Being somewhat anal around tyres (the only thing between you and the scene of the accident - and only a tiny contact patch in relation to the vehicle's size), most of the 'old stagers' will know I've long been a fan of these Avon tyres. I've experimented over the years with various tyre pressures/shock absorber settings and would be loathe to offer guidance as my results clearly show its not an exact science.
My (limited) racing experience (much of it also on these same Avons) would lead me to humbly remind you that the more air in a tyre, the wider the grooves in the tread. In other words, the tread opens up, which is why the considered wisdom amongst racers is to increase tyre pressures in the wet (but only by 2-3 lbs/ft).
All in all, my own time with all 9 Cobra reps I have owned suggests starting at say 22 all round, then gradually try increasing the pressures 1 lb at a time (per axle) to see what feels
right for you - in other words until you arrive at the optimal ride/handling combo. Currently that's 24F/26R unless I have the wife's luggage on board which means 25F/27.5R