[MENTION=829]rastok[/MENTION], yours is probably doing it because you didn't set the spring against the stop, so it's shifting around on the strut.
[MENTION=1664]Butterybunz[/MENTION], How low do you have them set? Even though manufacturers will tell us that they can drop x amount, there is usually an ideal setting and then there's the "too low but within advertised range" setting. If too low, the spring will be compressed too much and bind when you turn it. This is simply because a compressed spring is stiffer (rare but windings might touch) and fighting you as you turn the wheel. Hence the boing bong bong you get when turning. I have a set of BC racing on wife's grocery getter and it drove me f'in nuts for months. Ultimately, raising the coils just a tiny bit to unload them a touch shut it the hell up.
But remember, coils can be noisy. Aftermarket suspension is PITA folks...but soo worth it