The GM and Hydra-Matic made TH400 is an automatic transmission. Also erred to as the "Turbo 400," the TH400 is considered very durable and of high quality, according to the auto experts at Novak-Adapt.com.
History
The TH400 started out in 1964 when it was used in Buicks and Cadillacs. After a few years in cars, GM began putting the Turbo 400 in trucks in the 1970s. In 1990 GM changed the name to the 3L80, though the transmission is still being used in GMs heavy-duty vehicles and in military applications.
Specifications
The TH400 weighs 135 lbs and is 24.37 inches long. Encased in smooth cast aluminum casing, the Turbo 400 is GMs largest automatic transmission and features a 3.48, 1.48 and one gearing.
Variations
GM created two alternate variations of the TH400. The TH475 was used in GMs most heavy-duty trucks starting in 1971. The TH375, used between 1972 and 1976, was used in cars with small displacement.
Potential
According to Novak-Adapt, the Turbo 400 is a popular transmission often used in Jeep conversions. Theyve also been used in GM vehicles, Rolls-Royces, Jaguars and even Ferrari models.
The turbocharger is an exhaust-driven supercharger. It has been used to increase power in combustion-type engines for cars, trucks and marine vessels. The turbocharger, or "turbo" for short, is one of the most cost-effective ways to raise power and combustion efficiency. In recent history, the turbo has grown to be a favorite aftermarket addition for car enthusiasts.
History
In 1925, Alfred Bchi was the first to develop an effective and functional exhaust gas turbocharger; he was able to achieve a power increase of around 40 percent. The turbos to follow in his design would mostly be used in large engine applications such as those found in marine vessels. 1938 marked the year of the first turbocharged truck, and it would take nearly half a century more for the turbo to really catch on with the automotive industry. In the 1970s, the turbo started to find its way into commercial diesel engines, race applications and aftermarket additions for cars.
How It Works
A turbocharger has two main parts: the compressor housing and the exhaust housing. These two housings contain small fans connected by a shaft. The exhaust fan housing is connected to the exhaust manifold; as exhaust gas passes through the housing, it spins the fan. The exhaust fan, in turn, drives the compressor fan attached to the intake side of the engine. The compressor fan does exactly that; it compresses the intake air into the engine cylinders for a greater combustion, creating to more power.
Orientations
Turbo kits come in a couple different orientations: single turbo, sequential twin turbo and twin turbo. The single turbo is the most common because it is easily fabricated to fit most applications. On larger engines with six cylinders or more, some opt for a sequential twin turbo setup. This orientation will usually be set up to run in two different stages using only one turbo at a time. V-type engines will sometimes utilize a turbo for each cylinder bank; this is similar to the sequential twin turbo setup, but these turbos will spin simultaneously.
Size
"Bigger is better" is not always a true statement. Small gasoline engines do not emit large enough amounts of exhaust gas to turn large turbochargers; smaller turbo units can be used to achieve higher power. This can even be true for larger gasoline engines, which is why the twin-turbo setup was introduced, as it is easier for an engine to drive two small turbochargers than one large one. Diesel engines are the exception to the rule and can drive almost any size turbo fan.
Benefits
When you are using a turbo application, you can adjust the amount of boost the turbo will generate. Boost is the pressure at which air is compressed into the combustion chambers; when you run higher boost, you achiever higher amounts of power at the turn of a dial. Running high boost can be hazardous to your engine, but if you find a safe boost level, your engine will be running at top efficiency.
Warnings
Overboost is when a turbo is allowed to compress too much air into the combustion chamber and can damage the engine. It is easy to overboost an engine to a dangerous level. It is important to seek guidance when making these adjustments and making any further engine modifications necessary.
