Guide: the Production-based WRC Era Begins - a Historical & Technical Appraisal of the Lancia Delta HF Turbo 4WD
Background
When the Lancia Delta was launched at the Frankfurt Motor Show in September 1979, no-one could have predicted this boxy five-door hatchback would go on to become the most successful rally car of the 20th century.
However, an unforeseen series of events during the mid 1980s meant Lancia’s ageing and hitherto uninteresting mid-range model got thrust into the limelight.
The circumstances surrounding the Delta’s journey to greatness lay in the unprecedented arms race that transformed rallying between 1982 and 1986.
New rules introduced for the 1982 World Rally Championship allowed manufacturers to homologate cars in much smaller numbers than before. Whereas prior to 1982, a minimum production run of 500 identical cars had to be manufactured over a 24 month period before the model could compete in the premier Group 4 category, the new Group B class required only 200 vehicles in twelve months.
This led to an onslaught of highly focused and increasingly extreme vehicles, the speed of which rose exponentially between 1982 and 1986.
Lancia had been the first out of the traps with a pure Group B creation; their mid-engined 037 Rally vanquished the opposition in 1983 after a troubled debut season in 1982.
Peugeot, Audi, Ford and Rover soon followed with the 205 T16, Quattro Sport, RS200 and Metro 6R4 respectively.
Group B survived into a fifth season before the category was outlawed at the end of 1986 following a series of driver and spectator fatalities.
By this time, Lancia’s second generation Group B car, the Delta S4, was developing in excess of 600bhp which, combined with lax crowd control at many events, was a recipe for disaster.
The carnage reached an unacceptable level and, in May 1986, the FIA decided Group B would be abandoned from 1987. It also froze any further car development for the rest of the ‘86 season.
To reduce speeds, the 1987 World Rally Championship would only be open to Group A cars. To qualify for Group A, a production run of 5000 vehicles over the course of a twelve month period was required.
This instantly killed off the low volume supercars that had reigned supreme during the Group B era.
From 1987, the World Rally Championship would be decided by vehicles with much humbler origins.
The FIA’s announcement left a lot of manufacturers high and dry but fortuitously, Lancia had launched a revamped version of their top-of-the-range Delta HF Turbo in May 1986.
In addition to an engine enlarged from 1.6 to two-litres, the face-lifted car most significantly featured four-wheel drive making it an ideal platform for the Group A era.
Chassis
The new HF Turbo 4WD was based on the Delta’s steel unibody platform.
It employed fully independent suspension with MacPherson struts at the front and double transverse arms at the rear. Dual rate dampers and helicoidal springs were installed along with anti-roll bars at either end.
Damper rates, front and rear toe-in and the relative angle between the springs and dampers were tailored specifically for this latest application.
Disc brakes were fitted all-round along with new Pirelli-shod 14 x 5.5-inch Cromodora alloy wheels.
The permanent four-wheel drive system split 56% of the torque to the front axle and 44% to the rear. A complex arrangement of three separate differentials was used to maximise traction.
Engine & Gearbox
Originally designed by Aurelio Lampredi, Lancia’s dual overhead camshaft inline ‘four’ featured an eight-valve light alloy cylinder head, cast iron block and counter-rotating balancing shafts.
Whereas earlier Deltas had only used engines of up to 1.6-litres, the HF Turbo 4WD got an upgrade to the two-litre engine from the Thema Turbo IE. This unit displaced 1995cc thanks to a bore and stroke of 84mm and 90mm respectively.
With compression set at 8.0:1, Weber IAW engine management and a Garrett T2 turbocharger set at 0.9 bar, it produced a peak power output of 165bhp at 5500rpm.
Overboost acted on the wastegate valve when hard on the gas which temporarily increased the turbo pressure and helped to generate a peak torque rating of 210lb-ft at just 2750rpm.
Transmission was via a five-speed gearbox.
Bodywork
Some of the cosmetic features debuted on the HF Turbo 4WD previewed the mid-life facelift that would be applied to the entire Delta range. Most obvious was the re-profiled front bumper panel with integrated fog lights. Additionally, the aluminium front grille surround had its side sections angled inwards which meant the headlights also had to be re-shaped.
For the HF Turbo 4WD, single headlights per side were switched to a pair of circular lenses that mimicked the Delta S4. This distinctive look was applied to all subsequent Delta homologation specials as well.
While later iterations also benefited from handsome flared wings to cover their wider wheels, the HF Turbo 4WD used the standard Delta’s comparatively narrow fenders.
In addition to its modified front end and different wheels, Lancia’s new top-of-the-range Delta could be identified by a twin pipe exhaust, discrete HF 4WD badges and pin striping down each flank and across the tailgate.
Interior
Internally, the cockpit received an updated dash, instrumentation, switchgear and centre console.
The seats were now trimmed in grey fabric with multi-coloured velour centres to match the door panels.
The black plastic dash featured an integrated binnacle directly behind the three-spoke steering wheel. It housed a large speedometer and rev counter, in between which were a series of warning lights and smaller read outs for turbo boost, battery amps, fuel and water temperature.
An additional pair of smaller gauges (for oil pressure and oil temperature) were housed at the top of the central control panel along with a schematic warning light display. The rest of the switchgear, along with the audio system, was located just below.
Electric windows were standard at the front but not at the rear.
Weight / Performance
Lancia quoted a weight of 1200kg, a top speed of 128mph and 0-62mph time of 6.6 seconds.
The weight distribution of 63% front and 37% rear belied this latest Delta’s handling prowess which was something the subsequent ‘Integrale’ variants would also become legendary.
Production
Following its launch in May 1986, production continued until 1987 by which time 5298 examples had been completed.
Group A Homologation was granted on January 2nd 1987.
That year, the HF Turbo 4WD won nine of the 13 World Rally Championship events.
in 1987, Lancia easily secured the Manufacturer’s Championship; the Italian team’s 140 points massively outscored works outfits from Audi (82), Renault (71), Volkswagen (64), Ford (62) and Mazda (52).
Lancia’s Juha Kankkunen (100 points), Miki Biasion (94) and Markku Alen (88) also took first through third in the Driver’s Championship.
Unlike Group A circuit racing where runs of 500 Evolution variants were permitted to homologate new parts, rally regulations had no such concession.
Instead, the rules stipulated that 5000 new cars had to be produced every time upgrades were made to the homologated specification.
To that end, Lancia replaced the HF Turbo 4WD with a new range-topping HF Integrale for 1988.
Text copyright: Supercar Nostalgia
Photo copyright: Lancia - https://www.lancia.com
