I would like to see two things regarding throttle body spacers on the JK 3.8:
1. An explanation as to how it promotes mixing of fuel and air, when the fuel isn't injected until just before the intake valve. By then, any turbulence imparted to the air by the throttle body will be dissipated as the air travels the length of the stock intake.
2. A real dyno readout from an average JK owner who installed one, where it is the only mod since a previous dyno.