Hi, I'm getting boost creep with 9.8cm turbine housing. Is 38mm external wastegate good enough? It seems like 38mm = 11.3cm2 which doesn't seem like a huge difference from 9.8.

OR can I actually use both internal and external wastegate??

Thanks in advance

 

FWIW, I like a dual gated(one integral gate, one remote gate)setup personally. I adapted and used just such a setup for years on a Buick Turbo Regal V6 GN and it is a great setup in general.

I think that it is overkill for a stock 16G VIII turbo though and that you would be better served by porting your existing 9.8cm turbine housing, upgrading to a ported 10.5cm housing, upgrading to a ported tubular O2 housing, or running an O2 dump. Any of these simpler, cheaper solutions should prove sufficient to control the measly 3 PSI of creep that you are experiencing.