For the love of God, please HELP!!!

[Rainman]

Alright I got some aftermarket 17 - 7 rims put onto my car. The tires were 45's. The problem is this...whenever I go above 55 mph, my car and steering wheel starts to shake! My whole car feels like it is gonna bounce off the road! It drives me nuts! I balanced them 2 times at Firestone and still nothing has changed. I got something called "hop stopers" and put those on...it helped some but not enough to satisfy me. WHAT CAN I DO!!! Help would be more than appreciated!
Rainman

[GOSPEEDGO]

That sucks!

have you locked up your brakes? if so could be flat spots in tires

should you have those plastic spacers that fit on the inside of the wheel and slip over the hub? they ensure a snug fit.

is everything tight? ie. lugs,suspension and steering components.

last but not least. could you have a bent rim?

hope this helps

[Maelfyn]

Only thing I can think of is get an alignment with your 17s. Seems strange though since it doesn't happen with different wheels. Or does it?

[DrivenFast]

maybe rebalance the tires, my 2 cents