Peter’s troops aren’t naïve about what can happen at very high speed, but they can’t be expected to know everything. The stuff they have thought of is the stuff I needed them to think of. There’s no way, for example, you’d try this on stock Falcon brakes, so four-piston APs are reassuring.

So it’s one last fiddle to temporarily disable the standard 230km/h limiter and blaze, quickly, before the computer figures out it’s been diddled.

As engines go, this is strong. Bloody strong. So strong that the sweeper onto the runway is best taken, delicately in third. Into fourth and the thing’s huffing and howling.

Falcons normally stall in fifth. Not this one. It just keeps surging. But then the air starts to play around the nose at, maybe, 260. Hard to know, with the speedo non-functional.

A bit faster and it starts to move all over the track. It’s getting to be seriously hard work with the tacho needle j-u-s-t off the limiter, maybe 30 revs shy. The engine’s not the problem, it’s the aero. Avalon’s airstrip is wide enough to land jumbos, but I doubt any of them ever uses this much width. It’s just walking the nose across the road and back again, sometimes sharply.

And then it’s over and through the trap. The aero is, if anything, worse under brakes. While moving off the throttle and onto the brake pedal, the thing steps a good three car widths sideways, then another three as the nose pitches. From there, it’s junking left, then right, and then back again until, around 230 or so, it all becomes fairly benign.

It took a lot of road to stop, probably because I hadn’t appreciated exactly how fast it was travelling. And it was travelling bloody fast, 307km/h didn’t seem right when it came over the radio, but in, hindsight, with the way it moved around, it kinda made sense. And I’m, not real sure I want to do it again.

The APS PHASE III XR6 Turbo at speed. Click here for pictures and video action - at 307 kph!

Psssst. Wanna hear about Phase IV, and even Phase IV?

Among the Phase IV’s numerous tweaks, the top half of the inlet manifold has been replaced with a custom-designed plenum to house an additional six injectors that supply fuel for more than 500kW of crankshaft power.

APS’s Peter Luxon also reveals that, in testing, the Phase IV system has produced over 400kW of rear-wheel power, and there’s plenty left.

Phase V is on the drawing board, says Luxon, but the engine’s innards will need serious beefing-up. Pistons and conrods will be replaced with heavy duty items, with the turbocharger upgraded to a much larger 700kW-capable compressor.

With the right set-up and tuning, says Luxon, “One thousand horsepower, in the old money, shouldn’t be out of the question.” Gulp.

The Phase III XR6T test mule has completed more than 140 dyno runs and numerous quarter-miles, and had a thrashing with the press behind the wheel.

With its 400kW (plus) of crankshaft power, the stock T5 XR6 Turbo transmission has stood up admirably. It has not been modified, apart from getting a fresh sump of high-quality gearbox oil.

It’s amazingly quiet, the synchros still work like new and the shift is positive and precise. The same praise can be heaped on the differential and axles, which have stood up to the torture without failure.

The only part of the driveline that has required attention is the clutch. It was factory-designed to be a weak link that slips as power increases. APS’s solution is an up-rated Phase III-capable clutch and pressure plate assembly.