External wastegate vs "ported" dual wastegate ports?

[JStieger]

I've noticed more and more twin sets using the S300 top turbo being used without an external wastegate.



Is this because the Enlarged "ported" dual wastegate ports now available with these S300 variants, such as what HTT or II sell, offer similar performance as an external wastegate?



Or is an external wastegate still the preferred way to go for ultimate performance?



It sems like when I look at those ricer Fast and Furious type magazines and see the cars profiled that most, if not all, of them use external wastegates in their twin turbo set-ups. Yeah... I know... ricer versus diesel. :-laf . . but still we want to use exhaust energy efficiently don't we?

 

[Jim Fulmer]

I can only think of a few cases were I would still add and external gate to the mix. I have personally seen 48 psi from the bottom turbo in a twin setup built like this, you tell me if it works! No it was not a ported housing, just an original sixed SPS 66.



Jim

 

[nickleinonen]

if you can get the necessary flow from an integral wastegate, it should work ok. the ricer turbos have much smaller turbine sections, and their internal wastegates are much smaller than ours. .

 

[Forrest Nearing]

actually, their internal wastegates are of similar size, but if the turbine housing is sized to spool halfway decent, they'll end up overboosting... our engines are much more forgiving to high boost...