i'm not sure on that.. but this is what i read on i-club
| 引用: |
|
This is big news. Subaru, until now, has always used a constant-pressure type turbocharger. In constant-pressure turbocharging, Subaru uses a relatively large volume uppipe to damp out the mass flow and pressure pulses so that the flow to the turbine is essentially steady. It appears the turbocharger used on the new STi is a pulse type turbocharger, which is specially designed so that much of the kinetic energy associated with the exhaust blowdown can be utilized. Relatively small volume header pipes are used. The small cross section maintains the desired high gas velocity and concomitant kinetic energy to the turbine inlet. If all four cylinders fed into a single pipe, the separation between the pulses (180 crank-angle-degrees) would be too tight and they would interfere with each other. To solve that, the four cylinders feed into two pipes and the turbocharger has a divided turbine inlet with the division maintained throughout the turbine housing all the way to the end of the nozzle section. This keeps the cylinder exhaust events within each half of the divided housing spaced apart 360 crank-angle-degrees. The net benefit of pulse turbocharging is faster spool up and a steeper boost curve. Pulse turbocharging is rarely seen in gasoline powered cars but I do know that the Mitsubishi Lancer rally car uses one.
|
maybe they changed the turbo design when they designed the GDB?
:shrug:
平板模式
