How to do the backfire???

[dread1]

like stated before.

its pretty much a hickup, caused by a rich mixture and unburt gas leaving the chamber when the exhaust vales/intake vales are open/closed creating a vacumm affect. Depending on your overlap will determine the amount of suck or push which will lead the rich mixture igniting closer to the manifold or later. You have two BMW turbos i would suggest not wanting this to happen as replacing twins is a costly procedure for no real performance gain. in addition cats usualy stop the fireballs but depending on the substrate material they will break apart.

[PrimoM3]

I like this better...glowing brakes and all.

[ar design]

My Corvette pops huge flames with the methanol..... straight 3" pipes though

[Alext]

I can't remember exactly what happened to the exige, but the car (and driver) looked suprisingly OK afterward. I think it was a fuel leak.

[mtla4]

Happened on my 1er. I was running way too rich..the bumper was all black. I don't like backfires but I'd rather run stoich or rich rather then lean.

[Lester]

It can't be done. The BMW computer is way too smart to let something like this happen to itself. If it did happen by accident, the engine would go immediatley into limp mode, and you would have to take it in for service. Pumping raw gas into the tailpipe violates all of the computer's law abiding pollution control mechanisms.

[Muffnbluff]

Originally Posted by Brahmzy

I don't think anyone really WANTS to do it. It's a side affect of running catless exhaust on a lot of turbo cars...

Exactly. I remember you from IWSTI, so you are familiar with the old video of Ben shooting flames out his catless cobb exhaust.

People act like it's some big ricer thing, but it's just running rich.

If you see that coming out of an STi odds are the car is just running an OTS map, any protuned STi is going to have the a/f dialed in to where it won't run rich enough to shoot flames.

[1013mm]

you need to have....

[White1]

Originally Posted by beckham77

who knows how to doing it???

I have no idea why you would want to do it, unless you have som heavy mods, it would be very hard to do it with stock ECU and fuel injection system, its not good for your engine, and definitely not your back bumper.
Plus if it causes anything to fail, try to explain that to your SA, im guessing it would be a good way to get your warranty vaporized.

[Lester]

Sorry, OP - but this post belongs in the group with a few others like the guy who wants to fuel up his car while it is still running, and the guy who wants to close his door by using the window.

[clutchcargo]

Anti-lag.. Nice way to lunch a turbo

[Rearro]

Originally Posted by Alext

Not photoshop

ROTFLMAO!!!!

[Victory Road]

Shooting flames out of the tailpipe in general is not bad for the engine.

It is caused by running rich as said and some extra fuel is pushed into the exhaust pipes. Generally the fuel vapors condense farther down the exhaust stream closer to the exit due to the cooler temperature of the exhaust piping. Than it explodes and you get cool flames out the back, and you can pretend your a race car driver. It's not blowing up in or near your turbo or engine. No harm done.

Most cars will do it, newer or old. All it takes is a MAF tuned turbo engine (99% of new cars, and a whole lot of older cars), no cat, and an externally dumped BOV. Let off the gas, car runs rich....cool flames.

[Tom K.]

Originally Posted by RobMason

I used to think it was cool to make my dads '54 Willys Jeep backfire, while coasting, turn off the ignition, then turn it back on while foot on the throttle. Til the muffler blew apart. Not cool.

A few motorcyclists would do this back in the 70's when being tailgated as it always made the inattentive car drivers back off. I stopped when I moved from an inexpensive Yamaha to a BMW bike.

Tom

[135forthewin]

The only mod on my 135 is SSTT, and it pops baby flames out the back on the 1-2 shift (steptronic) at full throttle. It burnt the "black chrome" trim right off the edges of my exhaust tips...