Nasty Popping Sound!!!

If it's not coming from your rear then it your control arm bushings are shot and the tension on the bolt and no full rubber bushing is scraping metal to metal. Most likely your uppers. Get under the car and inspect the uppers and lower bushings and check to see if they're dry rotted. :nice:
 
Another thing might be an axle bearing??? Jack to get the wheel up in the air a tad...Give it the up/down/left right movement....If its spanked you feel it...