Turbo boost is a feature built into the cpu and will work regardless of what motherboard you use (z, b, h). It should be enabled in the bios by default. Turbo boost ratings are given at the highest potential. With a single core maxed at 100% it will boost to 3.9ghz. If two cores of the cpu are heavily loaded to 100% the actual turbo boost will typically drop to 3.8ghz and if 3 or 4 cores are all loaded to 100% during heavy multitasking or a heavily multithreaded program the max turbo boost will drop to 3.7ghz.
If you are looking to overclock a cpu beyond its rated speed you should consider a k series and pair it with a z series motherboard.