For those of you who think the Isle of Man TT is all about bikes, here’s rally ace Mark Higgins turning his 600hp Impreza STI into a street sweeper on the way to a 206km/h lap of the Snaefell Mountain Course. Higgins, a Manx local, has been lapping modified Subarus around the TT course since 2010 but this year there were no holds barred in an attempt to break the record.
Higgins’ 2016 Impreza is by far the most extensively modified of all Impreza’s used. Previously the cars made do with minimal suspension mods, minor brake fettling, slicks and safety precautions like a roll cage. Not that a roll cage would have done much if Higgins hadn’t caught this epic tank slapper in 2011, which he promptly described as ‘the biggest moment in my life’.
A lot of work has gone into making an Impreza lap the Snaefell’s almost 60km in 17min 35.139sec. Starting with the 2Litre turbocharged boxer motor, which is essentially an old WRC motor with the rev-limit raised from 6500, to 8500rpm and the inlet restricted turbo ditched for a larger item. All in, the 2Litre boxer makes around 600hp and 550Nm of torque, which allows Higgins to make use of the car’s longer 4th, 5th and 6th gears.
During a lap of the Snaefell Course, Higgins uses full-throttle for around 80 per cent of the lap and the car’s set-up needs to walk a fine line between downforce and drag. Prodrive, who developed the car, have incorporated a ‘DRS’ system that lowers the angle of attack on the rear wing when the car and Higgins are eeking out those last km/h down Sulby Straight. The modified gearing, 600hp boxer and carefully considered aero give the Impreza a top speed of around 290km/h – plenty when a flint wall is your ‘run off area’.
The Impreza’s suspension and brakes play almost as big of a roll as the WRC derived engine at nailing a decent lap. The Prodrive built Impreza runs AP Racing brakes with braided lines and discs as big as the driver’s…talent. Everyone wants to be sure Higgins isn’t wanting for stopping power in the slower sections of the course. The suspension, from UK firm Exe-TC, runs a similar tune to a tarmac rally car to ensure there is plenty of travel to cope with the multitude of massive compressions, jumps and ridges that litter the course.
I’m sure you’re getting the picture that this Impreza is no ‘bolt on special’ and I’m seriously looking forward to some in-car footage being released of the lap. Higgins’ reckons there is more to come but it’s none-the-less impressive to think that his average speed is up almost 20km/h and lap time down nearly 1min 30sec compared to the previous record. If you were in any doubt of the man’s speed or commitment check out this video from 2014 where he walks you through a full lap. Who says the TT is just about bikes…