How low can I go?

[lkapimp216]

I am having BC Racing coilovers installed tommorrow and would like some help in figuring out how low I can go without shredding tires. I don t have my wheels so Im trying to figure it out so when they get here I can just throw them on and be done! I have a 2006 Lexus GS 300 RWD The set up Im running is Vossen wheels (F) 20x9 +22 245/30-20 (R) 20x10.5 +29 285/25-20 from my calculation I came up with 25.5 in the front and 25.25 in the rear. I am shaved in the front and rear already thanks for your help!

[S30ZG]

Do you have any work done to the fenders/quarter panels? You may need a roll if you don't plan on rubbing depending on how low you go.