Reverberation refers to the moments of the intake/exhaust cycle when the intake valve of one of the cylinders is closed for firing. When this happens (at 6000 RPM, it happens 100 times per second!), the velocity stack can no longer suck air into the combustion chamber and a great deal of turbulence is created as the air being sucked in hits a wall.

This condition has been a problem since we began to tune engines in the search for more power. There is no way around it so we’ve learned to live with the limitations it causes. That is, until recently…

Thanks to the work of very talented engine head designers- and some observant people who were able to recognize the benefits of other’s mistakes- we know now that introducing a slight misalignment element to the inlet flow of air into the intake tract will help to decrease the effects of reverberation.

Velo Stak is the first velocity stack maker to incorporate a specifically designed piece into the Velo Stak to replicate the action of the misalignment. The result of this addition is a moderate reduction in the turbulence caused by reverberation and an increase in both air flow and air stability.