I've got the facts pretty straight on this (but hey, i don't have a rally car) so someone correct me if i've got something wrong.

Andris Laivins
big turbo, slow car, no bang-bang

You guys are forgetting something here. This can be done easily and safely with an MSD 2 step. It puls the spark at a preset RPM an allows boost of the line. Never seen turbo damage or manifold damage due to it. Many people I know use it, including myself. Easy stuff, just hook it to the clutch sensor and everytime you clutch in you're ready race. Great for launches, or double clutching from a roll on. Enjoy.
John
B12 Sentra w/ JDM SR20 and boost among other things
New Orleans, LA

Originally posted by NismoDriver
You guys are forgetting something here. This can be done easily and safely with an MSD 2 step. It puls the spark at a preset RPM an allows boost of the line. Never seen turbo damage or manifold damage due to it. Many people I know use it, including myself. Easy stuff, just hook it to the clutch sensor and everytime you clutch in you're ready race. Great for launches, or double clutching from a roll on. Enjoy.

Right, this is basically the same thing the JWT launch program does. They rely on preventing combustion in a cylinder to load the engine. Anti lag actually relies on raw fuel igniting outside the combustion chamber as well as loading the engine as above.. similar effect, but the anti-lag is a little more hardcore and I believe maintains a good deal more boost. It also operates without the clutch being depressed. The MSD 2-step is a great way to build boost for drag racing and can also be done with a Digital 6 and some others; two options without going to the JWT daughterboard.

Andris