Just got my 18" chromies today, with a 215/35R18 tyres.

Now I have a problem with tyres rubbing the guard.

I had my old wheels and tyres at the back so its kinda loaded. Anyway, when making turns at a say 30kph (round abouts and not so sharp turns) the front tyre is rubbing the lip of the guard. But when I'm making sharp turns, like the steering wheel fully locked to one direction and slowly move the car the tyres wont rub. I figured that the weight of the car is transferred to one side when turning at a speed and it pushes that side down making the tyres rub the guard.

Just tested my car again with me in the car only. There were no rubbing or anything like that. There were no problems also when I have one passenger.
However, when turning at a speed and if there's a bump on the road it still rub the lip. Like when it hit the bump I can hear the tyre rub the guard

Do you guys reakon it's time for me to upgrade my suspension system? You know like changing springs and shocks? After I put my 18" wheels on, the car went up a bit, but because I'm having problem with tyres rubbing, I'm not sure if I'm going to get it lowered.

Anyways, what brand or type of springs and shocks would be the best and how much you think I will be spending on it (parts and fitting)? If you guys have these set up and had your car lowered and have no problems, how low did you get it lowered?