mine does get a tiny bit of compressor surge in the upper rpms but i'm planning on getting a larger low off to handle that. about the aftermarket one you have that opens at 20 in of vacuum, you might see more compressor surge with that one because it will open only at higher amounts of vacuum.
you can test the one on there now by simply unplugging the vacuum line from it and try sucking on it while looking at the bypass valve. sounds stupid but you can at least tell if it is opening properly.
you can test the one on there now by simply unplugging the vacuum line from it and try sucking on it while looking at the bypass valve. sounds stupid but you can at least tell if it is opening properly.