its basically an anti-lag box, as the name imlpies, takes away lag on launch
it retards the timing off the planet at launch and provides spark cut launch control
so the turbo is wound up heaps, thus you get "boost" at launch
1) is this harmful to the car in anyway??
if you have a cat it will fry it, if you have cermaic exhaust wheel, it will fry it
2) can u turn the Bee*R rev limter on and off or is it constantly running like that untill u remove it?
yes it has an on/off feature
3) how much do one of these cost?
maybe $300 tops ?
4) does this give "any" performance gain watsoever or is it just for the show off factor?
it provides boost at launch rpm, if you get the power down without wheelspin it would provide good launches.
i dont like your chances in rear wheel drive, but good luck