Use of the engine exhaust turbocharger

   Turbo is the use of engine exhaust turbocharger drive, since there are thousands of degrees exhaust gas, the need for additional air intercooler to cool the compressed air to a high temperature. The advantage is more efficient than a mechanical supercharger boost, the disadvantage is influence by the engine speed, low speed effect is not obvious, there will be an engine upgrade to the outstanding performance when speed.

     Turbo lag is also facing increased turbocharged engine supercharger display header of the biggest challenges in the instrument. At low speed, the turbocharger is not involved, GT2871 turbocharger but still want to drive the turbine exhaust rotation, no naturally aspirated engine exhaust and smooth, this time the engine torque output than the same displacement naturally aspirated engine still weak.

     As the engine speed increases, for example, after a breakthrough 3000 rpm, turbochargers sudden intervention, the power generated at this time will be increased sharply. This sudden increase in power affects the power output of the ride. Although the turbocharged engine to give more power to bring the output, but as a civilian car, smooth power output is very important, and turbo lag will bring some influence driving comfort.

     Double charging technology to overcome deficiencies

     Mechanical supercharger helps torque output at low speeds, but at high speed power output is limited; and exhaust gas turbocharger has a strong power output at high speed, but at low speed is powerless. Engine designers so they conceived the supercharger and turbocharger together to solve their lack of both technologies, while addressing the problem of low-speed torque and high power output.

     2005, Volkswagen began this technology fitted to the production of civilian cars Golf 1.4TSI, the system is called "double booster", taking into account the low-speed torque output and high-speed power output. GT2860 turbocharger At low speed, are provided by most of the mechanical supercharger boost pressure at 1500rpm, while providing both the turbocharger boost pressure, the total pressure reaches the value of 2.5bar (if the turbocharger alone only can produce 1.3bar of boost pressure).
     As the speed increases, the turbocharger enables the engine to get more power, at the same time, the mechanical supercharger boost pressure is gradually decreased. Supercharged by an electromagnetic clutch control, which together with the pump. When the speed exceeds 3500rpm, provide all the supercharging pressure by the turbocharger, supercharger case completely separated under the action of the electromagnetic clutch and the engine, to prevent the power consumption of the engine.

     1.4 liters of Golf "double booster" (Twincharger) engine in the dual role of the turbocharger maximum output power of 125kW, maximum torque of 240Nm. From 0 to 100km / h just 7.9 seconds. 1.4L 2.5L engine power reaches the level, but the fuel consumption is reduced by 20%, the average fuel consumption of just 7.2L / 100km. At 1750rpm on the issue of the maximum torque 240 Nm, and up to 4500rpm. The advantage is suitable for all conditions. The disadvantage is that the structure of the complex, dynamic performance at high speed region is not prominent.

     Explained by Volkswagen, the performance was not the main appeal of this engine, power output smoothness and economy is the key. It seems the other major car companies are not pushing this technology because it lacks a distinct personality. Go home