Ok, you are on the good way. You have to know that NB sucks: to reach a stable FSB of 400 x 4 = 1600 MHz and 8 Gb of ram you'll get into hell!
But let me know that 1800 MHz FSB with 8 gb dual channel is very very good for that mobo, congratulation! Now your only problem could be the CPU: in order to grow the multipler, you should increase VTT voltage, this will cause an overheat. I suppose you have now 8 x multipler (800/4 * 8 = 3600 MHz). Lets try x9, you should reach 4050 MHz on CPU, but this will need hughe overvolt on CPU vCore and VTT.
Just try and let me know, your result is good!