420 S - 1985 to 1987
Introduced contemporaneously with the 420, the sportier 420 S saw its power output raised by 25 HP to reach an already impressive 210 HP. This increase was due in great part to the use of a twin air-to-air intercooler, the presence of which was given away by two NACA ducts on the bonnet.
In practice, the model was very similar to the Biturbo S, only with four doors and the implied longer wheelbase. Hence the body followed the same treatment with a two-tone paint scheme (silver or red over grey lower-body) and blacked-out chrome trim. The interior was trimmed by hand in red leather, deployed on the central part of the seats, centre console, dashboard and armrests.
254 cars were built before the model was upgraded with the Weber electronic injection system, thus becoming the 420 Si.
Technical data
| 0-60 mph | 0 to 100 km/h in 6.2 sec. |
| Bodywork | four-door saloon seating five |
| Bore and stroke | 82x63 mm |
| Brakes | discs all round, A.T.E. system (IH type) dual circuit, servo-assisted; two rear drum brakes for emergency and parking |
| Brakes front | |
| Brakes rear | |
| Chassis | monocoque steel construction |
| Compression ratio | 7.8:1 |
| Cooling system | water-cooled, centrifugal pump |
| Displacements (unitary) | |
| Dry weight | 2,590 lbs (1,175 kg) |
| Engine | 90° V6, light alloy block and head, Aluminum-Nigusil cylinder liners |
| Engine weight | |
| First race | |
| Front Tyres | |
| Front suspension | MacPherson struts, dual-rate telescopic dampers, coil springs, anti-roll bar |
| Front track | 56.77 in. (1442 mm) |
| Fuel & lubricant | |
| Fuel feed | a single twin-choke carburettor, two IHI turbos, MABC (Maserati Automatic Boost Control), two air-to-air intercoolers |
| Fuel tank | 18.04 Imp. gal. (82 litres) |
| Gear ratios | |
| Height | 51.57 in. (1,310 mm) |
| Ignition | electronic ignition |
| Kerb weight | |
| Length | 173.23 in. (4,400 mm) |
| Length-Width-Height | |
| Lubrication | full-flow filter lubrication |
| Maximum power | 210 bhp at 6,500 rpm |
| Maximum torque | 25.8 kgm (187 lbs/ft) at 3,500 rpm |
| Model | 420 S |
| One mile | 0 to 1000m. in 26.9 sec. |
| Production dates | 1985-1987 |
| Production start | 1985 |
| Quarter mile | |
| Rear Tyres | |
| Rear suspension | semi-trailing rear arms mounted on a rear subframe, coil springs, dual-rate Bilstein gas telescopic dampers |
| Rear track | 57.20 in. (1453 mm) |
| Reduction | |
| Steering | rack and pinion (power assistance to order) |
| Timing gear | three valves per cylinder (two intake, one exhaust), twin overhead camshafts |
| Top speed | 135 mph (218 km/h) |
| Total displacement | 1,995 cc |
| Transmission | 5-speed ZF + reverse, rear-wheel drive and Sensitork differential, 3.73:1 ratio |
| Tyres | fr/rear 205/60 VR 14 |
| Weight distribution | |
| Wheelbase | 102.36 in. (2,600 mm) |
| Wheels | light alloy, 6.5" J x 14" |
| Width | 68.11 in. (1,730 mm) |

