I am new to gassers and have a G23 with a velocity stack. I have the stack's angle slanting back. (high side in front and carb is upright and out in the airstream). This G23 was mounted on it's side. Most everybody tells me to angle it forward. I read some old posts..........AND I remember hot rods with their stacks slanted back, so that is the way I did it. Am I wrong? (I'll bet this will open a can of worms) .... thanks, ..lownslo...
Bob

try it both ways and tach it, your mileage may vary. with my homelite 25 it works better pointed forwards... the difference isn't much though.

I've got a G23 mounted inverted in my 1/4 scale biplane, & oriented the tallest part of the stack UP, only reason being that way it matched the curve of the round cowling. Works great, looks like it "belongs" there, & is easy to put my hand over for drawing fuel into the carb. From the threads I've read, I'm not convinced that the orientation is a big deal; the fact that a velocity stack is ON the carb will help in itself. Just my $0.02 worth. -Daniel

I have found each application to be different.