street tyres aren't a soft enough compound to become hot and therefore sticky...unless you're using semi'slicks or full slicks
those people that give a little chirp are wasting their time as that doesn't do anything at all; in order to get your street tyres hot enough you have to do a long, hard burnout, and usually after a couple of those you can kiss your tyres goodbye
tyre pressure, maybe...maybe not...it all boils down to what people have experienced...
I'd say a lower tyre pressure, like 20psi, would be pointless (no offence gtst v-spec! ) but you're caving the tyre, and only gaining traction on the outer edge of the tyre, and not all the way across...that's why I tend to think that an intermediate pressure is best...and theoretically should be since you'd have maximum traction
so in conclusion: unless you're running slicks, steer clear of burnouts and don't drop tyre pressure *too* much
I stress - IMHO