I had been interested in running this particular route around Halls Gap for quite a while, so upon discovering the FKT website and this route as an existing FKT, decided to have a crack a couple of days later.
Began at 3:15pm from the well marked GPT (Grampians Peaks Trail) trailhead which is right beside the caravan park and began to climb, following the yellow GPT arrows. As luck would have it, summer had finally decided to show up just in time for my first FKT attempt and the temperatue was significantly higher than I'd imagined, which made the thought of a swim at Venus Baths very tempting as I ran up the trail adjacent to the creek, rapids and waterfalls, but I embraced the added training impulse :) and continued up towards the Pinnacle. I was familiar with this section of the route and was already aware of a slight detour that I would have to take due to works being conducted in the 'Grand Canyon' just before the Pinnacle summit. I believe this detour is slightly longer than the intended GPT route through the Grand Canyon route and perhaps added a minute or two to my overall time. This was the only part of the entire route cordoned off. I'd made good time up to the Pinnacle, hiking some stretches of steps. After making decent progress on a lengthy runnable section following Sundial Carpark I was scrambling up to the summit of Mt Rosea, hiking for the most part and this was slow going. This entire route is 'designed' for hiking, though trail runners might disagree, however this section is particularly rocky, steep and technical. Views from the summit of Rosea were great as usual and following a little more rock hopping downhill, the trail turns into an awesome dirt single track all the way down to Borough Huts. Passing through Borough Huts campground and continuing around Lake Bellfield, there's finally some reprieve from the mountains as the trail levels out. I thought this flat section was going to continue all the way back into Halls Gap, it did not. This section of the trail is a dirt road used by Parks Rangers and suddenly I was confronted with what can only be described as a wall. So I hiked up, jogged down (if it was less than -30%) the undulating road which lasted until the final GPT marker directs you back onto Tandara Rd, into the streets of Halls Gap and along flat bitumen for a couple of km's until you complete the loop.
This FKT attempt was unsupported. I took 500ml water, 500ml carb/electrolyte mix - these were both refilled once in the creek at Borough Huts. I also took with me 1 Clif bar, 1 mini Mars bar and 1 mini Snickers bar and consumed all along the way. Didn't resupply with food. Only other supplies I carried with me were a compass, compression bandage and emergency blanket. No gels were used in the making of this FKT :( ...
P.S As already mentioned in the comments, this FKT should be re-labelled as "Grampians Peaks Trail - Central Section Loop from Halls Gap" or something along those lines. Once completed the actual "Grampians Peaks Trail" will stretch from Mt Zero, pass through Halls Gap (and include the section of this loop from Halls Gap to just after Borough Huts) all the way down to Dunkeld and will be approx 160km in length.