Hillclimbing is massive business over in Germany, and as a result it spawns nutty cars, including this mad looking AX which revs to 9800rpm!
‘KING OF THE HILL’
What do you do if you’re done getting your adrenaline fix from racing bikes? Build a storming Berg Cup AX, that’s what! Words: Jamie. Arkle Photos: Axel Weichert.
Hill climbing is a serious business in Germany, bigger in near enough every quantifiable way than it is over here. Of course the very top tier of the country’s myriad of hill climb championships is the infamous KW Berg Cup, where be-winged monsters, DTM-refugees and the odd ex-F1 car take turns to shoot up faintly ridiculous mountain passes. It all makes Prescott Hill and Gurston Down seem a mite tame, something that only becomes clearer when you delve into the various sub-classes and take a closer look at some of the cars. Opel Kadetts, VW Golfs and BMW 3-Series are all incredibly popular, but there are also some left field choices, such as Corsa As (Novas in Vauxhall-speak), Toyota Starlets, and the Citroen AX you see here.
In a field largely dominated by rear wheel drive classics and ballistic single seaters, this little Citroen stands out a mile, and for all the right reasons. It’s been built by Manfred Schulte, a successful motorcycle racer with a penchant for speed and extreme builds. The AX holds a special place in Manfred’s affections as it was the car he began his association with hill climbing in, though the actual car he started out with was somewhat more prosaic in spec than the one you see here. “It was just a little AX Sport, so it had a 1.3 8v engine with a race cam, some induction and exhaust modifications and a lot of weight saving,” Manfred recalls.
There’s no doubt that this little car provided the ideal means for Manfred to cut his teeth in the world of ‘mountain racing,’ but there was no disguising its limitations, nor the fact that it was pretty much a clubman spec car. Manfred was keen to progress in the sport, but he was also aware that this would be costly and that he may as well utilise the experience he’d acquired by competing in the AX – which leads us neatly to this little Gallic monster. This car came into Manfred’s ownership midway through 2010, and it took just hours for him to begin disassembling and prepping it for a life of punishing hill climbs.
“It was a clean, low mileage shell, so perfect for the kind of thing I had in mind. There wasn’t any rust to speak of, so I was clear to jump in and start stitch welding the shell, strengthening and bracing the engine bay and the suspension points,” recalls Manfred.
He also took the wise (not to mention necessary) step of fitting a whopper of a roll cage, a welded in one that triangulates with both the front and rear strut tops, runs along the dash and criss-crosses the entire shell. Obviously a cage like this is primarily there for safety purposes (some of those German road courses climb to considerable heights, with sheer drops to match), but it also provides strength to the tinny AX bodyshell, something badly needed once the fibreglass doors, bonnet and boot are factored in.
This period of the build also saw Manfred address one of the major shortcomings of his previous AX, width.
“The old car was fairly stock looking. OK so we flared the arches a little to fit slightly wider wheels, but it still wasn’t that much, and it restricted the size of tyres we could run,” Manfred explains. There was no way that the new AX was going to want for mechanical grip, something that explains the massively flared arches front and rear. This car is almost comically wide, with more than a touch of Metro 6R4 about its silhouette (which is no bad thing in our book). Those arches have been painstakingly constructed from carbon fibre, with the fronts working perfectly with that ultra-aggressive, demonstrably effective front splitter. The rear end is dominated by that bi-plane rear wing, and again it’s hard not to make comparisons to Group B machines. “We tried to make the aero package as efficient as possible, but of course it’s a challenge when you’re working to a tight budget and don’t have a wind tunnel,” Manfred says.
Perhaps the most ambitious aspect of the AX’s aero kit is the flat floor and rear diffuser. This has been achieved through careful use of carbon fibre and Kevlar, and though it’s still a long way from the kind of thing seen in early 80s F1 cars, this DIY ground effect does provide a noticeable increase in the amount of grip available.
Propulsion comes in the form of a TU engine, but not the kind you’ll find in your average PSA product. This TU5JP4 1.6 16v was ‘liberated’ from a full-fat C2 Super 1600 rally car, meaning a fully forged bottom end, carefully worked over head, and a screaming rev limit of 9800RPM! The engine breathes through a set of 48mm KMS individual throttle bodies, while at the opposite side you’ll find a custom free-flowing manifold and a 70mm straight through stainless steel exhaust. Power is 243bhp, though there’s potentially more to come should a winter of development and fettling provide the results they are expected to.
“The jump in power and responsiveness over the old 8v engine is just night and day. It’s a lot more modern and allows us to compete against the other cars in the class, like the Corsa, the Golfs, Polos and Sciroccos.”
That manic 1600 engine is mated to an equally trick transmission, with spec highlights including a Drexler six-speed sequential gearbox and LSD, heavy duty, tarmac-spec driveshafts, and Xsara hubs. When coupled with the KW V2 coilovers, rose-joints and reinforced suspension mounting points, it perhaps shouldn’t be that surprising that this little Citroen is more than capable of handling all that NA shove.
Massive brakes aren’t actually as important to hill climbing as you might think (let’s face it, you’re not going to excel in the sport if you’re stamping on the brakes while going uphill), with many of the fastest cars actually running tiny motorbike brakes on the rear axle in an effort to save weight. Of course this AX weighs pretty much nothing at all, but a desire to keep it as usable as possible means than Manfred runs relatively large 310mm discs with ATE four-pot calipers, plus competition spec fluid, pads and braided discs. Suffice it to say that this is one hatch that really can ‘stop on a dime.’
“It’s not as powerful as some of the other cars out there, but because it’s so light I can brake very, very late, sometimes not at all. That’s how I make up time,” chuckles Manfred.
Those stoppers are housed inside seriously cool BBS split rims, 10x15in at the front and a massive 10.5x15in at the back. (hence the need for those equally beefy arches) Tyres vary depending on the conditions, but most of the time Manfred runs super sticky Avon track slicks front and rear.
The inside is dominated by that mammoth roll cage, and there’s no way you’d mistake this for anything other than a specialised, full-fat competition machine. It’s certainly a far cry from Manfred’s first AX! Creature comforts are thin on the ground, though you will find a Konig carbon fibre bucket seat, a floor mounted pedal box, a ten gallon fuel cell with twin pumps, a brake bias valve, and a sophisticated AIM data logging system with a built in camera (there’s no point putting in banzai times if you can’t see the results for yourself at a later date!).
The AX first turned its wheels in anger at the start of the 2012 season and proved itself to be immediately competitive and reliable, thanks in no small part to the sheer number of brand new components that’ve been used throughout. Manfred has been more than able to hold his own against some cars that, on paper at least, look to have the beating of the AX, and in fact he emerged as the overall winner of his group. There’s still more performance to come though, with that super 1600 TU engine currently running at a fairly moderate spec and a few revisions to the aero package in development, so we expect a lot more lunacy in the near future!
Super 1600 race engine was liberated from a C2 and is currently at 245bhp, with more to come over the winter!
In a bid to increase grip Manfred fitted massive arches to accomodate huge slicks, and an extensive aero package was painstakingly crafted.
ENGINE: 1600cc #TU5JP4
16v Super 1600 engine with 48mm #KMS
individual throttle bodies on short manifold, fully forged internals, lightened and balanced crank, H-beam con rods, lightweight valves with double valve springs, custom profile camshafts, free-flowing head wrapped manifold, 70mm stainless straight through exhaust with side exit, standalone management, alloy header tank, alloy fan, Aerogrip braided lines.
TRANSMISSION: Drexler six-speed sequential gearbox and LSD, motorsport spec #Drexler
driveshafts, Xsara hubs.
coilovers, adjustable top mounts, rose jointed front end, strengthened suspension mounting points.
BRAKES: ATE four-pot calipers with 310mm fully floating discs all round, braided lines, competition pads and fluid.
WHEELS: Front: 10x15in three-piece #BBS
split rims, Avon racing slicks Rear: 10.5x15in three-piece BBS split rims, Avon racing slicks.
EXTERIOR: Stitch welded and braced Citroen AX body shell with carbon fibre doors, arches, skirts, splitter, spoiler, tailgate, bonnet and diff user, carbon-kevlar under-body panel.
INTERIOR: Multi-point #FIA
compliant roll cage, Konig carbon fibre bucket seat, AIM data system with onboard camera, OMP wheel on a snap off boss, ATL 10l fuel safety cell with twin pumps, fire suppression system, floor mounted pedal box, Plexiglas windows, remote engine shut offs.
“We tried to make the aero package as efficient as possible, but of course it’s a challenge when you’re working to a tight budget”
Hillclimbing is massive in Germany, so much so that it spawns monsters like this AX!
Interior is pure focused race car.