UCA never touch the shock tower never bottom out. function and form suspension spring preload never change only the height changes if you are ridding on some cheap *** suspension u will mess up the UCA and put a hole in your shock tower.
http://www.6thgenaccord.com/forums/showthread.php?t=26152
still can go another 1.5-1.8 inch lower on the coilovers but the frame will be laying on the ground. HAHA