I take Protein supplements though, and as I weigh 85kg I was consuming approx 170g of protein per day (supplement + food combined) going by the generally held formula.

Is it something like 70g max is the suggested consumption for the average male adult, so am I doing enough in the gym to warrant that extra 100g or is my gym work being completely undone by taking too much protein which turns to fat?

I can regulate the Carbs ok, its more the protein I am bothered about.

I tend to do a 1 hour session on the weights 3 times a week, 99% of the time 3 sets of 8 of whichever exercise, always with weights I am really having to work on the 7th and 8th rep, so I presume I am putting a fair bit of stress on the muscles over that hour?