SE Turbo Wastgate
Posted: Fri Apr 17, 2009 8:15 am
Ooh. What is the logic for this?
What will it achieve? How is it done?
EDIT
I found this info;
"The wastegate's role is simple - to bypass excess exhaust gas that would otherwise over-speed the turbocharger and cause overboosting.
Most production turbo cars are equipped with a turbocharger incorporating an internal wastegate. These integral bypass passages are generally less than 20mm in diameter and, as a result, aren't capable of flowing a huge volume of exhaust gas. This can cause high-load backpressure on the engine and - even worse - lead to the possibility of an overboost on a modified engine.
Enlarging and smoothing the internal contours of the bypass passage is one method of improving the flow through an internal wastegate. Expect only a small increase in flow, however - due to the relatively thin casting, the diameter of the bypass cannot be greatly enlarged.
In instances where maximum wastegate flow is required, an external wastegate must be fitted.
An external wastegate serves the same function as an internal wastegate, except it's a separate assembly with bypass pipes typically between 32 and 52mm in diameter (ie much larger than any internal wastegate). The fitment of an external wastegate requires a large diameter pipe to be tee'd into the manifold prior to the turbine housing. This usually requires the fabrication of an all-new custom exhaust manifold.
The traditional application for an external wastegate is on monster horsepower engine, where a huge volume of exhaust gas must be wasted to prevent overboost."
What will it achieve? How is it done?
EDIT
I found this info;
"The wastegate's role is simple - to bypass excess exhaust gas that would otherwise over-speed the turbocharger and cause overboosting.
Most production turbo cars are equipped with a turbocharger incorporating an internal wastegate. These integral bypass passages are generally less than 20mm in diameter and, as a result, aren't capable of flowing a huge volume of exhaust gas. This can cause high-load backpressure on the engine and - even worse - lead to the possibility of an overboost on a modified engine.
Enlarging and smoothing the internal contours of the bypass passage is one method of improving the flow through an internal wastegate. Expect only a small increase in flow, however - due to the relatively thin casting, the diameter of the bypass cannot be greatly enlarged.
In instances where maximum wastegate flow is required, an external wastegate must be fitted.
An external wastegate serves the same function as an internal wastegate, except it's a separate assembly with bypass pipes typically between 32 and 52mm in diameter (ie much larger than any internal wastegate). The fitment of an external wastegate requires a large diameter pipe to be tee'd into the manifold prior to the turbine housing. This usually requires the fabrication of an all-new custom exhaust manifold.
The traditional application for an external wastegate is on monster horsepower engine, where a huge volume of exhaust gas must be wasted to prevent overboost."