Saturday, August 13, 2011

Mazda MX-5 Miata Roadster, 1989

 

Mazda MX-5 Miata Roadster, 1989

The Mazda MX-5 is a popular sports car built by Mazda in Hiroshima, Japan, since 1989. It is known as MX-5 Miata (or popularly just Miata) in North America, MX-5 in Oceania and Europe, and Roadster (under the Eunos marque until 1996) in Japan. The MX-5 is one of the world's best-selling sports cars, with 748,904 cars sold until the end of 2005. Beginning with the third-generation 2006 model, Mazda consolidated worldwide (excluding Japan) marketing using the MX-5 name, though enthusiasts in the USA (and the company itself) still refer to it as Miata, a name that means "reward" in Old High German.

The return of the sports roadster
The MX-5 was envisioned by its designers as a small roadster with a minimum of unnecessary weight and complexity, a direct descendant of the small British roadsters of the 1960s such as the Triumph Spitfire, MG Midget, Lotus Elan, and Porsche 550 Spider. By the early 1980s, roadsters had all but vanished from the market, sacrificed to the increasing safety and anti-pollution regulations everywhere. The MX-5 would thus mark the return of the roadster, using modern technology allied to the tradition of the roadster type.

As a result, the MX-5 has a traditional FR (front-engine, rear-wheel-drive) layout and 4-wheel independent double wishbone suspension. It comes with a longitudinally mounted four cylinder engine coupled to a manual transmission (an automatic transmission is available as an option).
The body is a conventional, but very light, unibody shell. The MX-5 also incorporates a unique trusswork called the Powerplant Frame (PPF) which connects the engine to the differential, minimizing flex and creating a tight, responsive feel. Many MX-5s feature limited slip differentials and antilock brakes. Traction control is an option available on some models.

With an approximate 50:50 front/rear weight balance, the car has very neutral handling, which makes it easy to drive for the beginner, and fun for the advanced driver. Inducing oversteer is easy and very controllable. The MX-5 is thus popular in amateur and stock racing events, including, in the USA, the Sports Car Club of America's Solo2 autocross and Spec Miata race series.

As a measure for success, the Guinness Book of Records declared the MX-5 Miata the world's best-selling sports car on February 13, 2002, with more than 700,000 sold until that date.
The MX-5 has won over 150 awards in its history, including making Car and Driver magazine's annual Ten Best list seven times; Wheels Magazine 's Car of the Year for 1989 and 2005; Sports Car International's "best sports car of the 1990s" and "ten best sports cars of all time"; 2005-2006 Car of the Year Japan; and 2005 Australian Car of the Year.

There have been three generations of the MX-5, each introducing overall changes to the exterior, interior and mechanical components of the car: the first generation, with production code NA, was produced from 1990 to 1997 in model years; the second generation, NB, from 1999 to 2005; and the current third generation, NC, from 2006.

The competition to design the MX-5
The design of the first MX-5 was the result of an internal Mazda competition between the two Design Studios in California, USA and Tokyo, Japan. The role of designing an FR (front-engine, rear-wheel drive) light-weight sports car was assigned to the California Design Studio whilst at Tokyo two different models were entered the competition: an FF layout (front-engined, front-wheel drive) and an MR layout (mid-engined, rear-wheel drive).

The first round of judging the competing designs for the MX-5 was held in April 1984. Designs were presented on paper. The mid-engined car appeared the most impressive, although it was known at the time that such a layout would struggle to meet the noise, vibration and harshness (NVH) requirements of the project. It was only at the second round of the competition in August 1984, when full-scale clay models were presented, that the California FR design, codenamed "Duo 101", won the competition and was selected as the basis for Mazda's new light-weight sports car.

The Duo 101 design, so named as either a soft-top or hard-top could be used, incorporated many key stylistic cues inspired by the Lotus Elan, a 1960s roadster widely considered as one of the best-handling sports cars of its day. International Automotive Design (IAD) in Worthing, England was commissioned to develop a running prototype. It was built with a fiberglass body, a 1.4-liter engine from a Mazda Familia and components from a variety of early Mazda models. The prototype was completed in August 1985.

After some minor changes in the design, the project received final approval on January 18, 1986 and the car was now codenamed P729. The task of constructing five engineering mules (more developed prototypes) was again allocated to IAD, which also conducted the first front and rear crash tests on the P729. The project was moved to Japan for final engineering details and production issues to be decided. The MX-5 was almost ready to be introduced to the world as a a true light-weight sports car, weighing just 940 kg (2070 lb).

First Generation (NA)

The MX-5 was unveiled at the Chicago Auto Show on February 10, 1989, with a price tag of US $13,800 (US $22,650 in 2006 adjusted for inflation). The MX-5, with production code NA, would be available for delivery to buyers on July 1989 as a 1990 model. An optional hardtop was made available at the same time, in reinforced engineering plastic.

In Japan, the car was not badged as a Mazda, as the company was experimenting with the creation of different marques for deluxe models, similar to Nissan's Infiniti and Toyota's Lexus. Instead, the Mazda MX-5 was sold as the Eunos Roadster in that market.

The body shell of the NA was all-steel with a light-weight aluminium hood. Overall dimensions were 3970 mm (156.3 in) in length, 1675 mm (65.9 in) in width, and 1235 mm (48.6 in) in height. Drag coefficient was indicated as 0.38, reasonably aerodynamic. Suspension was an independent double wishbone on all four wheels, with an anti-roll bar at the front. Four wheel-disc brakes, ventilated at the front, were behind alloy wheels with 185/60HR14 radial tires.

The original MX-5 came with a 1.6-liter double overhead cam inline four-cylinder engine, producing 90 kW (120 hp) and 100 ft·lbf (136 N·m) of torque. The engine employs an L-Jetronic fuel injection system and a camshaft angle sensor instead of a distributor. This engine, codename B6, had been previously used in the 323 series, including the 323 GTX, a turbocharged, all-wheel drive vehicle, and retained the reinforcements and under-piston oil sprays required for aftermarket turbocharging.

Standard transmission was 5-speed manual. Japan and the USA got an optional automatic transmission which proved unpopular; these markets also received an optional viscous limited slip rear differential.

The NA could reach 96 km/h (60 mph) in 9.4 s and had a top speed of 190 km/h (119 mph).
For the 1994 model year, the first-generation MX-5 was freshened with the introduction of the more powerful 1.8-liter BP engine, dual airbags and a geared, torque-sensing limited slip differential in some markets. The chassis was substantially braced to meet new side-impact standards, most obviously by adding a bar between the seatbelt towers inside the car, but also to the front and rear subframes. No exterior changes were made, though. This is called the NA Generation 1.5.

The new engine produced 98 kW (130 hp), increased to 133 hp (99 kW) from 1995. The base weight increased to 990 kg (2180 lb). Performance was improved slightly, the additional power being partly offset by the extra weight. In some markets such as Europe, the 1.6 engine continued to be available as a lower-cost option, but was detuned to 88 hp (66 kW). This lower-powered model did not receive all the additional chassis bracing of the new 1.8. Japanese and US cars were fitted with an optional Torsen LSD, which was far more durable than the previous viscous differential.

There were a number of trim levels and special editions available, determined by local Mazda marketing departments. In the US, the base model was called the "A Package". A "B Package" added some options, while the "C Package" included a tan interior and top and leather seats. The "R Package" was for racing, and the annual special editions were formalized as "M Editions" from Generation 1.5. These included all of the luxury options from the "C Package" as well as special paint and, sometimes, special wheels.

The first generation MX-5 was phased out with the 1997 model year (there was no 1998 model year), with the final 1500 NAs produced for the US market being the "STO" ("Special Touring Option") versions.

Second Generation (NB)
In 1998, Mazda released the second-generation MX-5, production code NB, for the 1999 model year. The NB featured a more powerful engine and, on the exterior, more modern styling cues borrowed from the 1992 Mazda RX-7 model. Prices in the United States, the main market for the MX-5, started at US $19,770 (US $24,680 in 2006).

Though many parts of the interior and body were different, the most notable changes were the headlights: the first generation's retractable headlights had been exchanged for fixed ones. The new car had grown slightly in width compared to the earlier model with dimensions: length 3955 mm (155.7 in); width 1680 mm (66.1 in); height 1235 mm (48.6 in) and wheelbase 2265 mm (89.2 in). Without options, the NB weighed exactly 1000 kg (2205 lb). The new generation was slightly more aerodynamic than the original, with a Cd figure of 0.36.

Fiat-15-25 HP Brevetti Tipo-2, 1908

 
Fiat-15-25 HP Brevetti Tipo-2, 1908



Porsche 911 Carrera, 1997

 
Porsche 911 Carrera, 1997

The Porsche 911 Carrera represented the "base model" of the 993, and was available in rear and all-wheel drive versions. It was equipped with the naturally aspirated 3.6 liter M64 engine, further developed from the 964 and combined with a new dual-flow exhaust system now incorporating two catalytic converters. In contrast to the Type 964, Porsche deleted the "2" from the rear-wheel drive "Carrera" name tag. However among enthusiasts, to differentiate between the rear-wheel and all-wheel drive variants of the Type 993 Carrera they were (and still are) commonly referred to as "C2" and "C4", respectively.

The options list for the Porsche 993 Carrera (and most other variants) was extensive and offered the possibility to easily configure highly individualized cars, depending on the amount of money a buyer was willing to spend. Options included up to five different styles of wheels, various suspension set-ups, at least three different seat styles (comfort, sport, racing), uncountable upholstery options including the possibility to have almost any interior element of the car covered with leather, wood or carbon fiber, and various hi-fi systems including digital sound processing. Further, Porsche offered the option to a customer to have their car painted in any color that they may desire if the standard palette wasn't satisfactory. Even more, the Tequipment- and Exclusive-Programs added further options and built to order almost any specific wishes of customers such as special consoles, fax-machines or even brightly colored interior upholstery.

The Cabriolet, introduced 1995, features a fully electrical and hand-stitched softtop reinforced with metal sheets and an automatic windblocker.

Both coupe and cabriolet versions were available with all-wheel drive under the tag 'Carrera 4'. From the outside the Porsche 911 Carrera 4 is distinguishable by clear front turn markers and rear red markers (each instead of orange). The brake calipers are painted silver as is the 'Carrera 4' badge on the hood. The center wheelcaps carry the Carrera 4 logo instead of the Porsche crest.

In contrast to most of the following other variants, production of the Porsche 911 Carrera Coupe and Cabriolet ceased with the end of model year 1997, except for a very few produced in a shortened 1998 model year.

Technical improvements
One of the changes in the 993 over preceding 911s is the implementation of an all-alloy multi-arm rear suspension attached to an all-alloy subframe. Its design was derived from the project 989, a four-door sedan which never went into production, and was later continued in the 993's successor, type 996. It required the aforementioned widening of the rear wheel arches, which itself helped the 993's stability. This suspension improved the 993's cornering abilities, making it more direct and more stable and helping to reduce the tendency to oversteer if throttle was lifted during hard cornering, a trait of earlier 911s. It also reduced interior noise and improved ride quality.

The 993 was the first generation of 911 to have a standard six-speed manual transmission; previous cars, except for the Porsche 959, had 4- or 5-speed gearboxes. In virtually every situation, it was possible to keep the engine in its best torque range above 4500 rpm. The Porsche 911 Carrera / Carrera S / Cabriolet and Targa models (2WD) were available with a "Tiptronic" 4-speed automatic transmission, first introduced in the 964. Beginning with model year 1995, Porsche offered the Tiptronic S with additional steering wheel mounted controls and refined software for smoother, quicker shifts. Since the 993's introduction, the Tiptronic is capable of recognizing climbs and descents.

Further, the 993's optional all wheel drive system was refined over that of the 964. Porsche departed from the 964's setup consisting of three differentials and revised the system based on the layout from its 959 supercar, replacing the centre differential with a viscous coupling unit. In conjunction with the 993's redesigned and recalibrated suspension, this system improved handling characteristics and still retained the stability offered by AWD without having to suffer compromises in understeer. Its simpler layout also reduced the system's weight.

Other improvements include a new dual-flow exhaust, larger brakes with drilled discs, and revised power steering.

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