Overclocking on the Intel Z170 platform is pretty easy. The easiest way to overclock would be up simply change the frequency divider in the BIOS. To achieve the best overclock we try to stay with the timings that the XMP profile recommends, but we will loosen or tighten timings to get the best overclock possible.
This kit has a normal speed of 3200 MHz so I moved the frequency divider up to 3333 MHz keeping the same timings and voltage as the XMP profile. The kit made the jump no problem, but did not pass our stability test.
I decided to loosen the timings from 16-16-16-36 to 16-17-17-36 and bumped up the voltage to 1.40V. This proved to be a very stable overclock.
I stopped there as this is already clocked quite high. Keep in mind the JEDEC frequency for DDR4 is only 2133 MHz.