Maserati Bora

Maserati Bora
Overview
Manufacturer	Maserati
Production	1971–78 (Bora 4.7 L) 289 produced[1] 1973–78 (Bora 4.9 L) 275 produced[2]
Designer	Giorgetto Giugiaro at Italdesign
Body and chassis
Class	Sports car
Body style	2-door coupe
Layout	RMR layout
Related	Maserati Merak
Powertrain
Engine	4.7 L (4,719 cc) V8 4.9 L (4,930 cc) V8
Transmission	5-speed ZF manual
Dimensions
Wheelbase	2,600 mm (102.4 in)
Length	4,335 mm (170.7 in)
Width	1,768 mm (69.6 in)
Height	1,134 mm (44.6 in)
Curb weight	1,830 kg (4,034 lb)
Chronology
Predecessor	Maserati Ghibli
Successor	Maserati MC12

The Maserati Bora (Tipo 117) is a mid-engined two-seat coupe manufactured by Maserati from 1971 to 1978. It is powered by a V8 engine and has a top speed of 171 mph (275 km/h).

History

Shortly after Citroën took a controlling interest in Maserati in 1968, the concept of a mid-engined two-seat sports car was proposed. Lamborghini and De Tomaso already had the Miura and Mangusta, whilst Ferrari were known to be developing their own mid-engined contender. Initially known as Tipo 117 and later the Bora, the Maserati project got underway in October 1968 and a prototype was on the road by mid-1969. Shown in its final form at the Geneva Salon in March 1971, deliveries began before the end of the year. Maserati struggled after being bought by De Tomaso in 1975, and the Bora was discontinued after the 1978 model year. 564 Boras were produced in total, of which 275 were fitted with 4.9 L engines and the other 289 were fitted with 4.7 L engines.^[3]

Design

The Bora was designed by Giorgetto Giugiaro at Italdesign and has a drag coefficient of 0.30.^[4] Fabrication of the all-steel panels was contracted to Officine Padane of Modena. The Bora had a number of innovative features that distinguished the car from Maserati's previous offerings. Compared to other supercars, it was civilized and practical, featuring a hydraulically powered pedal cluster that could be moved forward and backwards at the touch of a button and a steering wheel that could be tilted and telescoped, addressing the familiar problem of entering and exiting the vehicle typical of many supercars.

Most supercars offer little foot room and little to no provision for luggage, but the Bora has a full-size trunk in the front of the vehicle, and was otherwise known as being much more civilized in comforts from its competitors. Unlike its competitors, the Bora used dual-pane glass separating its cabin from the engine compartment as well as a carpeted aluminum engine cap, greatly decreasing the engine noise in the cabin and increasing the comfort level for the driver. The engine and five-speed ZF transaxle were mounted on a subframe attached to the monocoque via four flexible mounts, which also helped the ride quality.

1972 Maserati Bora 4.7 litre Coupé at Paris - Bonhams in 2014

Specifications

Rear view

Two V8 engines were offered initially, a high-revving 4,719 cc (4.7 L; 288.0 cu in) and a higher torque 4,930 cc (4.9 L; 300.8 cu in); a US smog-qualified 4.9-litre engine was used (a stroked version of the 4.7), starting with 1973 deliveries. The 4.7 L V8 produces 310 hp (230 kW; 310 PS) at 6,000 rpm and 325 lb⋅ft (441 N⋅m) of torque at 4,200 rpm. Eventually, production switched to only using a more powerful version of the 4.9-litre engine producing 320 hp (324 PS; 239 kW) at 5,500 rpm and 454 N⋅m (335 lb⋅ft) of torque at 4,000 rpm.^[5] All these engines traced their lineage back to the famous 450S racecar, were aluminium alloy, had hemispherical combustion chambers with 16 valves total operated by four cams (chain-driven). Both engines were mounted longitudinally in the middle of the car and were mated to a ZF-1 five-speed transaxle sending power to the rear wheels. They were fed by four 42 DCNF/14 downdraught Weber carburetors with Bosch electronic ignition. The compression ratio is 8.5:1.

A combined steel monocoque chassis and body featured a tubular steel subframe at the back for the engine and transmission. Also featured independent suspension all round (a first for a Maserati road car) with coil springs, telescopic suspension dampers and anti-roll bars.^[6] The development prototype and the broadly similar show car first seen at the 1971 Geneva Motor Show featured MacPherson strut based front suspension, but this was abandoned for production because, installed in combination with very wide front tires and rack-and-pinion steering, the strut-based solution produced severe kickback. For the production cars Maserati reverted to a more conservative wishbone front-suspension arrangement.

Citroën's advanced high-pressure LHM hydraulics were adopted to operate the ventilated disc brakes on the main circuit, and on an auxiliary circuit the pedal box [clutch, brake, foot-throttle], the driver's seat [only vertical adjustments], and the retractable headlights.^[4] Wheels were 7.5 in × 15 in (190.5 mm × 381.0 mm) Campagnolo light alloy rims with distinctive removable polished stainless steel hubcaps in the earlier automobiles. Tyres were Michelin XWX 205x70 front and rear, however these early cars exhibited problems with "tramlining" at speed. To solve this problem Maserati fitted later cars with 215x70 Michelins.

Standing 1,138 mm (44.8 in) high, perhaps the most distinctive details were the brushed stainless steel roof and windscreen pillars. Inside, the bucket seats, dash, door trim, centre console and rear bulkhead were trimmed in leather, with electric windows and air conditioning as standard. The steering column was manually adjustable for rake and reach, whereas the LHM aux. circuit controls adjusted the driver's seat vertically, the pedal box [consisting of the brake, clutch and throttle pedals] horizontally forwards and backwards by around 76 mm (3.0 in)--a first such application in the world for a production car, and also to raise and lower the concealed headlights in the front fenders.

The original design weight was 1,400 kg (3,100 lb), however, noise and safety concerns pushed this up to 1,535 kg (3,384 lb). It is popularly believed that the Bora is heavier than the Ghibli however the Ghibli weighs some 1,650 kg (3,640 lb), 115 kg (254 lb) more than the Bora. The reason for this misconception probably stems from the state of tune of their respective engines as well as the difference in the gearing of the two cars. The Ghiblis' 4.7 litre motor was tuned to give 335 PS (330 bhp; 246 kW) in SS form, whilst the 310 PS (306 bhp; 228 kW) Bora was tuned for a smoother power delivery but more initial ignition advance gave it more power lower in the rev range. Differences in the gearing are a little harder to understand, the Ghibli had the option of two final drives 3.31 or 3.54 both of these lower than the Boras' 4.11 in US form or 3.77 for the few RHD cars, also having a 2.97 first gear verses 2.86 in the Bora made the heavier but more powerful Ghibli accelerate at almost exactly the same rate as the Bora, initially. However as speed climbed the more highly geared Bora (5th gear of .74 verses .90 in the Ghibli) would take the lead, top speeds were similar at 154 to 160 for the Ghibli verses 155 mph (249 km/h) for US spec Boras' and up to 174 mph (280 km/h) for RHD and European spec cars without smog controls. This has led to confusion over this issue as well as the top speeds of US spec verses European geared cars. The first Boras were delivered to customers in late 1971, and only minor production changes were gradually phased in thereafter. About early 1974, front lids became hinged at front instead of rear, pop-up headlights showed rounded inside corners, and a rectangular black air-exit grille was added across the hood (similar to Pantera). From 1973, as the 4.7-litre engine had not been homologated in North America, US Bora models had air-pump emissions-equipped 4,930 cc (4.9 L; 300.8 cu in) Super-Ghibli engines similar to those found in US-bound Ghiblis. Output was 310 PS (306 bhp; 228 kW) at 6,000 rpm, 30 bhp (22 kW) or less than the Euro-spec' derivative.

US-spec 1974 Maserati Bora

US safety-compliant front bumpers had to be added to meet US DOT safety legislation, on US-delivered cars, though many US Bora owners have subsequently retro-fitted the original Euro versions. Three years later, the 4.9-litre engine became standard on all Boras, displacement having been stroked from 85 to 89 mm, resulting in a size of 4,930 cc. With compression set at 8.75:1, output was 10 bhp (7.5 kW) up on the 4.7 with 320 bhp (240 kW) (330 bhp (250 kW) in Europe) at 5,500 rpm. Production ran from 1971 to 1978, with 564 Boras built, 289 of which were 4.7s and the remaining 275, 4.9s. As time has passed, many US states including California have allowed smog exceptions for older cars, and it is not uncommon for US 4.9 Bora owners to have "adjusted" matters for optimum supercar-spirited performance.

Maserati created two Group 4 racing Boras at the request of Thepenier, a French Maserati dealer. They were very competitive, but Maserati couldn't produce enough cars to meet the 500 road car homologation rule for Group 4 racing so the project was shelved.^[7]

The Bora was the basis for the Merak, which used the same bodyshell front clip but in a 2+2 configuration, made possible by using a smaller, lighter and less powerful Maserati V6 engine, also used in the Citroën SM. The Merak was popular, and sold thousands in number, including the later modified and improved Merak SS, making its 1981. Merak models had an opened rear engine-cover instead of the glass-enclosed and heavier rear of the Bora.

References

Citations

Further reading

• Lamm, John (2006). Velocity – Supercar Revolution. MBI Publishing Company. ISBN 978-0-7603-2596-4.

External links

Wikimedia Commons has media related to Maserati Bora.

• Bora