The past turbocharger, It only provides more power to the engine.There are some problem caused; Turbo Rag (insufficiency of low-cycle torque) and the knocking sounds.Recently, the fuel injection and VGS(Variable Geometry System) technology develop and these system help to change the turbocharger's function.It solve the turbo rug problem and give more power to low-cycle torque.Trucks and buses turbocharger can use these system, too.The turbocharger helps for down-sizing engine.
Power Curve for Truck turbocharger with VG
VG(Variable Geometry)About Turbochargers
Depends on engine load and rotations for Diesel engine, VG turbocharger has changed vane open/close control with variable nozzle.It also controls flow of the air and changing the rotation for the rotor.Engine can get right amount of air and also get high conbustion efficiency.We can keep both middle-low speed of torque and high output and also keep the exhaust gas clean.
Low torque at Low Revs: Opening space is smaller to keep efficiency of air supply.
High torque at High Revs: Opning space is bigger and keep the roter cycle lower.
For all torque and Revs, it supplys appropriate air and get high conbusion efficiency. It is possible to increase amount of air supply with low torque.(Please refer the chart above)
The structure is complecated and the cost is higher.
For the nozzle, the warn will occur because of no lubrication and high temperature. (Truck Makers recomended to exchange with 500 thousand to 800 thousand kilometers)
Changing the status of exhaust gas regulation for Trucks/Bus
In the market of Truck and Bus, there are downsizing engines which follows the regulation of the exaust gas.
From 2007, about 200,000 unit of all trucks over 2tons have turbocharger.Euro 3 has began from 2004, system of circulatory system has changed open system to closed system. It also sorounded devices have equipped and evoluted.
Popular small vehicle with VG turbocharger
It depends on the year and vehicles of the turbocharger for engine model 4JJ1, it connects in series with 2 different turbochargers; high-pressure stage and low-pressure stage. It called two stage turbocharger which is possible to control the air supply with wide-range torque and high efficiency of combution. Major vehicle with the turbocharger is Elf(Isuzu), Condor(UD), and Titan(Mazda).
The turbocharger for engine model 4P10, The registration for new vehicle is increasing and new model. The demand in the market will be increase in near future. Major vehicle with the turbocharger is Canter(FUSO) and Kazet(UD).
This is the turbocharger for N04C engine. These are popular in Japan for collection/ delivery vehicles and customer's demand is increasing. Major vehicle with this turbocharger is Dutro(HINO) and Dyna(TOYOTA).
About European Cars
The movement for European cars, the down-sizing engine is popular and almost all vehicles has turbocharger; BMW mini, Volkswagen, Mercedes Benz, Audi, and Volvo as examples.