Ok,
So, if you really want your car to shoot a flame out (like a few feet) here is one way I've been told. I've also been told not to use it on the street, which I'll explain in a sec. I wouldn't do it myself.
As you are flooring the car getting ready for a shift, you set up your management to continue fueling as you push the clutch in (and back off for that second) as you go through the gears. It also retards the ignition which keeps the turbo on boost, and shooting raw feul out the back (which will catch fire if the exhaust is hot enough). Runs great, and heaps of fire (think v8 supercars). Cat, no cat, its doesn't matter, as long as you have a resonable sized pipe.
The downside is if you are driving down a hill, backed off, the car will still be feuling - which means the turbo will get HOT. Apparently even coasting down a hill for 30 secs or so can make a turbo glow red and fail.
Another system is to shoot a flamable gas (nos?) out the exhaust from near the diff, using a spark plug to ignite (ah lah Fast and Furious).
not that i'd bother...