Track test: Pikes Peak Peugeot 405 T16

Aiming higher

Instead of Britain’s pastoral uphill sprints, the Americans can indulge hill-climbs of Continental grandeur. So it is fitting that Europeans such as Peugeot and Audi have become fascinated with the commercial prestige which accrues from winning the USA’s annual 12.4-mile Pikes Peak contest.

Last year Audi and Walter Rohrl marshalled the forces of a 598 bhp 2.1-lire Quattro Sport S1 development to set a new record. This year Audi was absent, but Peugeot put its engineering might and the loose-surface driving skills of Ari Vatanen and Juha Kankkunen to effective work. The two Fins finished first and second; they also set a new record, just under 70 mph average, over sandy and stony trails, despite nature’s stormiest tantrums.

The 405 Coupé outline of this competition Peugeot is not yet available to the public, but much of the transverse mid-engine and all-wheel-drive componentry beneath was made familiar in the double World Rally Championship 205 T16s of 1985-86.

The aluminium four-cylinder has the usual dohc and 16-valve layout of contemporary performance units, yet its 520 bhp at 700 rpm and 470 lb ft of torque at 4500 revs are far from routine. The power-unit was developed from the 1775cc unit of the rallying 205s, displacing 1905cc via an elongated stroke; it now measures 83mm x 88mm. A static 7:1 compression ratio is used in association with a Garret AiResearch turbocharger to boost pressures to maximum of 3-bar.

This compares with the 1987 power-unit, which originally developed 400 bhp on 2.2-bar boost, plus 362 lb ft of torque, all for flexible power to a geared 137 mph upon the Paris-Dakar-style events which Peugeot now contest.

I would estimate the car I drove had similar power statistics to that 1987 development 405, because it was limited to 2-bar boost, to avoid triggering the water-injection system which operated at pressures above 2.8-bar for Pikes Peak in 1988.

New transmission features included the company’s own TJ six-speed gearbox and the use of carbon-fibre materials to save 7kg over a conventional clutch friction disc.

The four-wheel steering system is similar in action and principle to the mechanical system adopted by Honda for the Prelude coupé. That means a transfer shaft fore and aft, activating the rear wheels to a counter-steering pattern beyond a three-quarter turn of lock.

Unlike the Honda, the Peugeot’s rear wheels do not follow the arc of the fronts, instead remaining neutral until that three-quarter turn of lock is applied, then only moving 3deg for every further degree of front wheel movement. Interchangeable cam profiles in the rear steering box mean that such characteristics can be changed rapidly to take account of different wheelbase, roads, adhesion levels and tyre sizes. We had 10.6in wide, 45% low profile rear Michelins installed, this 405 employing 16in diameter Speedline wheels.

Peugeot successfully aimed at a similar kerb weight to that of the 11.8in-shorter wheelbase 205 T16. A total of 880kg was achieved, using the now usual Kevlar and composite materials for the lift-off body panels and the imposing spoilers.

Overall length was just over 167in, but the extended wheelbase accounted for the disproportionate 113.7in, thus endowing this 405 with a fine ride, plus more progressive handling than either the mid-engined 205, or the front-drive 205 GTi.

Enclosed within the tubular steel and folded sheet-metal framework of the monoposto LHD Peugeot, one is certainly conscious of mortality. The ominous smell of petrol lingers on after they top up the 50-litre underfloor reservoir within, and an RACMSA scrutineer would probably not approve the unshielded battery sharing the fume-laden compartment.

The clutch is of the embarrassing in/out variety, but the gearbox is perfect compensation. The pattern is that of most rallying six-speeders, with fifth facing sixth across the gate and an extension to the right which will find reverse. Gear selection is so free from mechanical clashes that you immediately forget synchromesh is absent, recalling only the unsynchronised speed of changes (without the obstructions that even the best roadgoing gearboxes ultimately exhibit) and free to admire the closeness of the ratios.

Boost multiples rapidly beyond 4000rpm, with startling acceleration delivered through 4WD grip. This is 1.9-litre romps to the 8000rpm cut-out in the first five gears on the short straight provided, then exceeds 7600 rpm in sixth with an exhilarating escalation in sound levels from that mains-drainage exhaust orifice.

Peugeot’s transverse mid-engine layout and double-wishbone suspension with 4WD was unmatched in Group B days for poised rallying traction. The 405 lifts such abilities to another astonishing plateau. The 4WS system seems to speed the 405’s turn into low-speed corner, but the initial loose-surface understeer was hard to overcome.

Once the 405 was sliding it could be persuaded to large angles of opposite-lock motoring, but that is not its natural stance: the 405 seems to slide pretty evenly at either end under full power on a loose surface; something of a surprise given the unequal power-distribution of one-third front, two-thirds rear. Those extrovert aerodynamic appendages and rear ground-effect tunnels are set to exert maximum assistance between 62 and 112 mph. Maybe the driver’s impressions are coloured more by aerodynamics than mechanical underpinnings?

AP four-piston callipers and ventilated dis-brakes remained constant, even with hard treatment at low air-speeds. At our rallycross circuit pace, the complete car was viceless in its handling and immense traction, despite the rousing turn of full-boost speed. JW