I am planning to purchase T28 or GT28 and they all seems to come with internal wastgate. And if you plan to use external wastgate, is it possible to use internal wastgate turbo and take off the internal wastgate and use external wastgate??

 

You can weld the flapper shut on the internal gate.

 

which sounds the best? i think i'd wanna hear my turbo spooling, but wastegates are loud, sometimes drowning the turbo's out. so which is the best sounding, external or internal or welding it to the exhaust?

 

I was helpin my friend with his SRT-4, it was pushin close to 400hp. so we took a motorcycle exhuast(from a honda i think) and welded a pipe to it, then to the wastegate. the muffler was in a cutout in the bumper. got the idea from Sport compact car a few years ago.

 

The two sounds arent mutually exclusive. I had IMO one of the quietest turbocharged cars.... but when you step on it, you still heard that awesome turbo spool and scream, and of course when you let off, you get the wastegate flutter followed by the BOV whistle.

In terms of sound, it doesnt matter if you go internal or external, but the external is louder. In terms of performance (where it hsould matter), external will be more pricey but less maintenance in the long run (talking about boost creep issues and what not).