Maserati Biturbo

History

When Alejandro de Tomaso acquired Maserati in 1976, he had ambitious plans for the marque. His plan was to combine the prestige of the Maserati brand with a sports car that would be more affordable than the earlier high-priced models that had traditionally made up the Maserati range. In fact, Maserati ceased making supercars like the ones developed under Citroën ownership altogether, like the Bora and Khamsin.

The Biturbo was initially a strong seller and brought Italian prestige to a wide audience, with sales of about 40,000 units. Sales figures fell in subsequent years. De Tomaso also used another of his companies, Innocenti, to produce Biturbo body panels and also to provide final assembly of Biturbos. De Tomaso later sold Maserati to Fiat, who grouped the company with their erstwhile rival Ferrari.

The Biturbo is number 28 in the BBC book of "Crap Cars" and in 2007 was selected as Time Magazine's worst car of 1984, although they ranked the Chrysler TC by Maserati as a "greater ignominy".

The Biturbo competed unsuccessfully in the British Touring Car Championship in the late 1980s, the European Touring Car Championship and the World Touring Car Championship (1987).

Gandini's first restyling

Between 1987–89 a facelift was phased in, which helped to soften the sharp bodylines. The redesign included a taller and more rounded grille with mesh grille and bonnet, aerodynamic wing mirrors and 15" disc-shaped alloy wheels, now mounted on 5-lug hubs. Some models received the wraparound bumpers with integral foglights and the deep sills introduced with the 2.24v.

Gandini's second restyling

In 1991 the entire lineup was restyled for a second time, again by the hand of Marcello Gandini; the design features introduced with the Shamal were spread to the other models. Gandini, the Shamal's designer, developed an aerodynamic kit that included a unique spoiler at the base of the windscreen hiding the windshield wipers, a rear spoiler, and side skirts. The new two-element headlights used poliellypsoidal projectors developed by Magneti-Marelli. Inset in body-colour housings, they flanked a redesigned grille, slimmer and integrated in the bonnet; the 1988 bumpers were adopted by all models. The 15" disc-shaped alloys were replaced by new 16" seven-spoke wheels, with a hubcap designed to look like a centerlock nut. The second facelift was referred to as nuovolook.

Specifications

The cars in the Biturbo family were of unibody steel construction, with a conventional layout of front-longitudinally mounted engine and gearbox. Suspension was of the MacPherson strut type upfront and semi-trailing arms at the rear, with coil springs, double-acting dampers and anti-roll bars on both axles. The differential and rear suspension arms were supported by a subframe.

Engines

The Maserati Biturbo was the first ever production car with a twin-turbocharged engine. It also featured the first production car engine with three valves per cylinder. The aluminium 90-degree SOHC V6 engine was roughly based on the 2.0 L Merak engine, itself based on earlier V8 Formula One Maserati engines, designed by Giulio Alfieri (1924–2002). The 2-litre version featured wet aluminium sleeves coated with Nikasil. The last street version featured over 150 hp/litre and 140 ft·lbf (190 N·m)/litre torque.

In Italy new cars with engine displacement over 2000 cc were subjected to a 38% value added tax, against 19% on smaller displacement cars. Therefore, throughout the Biturbo production life there were both two-litre models aimed mainly at the domestic market and "export" versions, initially with a 2.5 L V6. The carbureted 2.5 L engine produced 185 hp (138 kW) and 208 lb·ft (282 N·m) of torque in North American spec and slightly more elsewhere.

In 1984 and 1985, the 2.5 L V6 models utilized a single Weber DCNVH carburetor under a smooth aluminum alloy plenum fed by twin IHI turbo chargers (one per each bank of 3 cylinders). Maserati, US dealers, and sports car enthusiasts began experimenting with intercoolers for which many variants were fitted and mutually endorsed by Maserati. Intercoolers included air-to-air (two variants: top mounted assembly which was not as efficient as the separate side-mounted versions) and water-to-air all produced by Sparco. In 1986, the 2.5 L V6 models switched to a Weber 34DAT carburetor which was proven to be less efficient and more problematic to maintain than the Weber DCNVH used previously. On initial viewing of the 1986 Biturbo engine bay, the aluminum alloy plenum is finned with a slightly different footprint and the intake manifold was specific for that model. Similar experimentation with intercoolers and placement continued through 1986 models. However, the side-mounted water-to-air intercooler became the standard variant utilized until late 1986 / early 1987 when the intercoolers were placed, by Maserati factory, outside the engine bay located in front of the radiator where they remained throughout the remaining models in the Maserati Biturbo family tree.

Fuel injection was fitted in 1987 raising power to 187 hp (139 kW).

In 1989 the enlarged 2.8 L engine bumped power to 225 hp (168 kW) and 246 lb·ft (334 N·m) of torque for North America and 250 PS (184 kW) for Europe.

A V6 1996 cc DOHC 36-valve (6 valves per cylinder) engine was developed but never manufactured.

Biturbo

The Biturbo proper was a two-door 2+2 coupé, introduced in December 1981. It was powered by a twin-turbo V6, producing 180 to 205 PS (132 to 151 kW; 178 to 202 bhp). The Biturbo name disappeared when the car was significantly redesigned in 1988. After 1994 the two-door car was again significantly reworked and became the Ghibli.

In July 1983 Maserati launched the sporting Biturbo S, for the Italian market only. Power was up 25 PS to 205 PS (151 kW; 202 bhp) at 6500 rpm, thanks to increased turbo boost and twin intercoolers fed fresh air by two NACA ducts in the bonnet. The chassis was updated too with lowered suspension and new, wider 6½Jx14" magnesium alloy wheels, painted gunmetal grey with silver center and lip. The S was recognizable by its black mesh grille and the external trim (grille frame, headlight housings, window surround and Maserati badges on the C-pillar) finished in a dark bronze shade instead of chrome. The customer could only choose between two paint schemes: silver or red, both paired to the lower half of the body in contrasting metallic gunmetal grey. That same year the 2.5-litre Biturbo 2500 or Biturbo E (for Export) was also introduced, and was joined some twelve months later by the Biturbo ES with 205 or 196 PS (151 or 144 kW; 202 or 193 bhp), respectively in European- or catalysed US-specification. In 1985 all models received updates and were renamed Biturbo II, Biturbo S II and Biturbo E II. The cylinders were now Nikasil-coated, a more capacious fuel tank was fitted and a Sensitork limited slip differential replaced the earlier Salisbury clutch-type one. The second series Biturbo was recognizable by its new 6"Jx14" wheels similar in design to the Biturbo S's; the S II wheels had fully painted faces, without the silver center.

1986 brought a major change: carburation gave way to Weber-Marelli fuel injection, and the domestic models became the Biturbo i and Biturbo Si. Power increased across the range, albeit at some loss of throttle response. The original square instrument cluster (from 1983 - 1985) was changed in 1986 one with a rounded shape. The intercoolers were moved from under the bonnet to a front-mounted position directly behind the grille, making the NACA ducts on the Si's bonnet merely decorative. In 1986 an Italy-only special edition of the Si called the Biturbo Si Black arrived, whose main feature was of course a black on metallic grey livery. 105 were made until 1988. Performance was the same as for the regular Si. In 1987 Maserati launched the final car to wear the Biturbo badge, the 2.5 litre export market "S" model Biturbo E Si.

222

In 1988, with the coupés being restyled, the Biturbo name was dropped in favour of 222—meaning 2-door, 2-litre engine and 2nd generation. The car carried all the visual clues of Gandini's first facelift, with a more rounded grille and bonnet, different wing mirrors and rear spoiler. The engine size of the 222 E export model grew from the Biturbo's 2.5- to 2.8-litres. A mixed velour-leather interior was standard on the domestic models, while export markets got leather upholstery as standard.

1990 saw the arrival of the 2.8 L 222 SE, heir to the Biturbo ES. It inherited the latter's limited paint finish availability (red, silver or black) and the dark trim and grille, while modern aprons and side skirts (blacked out as well) came from the 2.24v. After just a year the 222 SE was replaced by the 1991-restyled 222 SR; the SR offered adaptive suspension as an option. Simultaneously the very similar 222 4v. joined the lineup; it was a 222 SR with a 2.8 L four-valve engine, the first DOHC car in the direct Biturbo E lineage. It used wider, 16" 7-spoke wheels.

2.24v.

In December 1988 Maserati unveiled the pinnacle of the two-litre line: the 2.24v., powered by the new four-valve head engine. The 2.24v. debuted the more modern wraparound front and rear fascias with integrated foglights, and deep side skirts. It was also distinguished by the 14" disc shaped alloy wheels, black grille and trim treatment, rear deck spoiler and lower body two-tone paint. The bonnet was adorned by two reversed NACA ducts to extract hot air from the engine bay, as on the Karif. In 1991 Gandini's restyling transformed the 2.24v. into the 2.24v. II. The new series cars was fitted with a catalytic converter, and got Meccanica Attiva suspension on all four wheels as standard. By 1993 production ceased.

Racing

The Maserati Racing (Tipo 331) was a more sporting variant of the 2.24v. with a higher power output, and was meant as an intermediate model underneath the more aggressive Shamal. It was first revealed to the press in December 1990, and built from 1991 to 1992 in only in 230 copies for the Italian market only. Later, several units could be found exported across Europe (France, Sweden, Denmark, Germany and the Netherlands); limited documentation was available, which made homologation in some countries (still) a huge administrative challenge.

In the chassis the lowered, electronic KONI shock absorbers allowed to adjust damping on four settings, allowing for comfort or road handling at the flick of a switch. This is combined with a manual five-speed gearbox from Getrag and a limited slip differential "Ranger" from Maserati but suspected to use Quaife technology. The choice of colour of the Racing was limited to red or black. Inside, the only change was the paneling, painted dark grey (carbon fiber grey) instead of being wood trimmed.

Combined with new settings on the two engine controllers from Magneti Marelli, in charge of the ignition, the fuel injection and the turbo boost management, this allowed the power to increase to 283 hp (211 kW; 287 PS) at 6250 rpm with a specific output 142 hp/l. The torque is 37.3 kg·m (365.8 N·m; 269.8 lb·ft) already at 3500 rpm, peaking at 38.1 kg·m (373.6 N·m; 275.6 lb·ft) at 4250 rpm. This engine is coded AM 490 in the Maserati engine reference book. The engine has been made compatible with lead-free gasoline. Induction consists of two IHI water-cooled turbos with two air-to-air intercoolers. Changes from the 2.24v's engine include a new, lighter crankshaft, new exhaust valves (sodium filled for improved heat dissipation), new combustion chambers, new lighter conrods, new lighter forged aluminium pistons, and new IHI turbochargers.

The saloons (Tipo AM332)

Two years after the Biturbo's introduction a four-door version was unveiled. In comparison to the coupé, the saloon sat on a 8.6 cm (3 in) longer wheelbase and had a more pronounced rear overhang. While keeping a family feeling with the rest of lineup, only the nose and bonnet were shared between the equivalent two- and four-door models; all the bodywork from the A-pillar back is specific to the saloons. The weight penalty for the saloon is about 100 kg (220 lb). Most of the four-door Biturbos have slightly less power than their two-door counterparts, due to the different routing of the exhaust system.

420 and 425

The first four-door Biturbo introduced was the 425 (1983–86), equipped with the "export" 2.5 litre engine. In 1984 the 425 (along with the two-door models) received a new dashboard. Two years later a two-litre version of the 425, the 420 (1985–86), was added for the domestic market, together with the more powerful 420 S. The 420 S sported improved handling, the twin intercooled engine and the same aesthetic accoutrements of the Biturbo S: dark finish trim, two-tone paint, two-tone wheels and NACA ducts on the bonnet, delivering fresh air to the intercoolers. Like their two-door siblings in 1986 the saloons were updated with the Weber fuel injection, thus spawning the 425 i (1986–89), 420 i (1985–87) and 420 Si (1985–87). The latter featured a somewhat more restrained styling than its predecessor.

430

In 1986 Maserati launched the high-performance 430 (1986–94), the flagship of the saloon range, which debuted the largest 2.8 litre version of the Biturbo engine. The 430 was distinguished by 15" 5-lug disc alloys and a more rounded grille and hood, that later found their way to the rest of the lineup with the first 1988 facelift. The 430 was luxuriously appointed as a true gran tourer, with standard leather upholstery and walnut veneered steering wheel rim, dashboard, door panels, gear shift knob and handbrake lever. 1991 saw the introduction of the restyled 430 4v. (1991–94), powered by the latest 24-valve engine – as the "4v." suffix implied. As the top of the range 2.8 L saloon the 430 received the full aerodynamic package, including a discreet spoiler on the trailing edge of the bootlid. The regular 430 was updated too (gaining new bumpers) and remained on sale alongside its four-valve sister.

422

As the Biturbos were replaced by the 222s, the 420s gave way to the 422 (1988–92). The 422 was basically a 420 Si with the 1988 restyled grille, wing mirrors and wheels.

4.24v.

The 1990–92 4.24v. was the four-door companion of the 2.24v.. This new subfamily of the Biturbos paired Maserati's state-of-the-art four-valve 2.0 L V6 with the new Meccanica Attiva suspension. The 4.24v. also adopted all of the exterior trappings of the 2.24v., including black trim and grille, black deep side skirts and a small spoiler on the boot. In 1991 the 4.24v. was subjected to the restyling alongside the rest of the range, becoming the 4.24v. II (1991–93). Catalytic converters meant power was down a little in comparison with the first series.

4.18v.

This Italian-market only model was launched in December 1990. It was very similar to the 422, but used the three-valve per cylinder heads. It was the first Biturbo to feature ABS as standard. With 77 examples made it is the rarest in the entire Biturbo family.

The spyders (Tipo AM333)

The convertible Biturbo was designed and assembled by Zagato in Milan. It was Zagato's first work for Maserati since the A6G/2000 of thirty years earlier. Embo of Caramagna was first commissioned to develop a four-seater cabriolet version of the Biturbo, which was shown at the April 1982 Turin Auto Show, but their proposal never made it to production.

The Spyder was built on a 2.4 metres (7.9 ft) wheelbase, some 11.4 cm (4 in) shorter than the coupé's. Still, since it is a strict two-seater with folding rear seats, the luggage space is larger than in the original Biturbo. It was on this short chassis that the sporty hardtop Karif was later developed. Overall 3,076 were built over a ten-year period, setting a production record for Maserati Spyders.

The first Spyder was launched at the Turin Motor Show in 1984. It was offered both with the two litre and two-and-a-half litre "export" engine. Two years later fuel injection arrived on the Spyder i. 297 were made in 2.0 L and 122 in 2.5 L form.

In 1989 the Spyder was facelifted as model year 1990, known as Spyder i 1990 (or '90). The car received the full 1988 Gandini treatment, one year after the other models: rounded grille, fuller bumpers, aerodynamic wing mirrors and 15" wheels on five-lug hubs. As on the rest of the Biturbos the export engine grew to displace 2.8 L. A four-speed automatic transmission was available on request.

The third series, or Spyder III, was introduced in 1991 in occasion of Gandini's second facelift that renewed the entire range. This included the new bonnet and grille, ellypsoidal headlights in body-colour housings, a spoiler at the base of the windscreen, deeper body-colour sills and 16" seven-spoke wheels. Spyder IIIs were fitted with Maserati's Ranger limited slip differential Whereas the 2.0 L third series Spyder received 24-valve engines, 2.8 L cars still used 18-valves, thus remaineing the only 2.8 L Biturbo model to never get a 4-valve head upgrade.

Maserati 228

The Maserati 228 (Tipo AM334) was a two-door, 5-seater GT coupé based on the Biturbo chassis. It was conceived to fill the void left in the Maserati range by the departed Kyalami, and was therefore aimed at the same market of the large GTs of the past like the 3500 GT and Mexico. To accomplish this it was based on the longer wheelbase chassis (2.6 m) of the four-door Biturbos, and powered by the largest, 2.8 litre, 18-valve fuel injected V6 (hence the name 228 – 2-door, 2.8 L engine). Bilstein gas shock absorbers replaced the usual hydraulic ones, and a 4-speed automatic transmission was available on order. The notchback coupé bodywork was styled by Pierangelo Andreani, and the car was wider and longer than the two-door Biturbos, with no common body panels; the interior was also more luxuriously appointed. Maserati declared the European-specification 228 could accelerate to 0–100 km/h (0–62 mph) in 5.6 seconds and reach a top speed of 235 km/h (146 mph). A 24-valve but still carbureted prototype was shown in December 1984; the production 228 was introduced at the 1986 Turin Motor Show, and 469 examples were made until 1992.

Maserati Karif

The Maserati Karif was an hardtop, 2-seat berlinetta based on the short Spyder chassis. It was fitted with the most powerful 2.8 L V6. Pairing the agile short wheelbase with a stiffer, enclosed body, it was the fastest and most exclusive coupé in Maserati lineup at the time.