I guess so. I'm using it as such with slight porting to increase flare. There also the theory of the air travel being slower with the additional angle as compared to straight up v.stack which air travels in an "L" shape rather than "U".
They do work as air horns, they increase the length of the intake runners and hence increase torque. Many people here on the BB have experimented with aftermarket airhorns and have usually come to the conclusion that they lost some torque. Thats what we noticed on a Sud too.