I would recommend both.

http://en.wikipedia.org/wiki/Wastegate

http://en.wikipedia.org/wiki/Blowoff_valve

You need to control the RPM of the turbocharger, otherwise you can have catastrophic failure. Hence, you need a wastegate.

Your logic, is not logical. wink

My Syclone did not have a BOV from the factory & would get compressor surge when closing the throttle valve, sounds kinda odd when it does this. Not really good for the turbo.
The excess pressurized air is actually going backwards through the turbocharger when the throttle blade is closed.

Puts a load on the turbo also.

I installed a larger compressor wheel & then I installed a BOV to be on the safe side, plus will have less tendency of blowing off couplers, hoses, clamps etc, when using a BOV.



MBHD

BTW, we needs pics of your progress.

12 port SDS EFI