My car has been making a sound from the passanger rear. It sounds like a flat tire, it used to only happen when i was turning left but now it happens almost all the time, it only happens at certain speeds but the speed of the thud changes with the tire speed. It makes a thud, thud, thud, thud, thud sound. Since the sound I have changed my tire, wheels, coilovers, and taken the exhaust off and it still makes the sound. What could it be??

 

Check all your bushings.

 

or rotors... was the car sitting for awhile?

 

Any cheap aftermarket parts on the suspension?

 

It's not a perfect fit, but you may want to check the wheel bearing.

 

Most likely your rotor as Hidenplanvew said or wheel bearing since the thud acts with rotation and it's not your tires.

 

I've never had a rotor do that. Bearing behaved like that but that was a different car.
But he never said what car it was so it would be odd if he has drums.

 

Bushings should be your first point of inspection. It is common for them to be completly worn after awhile and it could cause your described ploblems.

 

Jack the wheel up and try to wobble it side to side, does it have any play?

One of my wheel bearings looked like acid ate away at the inner race, just at one spot. It hummed really loud and matched to your description.

 

Yea, my skunk2 pro c's but its been doing that before i got them.

I drive it everyday, it just recently got worse though.

Its a 95 coupe disks all around.

I know the Trailing arm bushings have had tears in them, ill check them and the wheel bearing play tomorrow