So I've decided to subject my little Suzuki Samurai to some home-spun garage surgery. Converting to a full sequential MPFI. (and doing a little porting along the way). Now for the physics(ish) bit. See image of intake cutaway. The blue arrow points to the sharp ('cut -off') trailing edge of the narrowing before the valve. Ignore the red writing. My understanding is that the narrowing should function as a Venturi, aiding in particular low-rev (i.e. day to day performance - esp torque). I definitely want to retain this 'low-end' performance (hence simply grinding away the constriction is not an option). Regarding the treatment of the sharp edge - 2 options: possibly champfer it very slightly, and rely on a 'Kamm tail' type effect to flow it towards the valve. The other option would be to fill-in the 'squared out' defect (with e.g. Al powder epoxy), resulting in a smooth, variable radius curve... the flow would then 'Coanda' it's way directly towards the valve curtain area. And no, I haven't run a CFD sim. I'd like to see what other people's aerodynamic instincts are. Thanks all.