I know with an internal wastegate the excess exhaust gases that aren't needed to spin the turbine are just vented into the exhaust. But with an external wastegate where do the gases go? Are they just released into the engine bay?

 

it is released out the exit of the wastegate into a dumptube, which usually exits below the oil pan to keep the engine bay cleaner, or you can route it back in the downpipe

 

mine dumps right in the cabin, i have a pipe that comes out from the floor board and aims right toward the driver, it keeps me warm on cool nights

 

i heard that helps with breathing also, clears the lungs or something

 

The dumptube on my Integra runs to *looks for turbo setup... realizes he is NA*. Nevermind.

In all actuallity though, it isn't too hard to have the dump tube route back into the exhaust system. Some people leave it open, others tie it back into the system... your choice.

 

open dump tubes generally make more power because they do not disrupt the flow of the exhaust by not being routed back into the exhuast and it technicallys makes your exhaust piping bigger. its also much louder. its like running an open downpipe when you hit full boost

 

That and with an open downpipe you can scare the **** out of inicent bystandards beside you when you go WOT.