The VR Throttle body spacer is just that. A spacer, no swirl tricks etc? We have found in honest testing on a running engine using a clear PCV neck, that the swirl effect that most companies are after is not actually occurring to enough of a degree to create a turbine effect in the intake manifold. We do see them giving the air structure, reducing the turbulence created by the air induction and throttle body, this also increases velocity. The VR spacer has small ridges that help straighten airflow, also reducing air turbulence and increasing velocity. Here is what most spacers are doing, they are increasing the plenum volume of the intake manifold, and this keeps the engine from having to pull on the throttle body or air induction system as hard. This gives the engine a larger plenum to draw its air from at each firing cycle, so velocity in the intake manifold is increased, because it does no longer have to rely as heavily on the throttle body or air induction system for air at each given firing cycle. The swirl spacers that did work only did so in certain parameters at 1/4-1/2 throttle and once the throttle was opened to WOT and RPM raised some created turbulence, others showed some flow increase. This became more a function of each spacers design and the application it was being used on ex. High RPM low RPM etc.. The item that always became clear was that a straight spacer with vanes designed for straightening airflow was best overall for performance, fuel economy and ease of production. The end result is a much simpler spacer that is cheaper to produce and can be made out of a wider variety of materials. This throttle spacer is for 2005-2007 C6 Corvette LS2 only. The power gains we have seen are throughout the curve. The LS2 applications see around 5+rear wheel horsepower and 10+ ftlbs of Torque! Keep in mind this is on a completely stock vehicle. The torque is what we were after as this leads to a much broader overall power curve and gives you power you can feel. As always, modified applications yield more power from this spacer. The power gains we have seen are throughout the curve. The C6 LS2 applications see around 5+rear wheel hp and 10+ftlbs of Torque! The torque is what we were after as this leads to a much broader overall power curve and gives you power you can feel.