I would not go anything less than 2.5bar...
if its hot day, pressure will raise a bit when tires get heat up after few laps.
I would set rear a bit higher than front since fwd cars will understeer, so it usually balances a bit.
Plus as the fronts will heat up more the pressure will raise more in front.
Last time when i hit the track with my old 1P i used 2,7 front / 3 rear