2017 Hillclimb Challenge: Subaru WRX STI

Subaru WRX STI prepared for action in the paddock at Doune.

I have heard people say that if a car is correctly set up for one piece of road, it will work well on any other. What follows is partly a demonstration that this is not true.

The 2017 motorsport season has been more frustrating and less rewarding than I had expected. Five manufacturers (no, you’re going to have to guess) either agreed, or offered without being asked, to supply cars and then backed out of the deal. Even more annoyingly, I was denied entry to an event because the organising club decided to ignore its own regulations. To say that this has caused me some disappointment would be to understate the case.

I can say, though, that things have ended on a high note. Subaru made a promise to become involved with the Primo plc Multi Vehicle Insurance / Nationwide Association of Blood Bikes Hillclimb Challenge and stuck to it, with the result that I turned up at the fabulous Doune venue in a WRX STI, all ready to do battle.

Well, fairly ready. I already knew that the other two entrants in the Road-Going Series Production Cars over 2000cc class would be Steven Darley and Justin Andrews, and that they would be sharing Steven’s older Subaru, a first-generation Impreza Wagon which looks fairly innocent (it even has a dog guard) but, as we’ll see, very much isn’t.

Doune is a forbidding venue where experience counts for a lot. At this event there was a well-supported barbecue in honour of a wonderful man and former Scottish Hillclimb Champion called Alex Graham. Alex has been competing at Doune for forty years, and even he says he hasn’t yet mastered it.

Subaru WRX STI powering out of Garden Gate corner at the Doune hillclimb.
Photo copyright Paul Hunter.

I’m a newcomer compared with Alex, but I’ve done at least twenty events there. Steven had done only two, neither of them in the Wagon, while Justin had never been to the place and hadn’t driven the Wagon before. Advantage me? Yes, to some extent, but there were two problems.

The first was that they are both very experienced, very successful drivers who would surely – and in fact did – get to grips with Doune very quickly. The second was that the Wagon is an absolute monster. Steven said its power output has never been measured, but reckons that it produces about 600bhp on ‘low’ boost and somewhere between 650 and 700 when the turbo is cranked right up. The gearbox and suspension have been uprated to match this, and the car runs on the best tyres available.

Long story short, Steven took more than two seconds off the class record, leaving it at 47.34, and would certainly have got into the 46s when he went to full boost if he hadn’t damaged the front left wheel and damper after hitting a kerb. (He still managed a 47.59 on that run, which just goes to show.)

Even approaching this level of performance in a showroom-spec 296bhp WRX STI wasn’t worth thinking about, but I did have a target of my own. Last June I lowered the unofficial Doune record for standard cars to 50.50 seconds in a Ford Focus RS and came close to beating it in September with a 50.81 in a Mercedes-AMG A 45. The Subaru is less powerful than either, but I thought a 51 might be on. If I could manage that, I’d be happy.

To begin with, there seemed little chance of it. I picked up the car on the Friday and immediately picked a setting for the centre differential. There are nine to choose from, and I went straight for the second lowest manual one, since it had worked well in another WRX STI (admittedly fitted with very sticky Toyo R888 tyres) which I competed in at Prescott two years ago.

Blurred action shot of Subaru WRX STi leaving the start line at Doune.
Photo copyright Paul Hunter.

I spent an hour driving the car on local roads, including the wonderful Duke’s Pass just north of Aberfoyle, and on that diff setting it felt wonderful.

The following day the WRX STI felt as if it had turned into something from a Stephen King novel. On my first two competition runs the thing was undriveable. The slightest movement of the steering wheel sent it spearing off line, which is not what you want on a track which is some places narrower than the car was long. I was having to lift off the throttle for corners I had never previously thought of as corners at all. How could this possibly be the same car I had enjoyed so much on the Duke’s Pass?

Advice was sought and given (some of it, very sportingly, by Steven Darley). Plans of action were devised. The tyre pressures were altered radically. I thought about adjusting the suspension, but you can’t do that in a WRX STI. A theory arose that the front wheel alignment had gone askew – nobody in the paddock had a set of tracking gauges they could lend me, but with the aid of two spirit levels and a tape measure we established that it was what Subaru said it should be.

Eventually, the suspicion arose that the centre differential setting which had worked so well on the road and at Prescott wasn’t working here. At this point, a guinea pig joined the ranks. Challenge regular Alisdair Suttie, who had foregone the chance of competing in the Subaru, found himself without a drive when the car he was due to drive instead had to be withdrawn due to a seized engine. He was duly bundled into the WRX STI, now with the diff set to Auto plus, and sent up the hill with orders to report back on how it handled.

Subaru WRX STI powering up through the Tunnel at Doune.
Photo copyright Paul Hunter.

He recorded a 53.73, far better than the 55.09 which was all I had been able to manage so far. He also complained that the car was understeering on every corner, which at least meant that the diff change had had some effect since the last time I drove the car it was trying to spin when going in a straight line.

It seemed best to try another setting which was in the same general area as Auto plus but at least one step away from it. I switched to Auto minus, and on my next run the car handled beautifully. It went straight when I asked it to, and there was just enough oversteer to help me round the corners without needing any (or much) opposite lock. At last we had a car which behaved the way Subarus are meant to.

Some online research on Saturday evening helped to explain this. In each of the manual modes, the centre diff has the same pre-set amount of lock all the time and the front/rear torque split is 50/50. In Auto plus, the amount of lock varies according to what the system thinks is required, and while the torque split can change it is kept to as near 50/50 as possible. In Auto minus (which, if I ever have a daughter, is what I will call her in honour of how well it works) the torque split is 41/59 – just the right amount for Doune, as it turned out.

My first competition run on Sunday took 51.98 seconds, just within the original target, but it was quite scrappy. My fault. I had been talking to too many people before hand and hadn’t left myself enough time to get into the zone. On the plus side, I was second in class behind Steven. Justin had very kindly spun the Wagon so far off the track that it came to a halt doorhandle-deep in bracken, while Alisdair lost time with a wild moment at the exit of Junction, as you can see below.

A wild moment in the Subaru WRX STI on the exit of Junction corner at Doune.
Photo copyright Paul Hunter.

At least he couldn’t complain about understeer after that.

Before his final run, Alisdair said he’d be content if he could get into the 52s. After it, he found himself in the very different position of cursing himself for not managing a 51. He would have done it comfortably, but a missed gearchange cost him vital fractions and he ended up with a 52.04. Pretty good, I thought, considering he’d had two runs less experience of the car than I had.

Justin also missed a gear in the Wagon on this run and recorded a 50.49. I didn’t think I’d be able to beat that since my best effort so far had been a second and a half slower, but knowing I had definitely finished third I thought I’d hurl the WRX STI up the hill as fast as I could just to see what happened.

It was a hell of a run. Fully in the zone this time, I flung the car into blind corners so quickly that I thought I would hit the barriers on both sides at the same time, and the car lapped it up. It didn’t feel much like a racing car, as the Honda Civic Type R I drove here in 2015 had done, but it did feel like a well-sorted tarmac rally car, which was nearly as good.

Everything was going the way it should until I was within sight of the finish line when – gah! – I tried to select third gear too quickly and had to make a second attempt. The initial frustration evaporated when I saw 50.86 seconds on the timing display. I had lost maybe a tenth with the fumbled gearchange, which would still have left me behind Justin, so it didn’t matter really.

Subaru WRX STI cresting East Brae corner at Doune.
Photo copyright Paul Hunter.

There was some regret. If I had known from the start that Auto minus was the correct diff setting for Doune, I would have had six runs to work on my driving, rather than wasting the first two on fighting against the car and a third on checking that it was now as it should be. I would certainly have been in the low 50s and perhaps even the high 49s. This would have put me ahead of Justin, but if we’re going to give me the benefit of the doubt we should do the same for him and assume that he would have had two clean competition runs and ended up with a well-deserved 48.

Still, even the way things were, the Subaru had, despite its power disadvantage, come very close to matching the Focus RS, and was just a finger click away from beating the Mercedes. I would be very happy to compete again in any of these cars, but if I had to pick just one of them for a return visit I think it would be the WRX STI.