Yes and no. There are ways to force the processor to run at higher clock speeds but if you overrun those VRMs you could end up frying your CPU and motherboard. It is important to be able to accurately measure the temps of the VRMs if you are going to be pushing them and motherboard sensors are...
Trying to run an FX-8xxx on a 3+1 phase motherboard is a bad idea. Those boards can barely supply enough power to the FX-4xxx chips. I wouldn't even try to force the CPU to run at its full speed with that motherboard. You might get better performance out of under-volting and cooling the VRMs...