1978 Dodge Challenger

The late 1970s and early 1980s were a difficult time for muscle car enthusiasts in the United States. The emissions regulations were always getting more strict, and when combined with the new federal regulations on engine testing, showed in the form of a gradual drop in horsepower in models such as the Corvette, the Camaro, and the Mustang. These strict regulations were what caused the decline in muscle car sales in the mid 1970s, thus causing the end of production for many legendary performance cars. The Corvette retained a V8 engine, but with a steep decline in advertised horsepower. The Camaro and Mustang, on the other hand, while still offering relatively low performance V8s, also offered very low performance 4 cylinder engines. This was also around the time where many popular Japanese automakers were making their formal introduction into the US market. One of those companies was Mitsubishi, and while they would not have their official entry into the US market until 1982, a 1971 purchase of a large part of the Mitsubishi Corporation helped pave the way for a Mitsubishi built car in the US, in the form of the 1978 Plymouth Sapporo and Dodge Challenger.

When Honda Motor Company entered the US market, there were alot of people who were very pro-American, or moreso anti-Japan, and this attitude caused lower than expected sales when the Japanese models were released. However, the partnership created between Dodge and Mitsubishi allowed Mitsubishi to to enter the market under an "American" name, with the added recognition of the popular "Challenger" name plate. This rebirth of a great pony car name got the attention of enthusiasts, and Mopar enthusiasts looked forward to the launch of the new Challenger, but this new model was no longer a high performance pony car, but more of a compact luxury model. Also, while having a storied American name, it had a distinctly Japanese look and feel. The Challenger(and Plymouth Sapporo) were only released under that name here in the US and in Puerto Rico, but the car was offered pretty much world wide. In Europe and South America this car was marketed as the Mitsubishi Galant Sapporo; in Australia it was badged as the Chrysler Scorpion and that was later changed to the Mitsubishi Scorpion; and in Japan, the model was badged as the Mitsubishi Galant Lambda.

While the new Challenger focused more on economy and luxury than performance than on performance, the engines offered in the Challenger were peppy considering they were only 4 cylinder engines. The two engines offered were a 1.6L, and a 2.6L. The 1.6L was a Mitsubishi 4G32, and this was the economy engine, and was far less preferred by someone. This was an 8-valve SOHC design with a five main bearing iron block, topped with an aluminum cross flow head, and single barrel carburetor. The "performance engine" was an unusually large 4 cylinder, and had a technological advance which allowed this engine to have such high displacement. This new 2.6L engine was the Mitsubishi 4G54, and it was a longitudinally mounted engine for use in rear wheel drive and all wheel drive vehicles. Much like the fabled Challengers of the muscle car era, the 2.6L had an aluminum hemispherical head with chain driven single overhead camshaft atop a five main bearing iron block, all topped off with a Hitachi 2 barrel carburetor with vacuum operated progressive secondary.

The unique addition of this engine, allowing it to have such a large displacement, was the "Silent Shaft" feature, which assisted in counter-balancing the motion of the engine to make the engine much more smooth at all rpm ranges. Also, the US market models featured a small, third valve in the cylinder heads called the "Jet Valve", which helped to allow for leaner fuel-to-air mixtures for lower emissions. When this 3-valve system was being designed, the cost of a redesigned head would have greatly outweighed the advantages, so instead, slight alterations were made to the existing head. Inside the cam cover, a threaded hole (similar to the spark plug hole) was inserted, and a cartridge containing the valve spring and seat were screwed into this hole, and the valve springs used were very soft so they would not cause any increased wear on the camshaft. The other slight alteration to the engine was the positioning of the rocker arms on the intake valves, which were widened on the valve end to allow room for the extra valve. This engine received great reviews for both the low level of emissions without a great power loss, as well the smoothness obtained by the addition of the balance shafts. Unfortunately, the engine also has some megative reviews, the most common being the warping and/or cracking of the cylinder heads due to heat, and repairing this problem was very expensive since the parts had to be shipped from Japan, and rebuilt heads were hard to come by during this time. Another problem with the Challengers, like many carbureted cars of this era, drivability often suffered with the stock carburetor, so an upgrade kit which included, among other things, larger carb jets which richened the air-to-fuel mixture. Another problem with the Hitachi 2 barrel carburetor with vacuum operated progressive secondary was the failure of the vacuum diaphragms, and like the cylinder head issues, this problem was expensive to fix. Many peoples who encountered this problem bought a Weber conversion kit, which cured the issue, as well as served as a performance upgrade.

While some overseas models received such items as a turbocharged gasoline or diesel engine and rear independent suspension, the Challenger offered only the aforementioned 1.6L and 2.6L naturally aspirated engines, and a solid rear axle. However, the close ratio manual transmission was standard, with a three speed automatic optional, as well as the aluminum alloy wheels and read disc brakes, but these two options only came together, and could not be ordered separately. In order to emphasize the 'luxury' aspect of the new Challenger, the plush velour seats could be replaced with leather; and air conditioning, a cassette player, cruise control, power door locks, power windows, and a moon roof could be chosen at an additional cost. Whether the optional cassette player was chosen or not, a Mitsubishi made high quality stereo system was standard, with a built in invisible antenna, which was built into the trunk lid. Also, the car was packed full of "courtesy lights", and in the fuse box, the operator would find a built in fuse test light. In later years a convertible top was offered in addition to the hardtop, giving the Challenger another attractive option.