While searching, I bumped into an old thread in the FB section that mentioned "key-banging." Just before stopping, these guys were keying off their motors (they didn't say if they left it in gear) and coasting to a stop (coasting - so maybe they were in neutral.) A few seconds after stopping - BANG! Massive backfire out the exhaust, with flames to boot.


So I start looking for more info about this. There isn't much to be had, but I did find this comment:


Call me immature (you won't be the first one to) but this sounds like fun.

But these are all carb'ed cars they're talking about. Can we pull it off with our EFI 7s? I figured I'd ask, since I don't feel like going for a drive just now.

 

hehe Doesn't sound like a real good idea.... lol


I don't know if it would work, when you turn off your key you turn off your FP, so pumping the pedal won't really do anything ( I think, I could be wrong).

Besides, there's lots of vids of guys in FC's shootin' flames without doing anything like what you're talking about

 

Not sure, but I think it would still work with EFI. Turn the car off, turn the key back to on position so there is power, pump the gas pedal. Not sure, might work, I won't be trying it in my car anytime soon but go nuts.

later
-Justin

 

To my mind, this would be a way of doing it without warning people about what was on the way - usually, to get an NA to throw flames you have to rev the **** out of it...


Good point about the fuel pump - guess I'll have to put a Holley on the girl first.

 

The fuel pump will have power if you turn the key back to the on position after shutting off the engine. Just keep the clutch in and then floor the gas pedla a couple times.

 

hahha YES you can do key-bangers in an EFI rotary.. Since they run rather rich there is always a bit of fuel left to goto into the next exhaust cycle (without ignition)
In fact mine used to pull some RIPPER flames when doing keybangers... This is with a straight pipe for an exhaust and a slightly rch fuel map (microtech.. )...

You don't need to even touch the accelerator pedel to do it, just switch the car off and on whilst in gear... generally better at about ~3500rpms..

Great fun... Very good way to scare the **** outa people if you want to...

 

Also, with a carbed car there is a chance the fuel pump is mech. If that is the case the gas would still flow.

James

 

Sounds promising...

I'll give it a shot the next chance I get (hopefully at night.)

 

Another one for the "Stupid FC Tricks" list...

 

You better have meant that supportively; you don't want the rotary gods to come for you...

 

Dude.. That has to be the single DUMBEST thing I have ever heard of....

The FC fuel system shuts off anyways..

 

Alright, lets get a little more technical....

This works for carbs since fuel is jetted in with airflow... so by shutting off the engine, you still have airflow, you still have some fuel pressure (or a lot of fuel pressure if you have a mechanical fuel pump) and therefore also an air/fuel charge to cause the backfires.

Now, when you shut off an EFI car, you cut the injectors, fuel pump, and spark Putting the car back into the run position with the clutch out would start the car, because the injectors, ignition, and fuel pump would all come back online, and the engine would be turning over. With the clutch in, nothing would happen.

Now, the injectors ALSO fire in relation to eccentric shaft rotation, so that the injector pulse feeds a direct combustion chamber. There would be no fuel for any adjacent rotor chambers, and no richness, like White FC indicates. (rich exhaust charge would be no different than just revving the engine up).

The only way this would work with EFI is if the key was cut mid-cycle, so that there was a fuel charge going through the combustion chamber, but the spark was cut just before it could ignite the charge. Thus, you would have just enough fuel for one or two chambers of combustion being sent atomized to the mufflers.

Based on this, it *may* work, but not near as well as you would with a carbed engine.

 

I gotcha on that one. Fuel injectors fire before the ignition... so you could have an air/fuel charge going completely unignited through the exhaust.

You're never on MSN anymore...

 

I am on right now!

 

Of course I meant it supportively, you Photochopping Buttmunch.