How is it supposed to work? A throttle body spacer is designed to straighten the airflow snaking through the crooked plumbing of a vehicle’s factory air box and intake tubing. The idea is that the straightened flow is much more prone to efficient atomization, pairing better with fuel molecules and burning more completely than before. Some spacers even offer another twist: a machined vortex pattern in the surface that swirls the incoming air, much like the integrated parts in GM’s Vortec engines (you’ve probably also seen this in products like the Tornado).