The shifting sands of the World Rally Championship were at their least predictable in the mid 1980s, with the sudden, tragic canning of Group B at the conclusion of the 1986 season effectively forcing all associated with the sport to take several steps backwards in order to better assess the situation.
The WRC would soon embrace the Group A concept, a resolutely production-based formula and one which would remain the sport’s top tier for another ten years. The impact of this change in sporting direction was drastic, not least as it left Europe flooded with would-be stage rally cars, all now effectively useless, banned from the sport they were designed to compete in, and, by the standards of the day, brimming with cutting edge technology.
The sheer number of former Group B rally cars now floating about Europe was breath taking and it wasn’t long before many were being repurposed for use in the increasingly popular sport of Rallycross. Indeed, within 12 months of the FIA’s ban officially coming into effect European Rallycross grids were packed with exotic machines, each the product of countless millions of manufacturer money: S4s, Quattros, 6R4s, RS200s and T16s, all could be found flying across snatches of asphalt and rutted gravel.
It takes something seriously special in order to stand out in such a crowd, and today’s Retropower Hero did just that; John Welch and his Astra GTE. Borne from GM’s own, short lived Group B/S programme, the largely self-built car proved more than able to hold its own against better funded rivals designed by the best the boffins from Audi, Peugeot and Lancia could muster.
The foundations of the car were laid out in the mid ‘80s when GM commissioned the construction of four Astra Mk2-based cars, each with a different engine and clear evidence of the degree of ambiguity surrounding rallying at the time. Two of the Opel versions contested the 1986 Paris-Dakar without success, another wound up in the company’s museum in Russelsheim, while the Vauxhall, the 4S (built for the stillborn Group S category), stayed in the UK.
What the quartet of Astras had in common, however, was an Xtrac four-wheel drive system. Mike Endean had pioneered the concept of all-wheel drive setups with the ability to adjust the percentage of torque sent to either axle some years earlier, and the system had been well proven in a number of high-profile rallycross cars, not least the Mk3 Escorts of Martin Schanche and Welch himself.
The real beauty of Endean’s system, the factor which had representatives from both Ford and Opel beating a path to his door, was that it had provision for torque to be toggled ‘on the fly’ by means of an alloy lever. Clicking it forward would engage the epycyclic centre differential in a basic 50:50 split (with conventional plate-type LSDs front and rear), perfect for powering out of corners and muddy hairpins. Pulling it all the way back would switch this to a 28:72 (front/rear), in turn allowing the car to be driven in a manner more frequently associated with a rear-wheel drive Escort.
Wind forward a few years, and Welch’s experience of driving Xtrac-shod cars came to the fore once again and made the prospect of using one of the now surplus to requirement Astras as the basis for a new rallycross monster a viable one. This being late 1986 and little dating faster than yesterday’s race car, Opel was only too happy to sell him one of the ex-Dakar cars, albeit with some help from Endean behind the scenes.
Three of the four Astras built were powered by variants of the Manta 400’s trusty 2.4 twin cam (the other, the one now residing in Opel’s museum, had a BDA turbo with the Ford logo ground off), and while a proven motor in its own right, it was never going to be powerful enough to hold its own against 650bhp T16s, Quattros and Deltas. Welch therefore commenced a development programme with Swindon Race Engines, one which would eventually see the Manta engine sleeved down to 2.1L, fitted with fuel injection, MBE management and, most impressively of all, a truly enormous F1 spec turbo, actually taken from a BMW ‘Megatron’ equipped Arrows chassis.
The result of all this homebrew engineering was, it must be said, spectacular. The now force-fed four-pot made a massive 650bhp at just under 2.0bar, though this of course could be pegged back to improve reliability and driveability.
The Xtrac system proved its worth time after time, evolving as the seasons went by and making the monstrous Astra a vaguely drivable proposition. The centre epicyclic diff’ was eventually configured to lock when under full boost, and, at the other end of the spectrum, open under heavy braking. This made Welch’s Astra a dizzyingly versatile bit of kit, able to launch like the proverbial scalded cat yet corner in a manner that would’ve been incomprehensible to a Group B Quattro driver just a handful of years previously.
The mix of Kevlar and carbon fibre panels used to cloth the Astra’s space-framed chassis ensured that it was also light and strong, the latter point put beyond doubt when, some years into his ownership, Welch crashed the car heavily. It was all but written off (and Welch had to search out another Astra to use as a donor), but the driver emerged unscathed.
There was no doubt that Welch’s creation was among the most popular rallycross cars of the time, which is all the more impressive when you consider the drama and providence of the cars it was sharing a grid with. Its first event was the last of the 1987 British Rallycross Drivers Association at Cadwell Park, and while ultimately forced to cede overall victory to Mark Rennison’s RS200 in the final, Welch had proved his point: the new car was able to live with the more established opposition, at least in Britain.
Sadly, both for Welch and rallycross fans across the board, the Astra was never as effective a proposition further afield and retired at the end of the 1992 season with a best ERC finish of 10thoverall. The car was then sold to Tommy Kristofferson, after which it was broken for parts and the Xtrac system used in his Audi S2.
Sadly though, it wasn’t all that successful, at least in the most high-profile series, the European Rallycross Championship. The Astra was a regular contender from 1988 to 1992, and while doubtless competitive it was never able to beat the most established opposition on a regular basis. It retired with a best place of 10thoverall.