Tyre pressure at launch

[247bhp]

Any indication on the pressure of the back tyre when doing drags?
Standard tyre pressure is given as 290br
I understand dropping the pressure give better grip at launch, but how much is good?

 

[WWJD]

No draggers in this section of forum? ? maybe try this question down there under PERFORMANCE section?

Also, this place is a little slow since many think this site is down until Friday [previous maintence window that was announced]