Isuzu Impulse
From Wikipedia, the free encyclopedia
| Isuzu Impulse | |
| Also called: | Holden Piazza Isuzu Piazza Isuzu Piazza Nero Asüna Sunfire |
|---|---|
| Manufacturer: | Isuzu |
| Production: | 1981–1992 |
| Class: | Sport compact |
| Body style: | 3-door hatchback 2-door station wagon |
| Related: | Geo Storm Isuzu Gemini Isuzu Stylus |
The Isuzu Impulse was a small sporty 3-door hatchback (though always classified as a coupé by Isuzu) sold from 1981 through to 1992. The first generation Impulse was a rear-wheel drive car, but the second generation was front-wheel drive and all-wheel drive. The second-generation Impulse was based on the General Motors (GM)-influenced Gemini Coupe or Geo Storm as it was known in the US market, and the engine of the second-generation Impulse is the descendant of the Isuzu engine used in the modern Lotus Elan. The Impulse was also known as the Isuzu Piazza outside of the US, including in the UK where it was the first widely available Isuzu. In Australia it was badged the Holden Piazza, and sold by GM's Australian wing Holden.
Contents |
[edit] 1981–1989
In 1978, Isuzu commissioned Giorgetto Giugiaro to design a new sporty car to replace the 117 Coupe (also a Giugiaro design). They delivered several T Series Geminis to the Italdesign studio in Italy and allowed Giugiaro free reign of the design. The result of this effort was the wedge-shaped three-door hatchback called the Asso di Fiori ("Ace of Clubs") prototype and show car, that was shown at the 1979 Tokyo Motor Show to rave reviews. Giugiaro referred to the design as his fifth "Copernican revolution", integrating the design innovations of many different previous designs into one, mass producable, vehicle. Within 48 hours of its unveiling at the Tokyo Motor Show, Isuzu fast tracked the vehicle into production with minimal changes to the design.
In late 1981, the first Isuzu Piazzas went on sale in Japan, available with either 120-hp, 120 ft·lbf 2.0 L SOHC I4 engine or a 135-hp, 123 ft·lbf 2.0 L DOHC I4 engine. 5-speed manual and 4-speed automatic transmissions were available, and all models were rear-wheel drive. For the 1985 model year, a 180-hp, 185 ft·lbf turbocharged SOHC I4 engine was introduced, and the DOHC naturally aspirated engine was phased out in years that followed. Piazzas were available in a multitude of trim levels including Bella, XN, XJ, XE, XG, Nero, and others. There were three different suspension tuning levels, standard, Irmscher, and Lotus.
For the US market, this vehicle was introduced as the Impulse in 1983. For the 1983 and 1984 model years, only one engine was available, the 2.0 L SOHC I4 engine, rated at 90 hp, 108 ft·lbf. A turbocharged model was introduced in 1985, with a 2.0 L SOHC I4 engine rated at 140 hp and 166 ft·lbf. The 1988 model year saw several changes. Mild exterior and interior changes were made to the appearance of the vehicle (a larger rear spoiler, fixed headlights without pop up covers, etc.). The 2.0 L non-turbo engine was replaced with a 2.3 L SOHC I4 engine, rated at 110 hp, 127 ft·lbf (this engine was offered only in the US market). All Impulses received a Lotus-tuned suspension beginning in the 1988 model year, which consisted of redesigned sway bars, stiffer dampers, and a change in previous spring rates.
In the US market, the Impulse was marketed as "everything standard", meaning that all Impulses came with all available equipment for the vehicles model year, and only two trim levels offered: non-turbo and Turbo. There were, however, some special edition models, most notably the RS model of the 1987 model year, available only in white body color with pewter color trim, and featuring the stiffest suspension available on any Impulse, very close to the Irmscher suspension sold only in Japan. For the 1989 model year, a "Special Edition" non-turbo model was offered, which was equipped with the Turbo model wheels and interior trim.
The vehicle was sold as the Piazza in Europe and Australia, though introduced into these markets in 1985 or later. In the UK the Piazza was sold in most of the trim levels offered in Japan, in both Turbo and Non-turbo forms. In Australia, the Piazza was introduced very late (April 1986), and offered only in Turbo form.
Performance of the Turbo model was comparable to the Mitsubishi Starion or Dodge Conquest, as demonstrated by the fact that the acceleration and handling numbers reported by the auto enthusiast magazines were within 0.1–0.2 seconds between the vehicles.
In the US, the Impulse was replaced by the second generation Impulse after the end of the 1989 model year. However, in Japan, the first generation Piazza continued production and was available through the 1991 model year.
[edit] 1990–1992 (1990–1993 in Canada)
The second generation Impulse was designed on General Motors's second generation R-body "world car" platform. GM had commissioned Isuzu to build a replacement for the Spectrum, this time a more sporty model to be called the Storm (Gemini Coupe in Japan). The body design of the Storm was strongly influenced by GM and drew heavily from GM Europe's design submission for the Elan M100. Under Shiro Nakamura, Isuzu's then head of design, the third generation Gemini sedan was first designed on this platform, and then attention was turned to a sporty coupe to replace the first generation Impulse. Starting with the Storm, alternative front and rear treatments were made, retaining the lozenge theme of the Gemini sedan, and drawing heavy influence from the rear-wheel drive Impulse (semi-concealed headlights with integrated grille as well as hood and taillight styling) while also expanding on the "European look", which later became a central point of marketing the vehicle in Japan.
The three-door hatchback debuted as the Impulse XS in 1989 for the 1990 model year. It was offered only in front-wheel drive with a DOHC 1.6 L (1588 cc) I4 engine which produced 130 hp (97 kW). The suspension consisted of MacPherson struts both front and rear, with a rigid trailing arm front suspension and a multi-link rear suspension, featuring Nishiboric passive steering.
For the 1991 model year, the Impulse RS was introduced with a 160 hp (119 kW) turbocharged engine and all-wheel drive drivetrain which featured front and rear viscous differentials and center helical differential. The wagonback model was also introduced for the 1991 model year, only available with the normally-aspirated 1.6 L engine.
For the 1992 model year, the Turbo model was discontinued and the base engine was replaced with a 1.8 L (1794 cc) engine, sharing the same bore but with a longer stroke due to the taller engine block. This larger powerplant was good for 140 hp (104 kW) and 125 ft·lbf (169 N•m). . Both body styles continued into 1992, but very few were produced.
Since the Impulse weighed just 2411 lb (1094 kg) in front-wheel drive configuration and 2732 lb (1239 kg) in all-wheel drive configuration, the turbo engine and all wheel drive combined gave excellent performance.
General Motors, who owned nearly half of Isuzu, also owned Lotus Cars at the time. Lotus selected the 1.6 L engine and transmission from the Isuzu Gemini for the Lotus Elan and a following generation of that engine eventually ended up in the Impulse. Lotus was subcontracted by Isuzu to fine tune the suspension of the Impulse, through selection of stiffer dampers, larger sway bars, and softer springs. All of the second generation Impulses had the Lotus-tuned suspension.
A non-Lotus innovation in the Impulse was the development of the Nishiboric passive rear-wheel steering system which adjusted the toe of the rear wheels by changing the rear wheel alignment through the range of suspension travel.
The combination of the burst of the Japanese economic bubble, rising emissions and crash safety requirements, and continued restrictive market segment meddling by General Motors forced Isuzu out of the car making market and brought an end to the Impulse.
In the Japanese market, this vehicle was sold as the Piazza beginning in July 1991 through to spring of 1992. The second generation Piazza was offered only in front-wheel drive with the 1.8 L engine. All of the second generation Piazzas came with the Lotus-tuned suspension.
In the Canadian market, the same models, with minor variations, were sold in the 1990 & 1991 model years. No Impulses were made for Canada for the 1992 model year. In 1993 the 1.8 L model was sold in Canada as the Asüna Sunfire, but only with the hatchback body.
[edit] References
- ↑ Giugiaro Italdesign Catalogue Raisonne 1959–1987. Bruno Alfieri, Editor. 1987. Automobilia International Publishing Group. Milano, Italy. Vol. 2; P. 108–109.
- ↑ Giugiaro Italdesign Catalogue Raisonne 1959–1987. Bruno Alfieri, Editor. 1987. Automobilia International Publishing Group. Milano, Italy. Vol. 2; P. 191–194.
- ↑ Giugiaro Italdesign Catalogue Raisonne 1959–1987. Bruno Alfieri, Editor. 1987. Automobilia International Publishing Group. Milano, Italy. Vol. 2; P. 216.
- ↑ "Isuzu Piazza". Car Styling Quarterly. Vol. 35. July 1981.
- ↑ Isuzu Piazza, 117 Coupe, and Bellett GT. 1998. Neko Publishing Co. Ltd. Tokyo, Japan. ISBN 4-87366-026-2.
- ↑ 45 Years of Holden. By Terry Bebbington & Michel A. Malik. The Australian Publishing and Printing Co. Distributed by Classic Motorbooks. ISBN 0-947216-31-6.
- ↑ Lotus Since the 70's; Volume 1: Elite, Eclat, Excel, and Elan. By Graham Robinson. 1993. Motor Racing Publications Ltd. Croydon, England. ISBN 0-947981-70-5.
- ↑ Osprey Automotive Lotus Elan. By Mark Hughes. 1992. Osprey Publishing. London, England. ISBN 1-85532-194-7.
- ↑ Car Men 45; Shiro Nakamura, Nissan Design. By Marzia Gandini. Bruno Alfieri, Editor. 2003. Automobilia s.r.l. Italy. ISBN 88-7960-152-0.
