Bad...Bad...Bad...Bad Vibrations!(Beach Boy Voice)

Hello, my name is jason.. but let me get right into the problem.. I own a 2005 g35 coupe that just broke 51k mile barrier and now i need some front suspension work. Now ive had 20inch wheels on my car for a while.. i started to get a slight popping sound in the front left ever so often in the front while turning or hitting dips in the road.. so i decided to take off the 20's and put my winter 17's on... I got all winter wheels balanced and then got a alignment done on the car.. now the car rides smooth but i notice while turning at speeds above 50-55mph+ i get (crazy) vibrations when turning the wheel just slightly to the left or right.. i think it may be the front right wheel that is making the shaking but its really unberable and i need to fix this problem.. I plan on lifting my car on jacks and get a look underneath a well this weekend but i would like some insite on the possible problem..