Is there any way to make a turbo with an internal wastegate operate on an external wastegate?

im not extremely 100% sure on this one but pretty confident this is right...yes you can run an external wastegate even though your turbo is loaded with an internal...to my knowledge youd weld the spring on the internal wastegate shut and make sure your turbo manifold has a flange for an external wastegate and run it from there...now the part im not too sure on is how to shut down the internal wastegate but im almost positive thats how to run the external wastegate

I just recently read somewhere that you remove the wastegate from the turbo and weld a plate in its place. Anyone know if that works or not?

I think thats pretty much what ivtec is talking about. welding the internal closed and then run an external from an external wastegate flange.

Are internal wastegates as easily controlled and upgraded as external?

you can run more boost with the external

all you do is weld (or somehow hold) the internal gate shut and run it as a standard turbo. You can get a 5 bolt flange for your DP that covers the flapper hole and disables it, you could pull the actuator arm off of the internal gate, or just weld 'er shut and you can use external...

you can run more boost with the external

not necessarily, but you can better control your boost settings and prevent boost creep.

What exactly is boost creep?

you have a wastegate spring (in my case for example) that is set for 10psi. I only want 10psi and that's all i'm tuned for. Boost creep occurs when more that 10psi reaches the turbo and therefor is translated into more than 10psi in the charge side.

Manifolds and WG's both play a large roll in controlling boost creep.

How does the mani help control boost creep? I understand how the WG would.

the placement of the extension for the wastegate is the main reason. Drag manifolds have the WG placed on the first runner...the first runner's boost level is controlled, but the rest of them aren't. The manifold creeps a lot. A good example is the InlinePro manifold (for cast anyway) because the WG is located over the collector and that is the best place for it.

Center versus runner like you said in your 'How To'

yep