Guide: All-In to Topple the T16 - a Historical & Technical Appraisal of the Lancia Delta S4
BACKGROUND
After a disappointing debut season in 1982, the Lancia 037 came good in 1983 by winning that year’s Driver and Manufacturer World Rally Championship titles.
The rear-wheel drive 037’s state-of-art Group B specification meant it just about had the edge over Audi’s four-wheel drive Quattro (the car that had cleaned up in 1982). However, when Peugeot and Audi introduced four-wheel drive Group B specials, the 037 was largely consigned to also-ran status.
1984 proved a chastening experience for Lancia when the 037 scooped just one WRC victory: the all-tarmac Tour de Corse. By contrast, Audi’s revamped Quattros bagged seven wins en-route to both titles while the 205 T16 (introduced mid way through the season) took three.
If Lancia wanted to win another World Championship, it was clear a new four-wheel drive Group B car was needed.
At the time, rallying had a profile to match Formula 1; the awe-inspiring Group B cars drew huge crowds and media interest was off the scale. Given Lancia was upholding Italy’s national interest, there was no question of quitting.
Lancia’s in-house competition department, Abarth, was thus tasked with creating the ultimate Group B rally car of its era.
A massive development programme was given the green light with a view to having a finished car publicly unveiled at the Turin Motor Show in October 1985. This would give the Martini-backed works team an opportunity to contest a couple of late season events prior to a full campaign in 1986.
For marketing reasons, Lancia instructed Abarth to develop a Group B challenger that mimicked the series production Delta. Peugeot had started the trend by designing the T16 to resemble their new 205 GTi, sales of which consequently got a massive boost.
Codenamed Abarth SE 038, the new Lancia would use a mid-mounted supercharged and turbocharged engine, plus of course, four-wheel drive.
It was officially titled the Delta S4 (Supercharged 4-wheel drive).
As Abarth did not have much experience with four-wheel drive, British firms Hewland and Ferguson were brought on board.
To homologate a competition version of the Delta S4, Lancia would ostensibly need to build 200 road versions within a twelve month timeframe. However, thanks to the FIA’s eagerness for an Italian challenger to rival the all-conquering 205 T16, it is widely believed that Lancia had produced substantially less than the required number of Delta S4s when homologation was approved on November 1st 1985.
CHASSIS
The new car, built in conjunction with Turin coachbuilder Savio, was based around a tubular chrome-moly alloy steel spaceframe reinforced with composite material. Aluminium alloy subframes were attached front and rear. At 2440mm, the wheelbase was 200mm longer than the outgoing 037. A 74-litre fuel tank was mounted up against the rear bulkhead.
Suspension comprised long-travel double wishbones with coil springs and hydraulic shocks (two per side at the rear). An anti-roll bar was installed at either end.
Abarth fitted hydraulically-assisted 300mm diameter ventilated disc brakes, aluminium-alloy single-piston Brembo calipers and Pirelli-shod 16 x 8-inch Speedline wheels all round.
ENGINE / TRANSMISSION
The Delta S4’s new lightweight Abarth-designed Tipo 233 ATR 18S inline four cylinder engine was developed specially for this application.
Mid longitudinally-mounted, it was twin charged to reduce lag and improve torque which would prove enormously beneficial on tight and twisty rally stages.
As suitably advanced electronics were not available at the time, the complex twin charge system relied on pneumatic actuators and release valves. Compressed air from the supercharger was sent to spool up the turbo which, combined with additional gases from the exhaust manifold, was further compressed by the vanes of the turbocharger. The combined forced induction was then sent through the inlet manifold and into each respective cylinder.
The 233 ATR 18S motor was a DOHC all-alloy unit with four valve head and dry-sump lubrication. Displacement was 1.75-litres so as to come in at under 2.5-litres when the FIA’s 1.4 multiplier for turbocharged motors was applied. This put the Delta S4 in the 2000-2500cc class which had a minimum weight limit of just 890kg. However, as the car lacked torsional strength, Abarth normally beefed-up the rally versions to between 950kg (for tarmac) and 1050kg (for gravel).
Overall displacement was 1759cc thanks to a bore and stroke of 88.5mm and 71.5mm respectively.
In road configuration, the S4 came equipped with a single KKK K26 turbo, an Abarth R18 Volumex supercharger and two air-to-air intercoolers. IAW 018 multipoint fuel-injection and electronic ignition were supplied by Weber-Magnetti Marelli.
With compression set conservatively at 7.0:1, the S4 Stradale developed 250bhp at 6750rpm and 215lb-ft at 4500rpm.
As the engine was ready before the chassis, Abarth shoehorned the twin charged motor into a crudely modified 037. This Frankensteinian creation was nicknamed ‘Mazinger’ after the famous Manga comic book character. The power and torque on offer proved a four-wheel drive platform was essential.
The Delta S4 ultimately incorporated both front and rear ZF limited-slip differentials plus a central Ferguson differential with viscous coupling. Typically, 30% of the power was sent to the front and 70% to the rear.
ZF also supplied the S4’s five-speed manual gearbox.
BODYWORK
Despite its thickset appearance, the Delta S4’s bodywork was refined during extensive wind tunnel tests.
Panels were formed in fibreglass. Clamshell front and rear body sections tilted forwards for access to the mechanical components.
Only the windscreen, front grille and tail lights were shared with regular Delta models. The twin headlights per side were sourced from the Fiat Ritmo.
Large side scoops behind the rear quarter windows fed fresh air to the turbo intercooler on one side and the supercharger intercooler on the other. A large adjustable spoiler was mounted on the roof ahead of which was an intake scoop for the engine and oil cooler. On the road version, the roof scoop was blanked off; additional cooling was unnecessary and the space was more effectively used to serve rearward vision.
Glass windows were used throughout.
INTERIOR
The S4’s cockpit architecture was completely new.
No less then seven gauges and a bank of warning lights were housed in the main instrument binnacle. A boost gauge was located between the 260kmh speedo and 9000rpm rev counter. Underneath were smaller read outs for fuel, water temperature, oil temperature and oil pressure. A clock and ammeter were positioned at the top of the centre console above a variety of switches and the trip computer.
Air-conditioning, electric windows and power-assisted steering were fitted as standard.
Suede alcantara was used for the knee roll, door centres, headliner and the handsome fixed-back seats that were unique to the S4. The three-spoke Abarth steering wheel also came with a suede rim.
WEIGHT / PERFORMANCE
Lancia quoted a weight of 1197kg, a top speed of 140mph and 0-62mph time of six seconds.
For comparison, the fastest ‘regular’ Delta of the period, the HF Turbo, tipped the scales at 1000kg, could hit 121mph and 0-62mph in eight seconds.
At 100m Lire, the S4 cost five times more than the previously range-topping HF Turbo.
OPTIONS
Aside from a limited selection of colours, few options were offered.
Most Delta S4s were painted red, but there were also white, silver, black and dark green examples. For the interior there was a choice of tan or red upholstery.
In addition, customers could have their car sent back to Abarth for a 300bhp engine upgrade, leather upholstery or Evoluzione-spec. wheels.
PRODUCTION
Although 200 cars ostensibly had to be lined up prior to the FIA rubber-stamping a Group B application, it is commonly thought that Lancia got the Delta S4 through having only completed around 150 units.
At the time, the FIA was desperate for a serious challenger to tackle the Peugeot 205 T16 heading into 1986. However, the long overdue Delta S4 had been seriously delayed by an array of technical issues surrounding its four-wheel drive system so, to enable Lancia to officially compete from November 1985, the rules seem to have been bent somewhat.
COMPETITION HISTORY
Having been given special dispensation to run in a number of low-key events since April 1985, the Delta S4 Evoluzione made its WRC debut on the season-ending RAC Rally in November where Henri Toivonen and Markku Alen took a dominant one-two finish.
Alen then finished second to WHO at the non-championship Bettega Memorial event in December.
Things got off to a good start in 1986 when Toivonen took victory at the season-opening Monte Carlo Rally, but the Lancias did not win again until round eight, the Rally Argentina in August, by which time Toivonen and his navigator, Sergio Cresto had lost their lives in a fiery accident at the Tour de Corse.
Following Peugeot’s scandalous exclusion from the Rallye Sanremo in October, the Lancia’s finished first, second and third led by Alen / Kivimaki, but this result was subsequently annulled at the end of the season following a protest from the French manufacturer.
As a consequence, despite victory for Alen / Kivimaki at the season-ending Olympus Rally, Juha Kankkunen was able to claim the Drivers’ championship while his Peugeot team had already done enough to win the Manufacturers’ title.
With Group B cars banned from major FIA-sanctioned events after 1986, works participation with the Delta S4 came to an end.
Text copyright: Supercar Nostalgia
Photo copyright: Lancia - https://www.lancia.com
