Originally Posted by Oranoco
The flamer kit I have (as fitted by SCC) has a sparkplug in the tail pipe and a coil. It relies on the natural unburnt fuel present upon lifting of the accelerator not cutting power to the normal running coil. Turning the ignition off as you come onto boost is a sure fire way to fuck something (probably expensive) pretty quickly.
I had one when it cuts the coil and it worked fine. Never would do it on boost though!