If you’ve wondered how what an early WRC Imprezza could be capable of without all the rules chocking back power, check out this video of Alistair McRae smashing the Leadfoot Hillclimb record at Rod Millen’s ranch in Hahei, New Zealand. By doing so the Scottish rally driver made it three-in-a-row with outright wins in 2017 and 2018.
McRae’s GC8 Subaru Impreza has lived a colorful life. After being crashed by Juha Kangas at the Rally of New Zealand, it found a new home with the late, legendary Possum Bourne, who rebuilt it for the Race to the Sky in 2001. Then Kenneth Ericsson, another WRC driver, campaigned it until 2007, and finally, Alistair McRae picked it up in 2015. For most, a Prodrive-built WRC car would be more than enough. However, when you’re an ace and the brother of arguably the best rally driver ever, nearly tripling the power output isn’t all that outlandish.
The motor is incredible. Only displacing two liters, it takes 42 pounds of boost to make its 850 horsepower. The E85-fed motor is extensively modified to handle the high boost levels, and in the name of greater reliability, it ditches the headgasket. In its place are gas rings, which sit at the top of the bore and seals between the bore and the cylinder head. These rings expand with compression and provide the seal.
Bigger heads, valves, cams, and a massive BorgWarner twin-scroll turbocharger are all part of the combustion cocktail. Full boost comes on around 4,500 rpm and screams all the way to 9,000 rpm. The response is something else, especially considering how small the motor is, but once it comes on, it’s quite happy to spin the wheels.
Having a WRC car as the base means the driveline didn’t require extensive modification, but some upgrades were made. Locked center and rear differentials replaced the original active differentials just in order to handle the added power. Though this hurts the car a little in hairpins, it’s a better decision net-net when major power delivery is a factor; the active units simply couldn’t handle the thrust.
The Reiger Racing suspension is tuned a little softer than usual since the road is so smooth, which gives it a little more traction; a little counterintuitive, no? Still, with the power available, the car dances over the crests of Rod Millen’s famous driveway. Fortunately, he has the hands and the confidence to catch the tail when it slides (1:07 in the title video), and he doesn’t seem to be too intimidated with the endeavor of juggling rapid gearshifts with the dogbox, wrangling snap oversteer, and avoiding the hydrangeas on the way up.