Do you realize that to have a blue flame like that you will have to create a flame over 2200* F?????
Just to put it into perspective; the gases exiting the head in my turbo car at WOT never get hotter than 16oo* F..... To have 2200* at the tail pipe this means that you either heatrapped the whole exhaust to have a +- 0.9% heat loss rate or you have the exhaust gases exiting the head at over 3800* F.....
Not happening you will melt and fuse your valves & rings first, beyond that the incoming fuel will just ignite it self and detonate the engine....
This type of flames are not possible with out add-ons such as a flame thrower kit, spark plug in the back, color die in the fuel, aftermarket exhaust with a tune to created the effect or other.
here it is a reliable source video.... and I do not see any blue flames even at an open drift or wot racing the vert. The only "backfire I see is when he goes to Race mode w/ LC.
http://www.youtube.com/watch?v=FAIGp_prsWU