you really shouldn't be rubbing at all with those tire specs and sizes. I was on the exact same thing and I did rub/flare my fender a bit only on one side while at the track but for street driving, no way.
get an alignment and you will be laughing.

 

I'm running the same wheels (in Mercury Silver) with Michelin PS2s in 225/255, and I haven't rubbed once. Lowered approx. 1" on Bilstein PSS9s. Running a more or less stock alignment, with 1.8 degrees neg camber in the rear.

Does the tire you're using have a very square edge profile? That's about the only difference I can think of, short of suspension parts being bent or otherwise out of whack.

 

My tires do have a good contact patch but they are not and I had the allingment checked before I lowered just to be safe that there is no damage to any suspension components and my car was perfectly within spec aside from one side sitting a tiny bit lower which is normal apparently.

 

What Specs did you end up using?

 

i have volk ce28's at +50 / +63 like yours, with 225 / 255 tires. using j's racing camber joints. lowered until the top of the tire is slightly inside the wheel well in front, and slightly outside on the rear. camber = -3deg in front, and -3.25 in rear. the tires DO RUB under extreme cornering at the track. i cannot definitively say if it's the front or the rear though, but most likely the rear. it only rubs in high-g sweeping turns, and very slightly.

one time i had a passenger, and i went up a driveway................ and the fronts more than rubbed--they totally bent out the fender on the passenger side. so, i would say +50 with j's camber joints in front could result in damaged fenders, even at -3deg camber. oh well--now i have an excuse to get a widebody kit.