Might be an unbalanced wheel/tire.

 

If you speed up does it stop or just get worse?

 

gets worse, tires get louder, like the road is really ruff , i have no pwer steering, im thinking i need wheel balance or wheel bearings.

 

I would jack the front of the car up and check as described in the FSM and Haynes manual. It will show you how to pull on the wheel and see if there is play in it or not.

 

If they are the same size, put the rear tires on the front and try it. If car was just aligned, I would surely think they would have checked all suspension components and wheel bearing play.
If alignment was out of spec and corrected and same tires on front, could be they are in a different plant on the road and that might be causing the problem.
Balance was my first thought though.

 

make sure your wheel bearings are tight...if they check out then it's your wheel/tire setup. swap front and rear, see what happens. you cuold have a bent rim or even a warped rim (one that is WAY out of round but looks ok to the eye). hubs could also be the problem but not likely.

 

Tire pressure.

 

tire pressure differences will not cause violent wheel shake...just some annoying vibration and a small one at best. Get a good balance done, if that doesn't help you have a bent/warped rim most likely.

 

That is a tell tale sign that your tires need to go in for rebalancing. Mine used to do that. Was solid up until 45mph or so, then the rotational vibration would kick in and get progressively worse with speed. Getting the tires rebalanced fixed it 100%. It also could be a sign that your front tires are out of round. Which no balancing can cure.

 

on my last car i had a shop put my azenis on so poorly that i couldn't drive the car. They were THAT unbalanced. Maybe a weight fell off one of the rims.

I'd also take all 4 rims off and see if you bent one. I bent a crappy Z racing rim one time by just hitting a pothole.

 

Tire pressure >> helicopter sound at/above a certain speed depending on the amount of pressure off.

 

What rims do you have? Do you have hub centric spacers if you have aftermarket rims?

 

Had the same problem when i first got my FC, was a combination of tires, and the one rim was bent a bit allthough completely unnoticable....

 

mine did the exact same thing when I first got my FC, The wheel bearings just needed tightened. There's a how-to on the FC3s site that explains it very plainly.

 

i went through a **** load of things trying to chase down a vibration i had,.. Check your ball joints.. if they aren't new, then replace them.
Mine cost me $78(each) CDN from Mazda... trust me, it helps!

 

Also worth mentioning: Some tires have been worn in such away that a problem like that cannot be corrected. (besides replacing the tires)