Copypaste from the nvidia link you posted earlier:
Note: The below specifications represent this GPU as incorporated into NVIDIA's reference graphics card design. Clock specifications apply while gaming with medium to full GPU utilization. Graphics card specifications may vary by Add-in-card manufacturer. Please refer to the Add-in-card manufacturers' website for actual shipping specifications.
You don't have reference design card.
You have a card made by what Nvidia calls add-in-card manufacturer.
Your card does not have TDP of reference design card. In your case card has TDP of 170W because EVGA chose to put that kind of bios to your card. EVGA also chose you can boost your TDP 10% to 187W. EVGA also chose that your card takes 75W from pcie1, 75W from pcie2 and the rest from the pcie slot.
So somehow you're saying the power being measured by the software is somehow disconnected from the stated TDP (145W), even though it's being represented as %TDP and requires that number to calculate against. And that the percentage would not change if the TDP were somehow able to be set higher, like 187 as you want. Or, somehow the TDP on these 970 cards can miraculously go 128% of reference TDP, something no 970 I've ever seen can do. 980's can barely come close to that, because they also have a significantly different power handling architecture, which I'm sure you also know.
You still have to deal with the observed power at the wall, and make the numbers fit as you wish without going over. I've only done the best I can do to do just that. If you want to add more to the GPU load, you'll just have to take the same amount away from system power, and there isn't much there to play with if you want to make any sense.
EDIT: Here ya go, the miraculous gamebox that gets 42MH/s on a mere 330W, see if you can make the numbers work to your liking:
ASRock Extreme6
Intel i5 4690K Devil's Canyon (oc'd in bios to 4GHz) w/CoolerMaster D92
8GB GSkill DDR3 2400
WD Black 1TB SATA
Corsair CX850M 80 Bronze
2xEVGA 3975-KR SSC ACX2.0+ (SLI bridge connected/enabled) P0 state for mining, 3800memclock, +50coreclock
Fractal case w/3 fans
Never trust what software says when monitoring maxwell power consumption.
330W is what that rig should take from the wall when mining IMO, you are just underestimating your GPU's consumption. 2 x evga tdp limited takes maybe 280W and the rest of the rig that last 50W. My nvidia rig happens to be quite similar to yours, differences being only 5 x GPU, SSD, gold rated power and 16GB memory. I'm sure that if I shutdown staking wallets, proxy servers and 3 x GPU we are looking at more or less same wattage when mining. If I want I can easily go beyond 1000W with that rig.
Those power pins really matter. Manufacturers at least try to run within specs, 6-pin is rated at 75W and 8-pin at 150W. Yes I know those connectors can deliver much more if GPU asks and PSU delivers but that's another story... Average 6+8 pin model is allowed 225W + slot before bios limit kicks in and some extreme cards have 8+8 pin connectors.
Some serious GTX 970 power consumption:
https://www.techpowerup.com/reviews/Colorful/iGame_GTX_970/25.html