The Mini is no stranger to rallying but very few have ever hit a special stage with the presence of this wide-arched, Vauxhall-powered Rover Mini Cooper SPi created by Dutch race and rally preparation specialist Frans Verbaas. Based in Oud-Beijerland, near Rotterdam in southern Holland, Verbaas Preparations has been specialising in building, developing and running rally cars for clients for over 20 years and the Mini is the latest in a line of world class cars to have come from their company headquarters over recent years.

“The business has got bigger over the years,” says Frans, “We’re now preparing a (Mitsubishi) Evo X car for a customer, and we’ve also built Lancias, Sierras, Imprezas and Escorts for people who want them. But the Mini is for me.” The company has recently been awarded the Dutch franchise for Citroën’s C2 R2 rally car, and has a continuous list of other projects on the go.

But it was with Minis that the company cut its rallying teeth. Frans’s father owned a Mini dealership and ran a sideline business in hire cars and Minivans in the 1960s and ’70s. Frans learnt to drive in a Mini and his first rally car was, naturally enough, a Cooper S 1300 which he built with the help of his dad and brother to compete in local rally sprints and other events. Frans switched to an Opel Astra in 2002 when British rally preparation firm BTR, headed by Tim Ashton, sold off its stock to make room for its expanding Mitsubishi Evo and FTO business. BTR Prep, based in Castleford, Yorkshire was charged with building cars and supplying technical support staff and technicians for Opel Team Belgium’s rally team between 1990 and 1995 — and had won the 1993 F2 World Championship with Bruno Thiry and its Group A cars. BTR Prep also had considerable success in Russia and Turkey with not only the Astra F2 kit car but also its Group N production class cars, so when the company decided to get rid of its Astra cars and parts, Frans stepped in and scooped up as much as he could.

Having run various Astras in numerous rallies and rallysprints in Holland, Belgium and the UK, Frans felt the need for a challenge and a return to his roots. He had also twice
competed in the Barbados Rally Carnival with Astras, first a Group N GSI in 2003 (DNF) and then an F2 kit car (fifth in class, 27th overall) — and said the all-inclusive regulations, coupled with the island’s hospitality, meant he wanted to return with a car that the motorsport-mad locals would appreciate.

Hybrid planning
With a collection of around 20 spare Mini bodyshells stored around the company’s 5600-square foot workshop (equipped with lathes, milling machines, damper dynos — and everything else required to produce world class rally cars) and a stack of Astra rally parts on hand, it didn’t take Frans too long to start formulating plans for his hybrid rally car. He began by measuring the engine bay and chassis of a 1993 Mini Cooper SPi that had been lying dormant under a dust sheet for several years and calculating what needed to be done to incorporate as much of the Astra as he possibly could.

There was never any doubt in Frans’s mind about using the Astra engine in the Mini. The C20XE is one of the most reliable in motorsport, and is a far cheaper way of developing sensible levels of power than building a full, race spec, A-Series engine. Frans also considered fitting a race prepared 1600cc GM engine and competing in a lower class, but decided against it. “The idea was to have a high revving, say to 9000rpm, 1600cc engine that made about 220bhp,” says Frans, “but to make such an engine costs £10,000, and there is a lot of driving in traffic and hills between stages in Barbados, so this type of engine is not very good for that. It’s not so reliable.”

The Group N 2-litre C20XE fitted with throttle bodies, however, is a largely standard engine that develops, according to a post Rally Barbados rolling road session, 183bhp at the wheels at 6-6500rpm — with a potential 30bhp more on tap at around 7750rpm. All without the prohibitive cost of attempting to eek every ounce of power out of a smaller, finely-focused engine. Frans reasoned that adapting the car to accept the Astra’s front subframe was a better way of incorporating the engine, gearbox and suspension into the Mini than configuringhis own. It meant that he could use parts he already had and was familiar with without having to replace them with bespoke parts and having to restock the workshop or service van. The expensive Pilbeam uprights could be used, so too could the Astra kit car’s brakes, wheels and tyres — and the driveshafts were exactly the same length. “I thought about it for a long time,” Frans explained. “The important thing for me was that the car still looked like a Mini. I didn’t want to have a Clubman front on the car just to make the engine fit: it needed to look as much like the original car as we could.”

They started by cutting out the Mini’s rotten floor and redundant firewall and assembling the bodyshell on a jig to help support it during the transformation. New floors were sourced through Mini Spares and welded into place, while the new firewall was constructed to accommodate the Works Astra’s front subframe, engine and transmission. Frans fitted his own bespoke rollcage welded from lengths of steel tubing and triangulated for optimum strength, and positioned the front struts so that the topmounts poked through the tops of the wings and are located by the car’s rollcage. This was done partly through necessity: the Astra’s subframe and suspension is a little wider than the Mini is able to accommodate without compromising suspension geometry — and partly through good design, because it offers far more suspension travel than standard. It also means Frans can quickly change suspension geometry settings or dampers should he need to, without opening the bonnet.

Built to order
Verbaas is a Koni stockist (his workshop is 500m from the Koni factory), so used the company’s dampers, built to his own specifications, at either end of the car. The rear A-arm suspension was modified to produce a perfect balance of stability and grip. The car was “70 per cent complete” by the time he loaded it up with parts and brought it to the UK for shipping out to Barbados. Engine mapping was completed in Surrey by Steve Broughton at SBD on the way to Portsmouth where it was loaded on to a Geest liner and shipped to Barbados. Finishing touches to the set-up were done during a few test sessions on the island prior to the event.

“Like anything, you think you have lots of time but, in reality, you end up getting it close to where you want it and spend time when you get there making sure everything is
right,” explains Frans. “I must say, it felt pretty good out of the box, and we had no real problems on the rally, so second in Group B (see sidebar) was pretty good. We found out later that I was shifting a bit too early, so there is more power available, but the balance was good and the car was very fast,” he said.

Other little niggles are relatively easy to sort out. Inlet temperatures are around 55 degrees C which Frans says is a little too high. The bonnet louvres were designed to draw hot air away from the engine bay, but they didn’t work as well as expected either. “We didn’t have time to make a carbon box for the inlet, so once we do this, that should bring the temperatures down about 10-15 degrees,” he says. The roof vent flap didn’t work as well as he’d hoped either: the angle of the windscreen means the airflow shoots straight over it, and the only thing that flows into the car is dust. Frans has already got a solution for that in place.

That said, Frans was exceptionally happy with the way the car performed on its debut outing. Second in class behind local driver Greg Cozier in his Vauxhall-powered Exige.
“We have some work to do with the dampers and suspension,” says Frans. “The first day’s rougher roads were very hard on the suspension so we probably need to go with a softer set-up to let the car drift a little more. It was better on day two with the smoother roads, so I think we have the balance right for then.”

Frans intends to be back in Barbados in 2010 to better his result this year. “We’ve made a few changes and we should be a lot faster next time.”