Originally Posted by somers
I have an EXALT reg grip on my 08 and CSL and both are +/-2 over the chrono with no issues what so ever.... the hole in the HPR is to allow for venting should your HPR "super charge"....
The hole in the side of the reg is there to allow the atmospheric side of the regulator piston "breath".
As the regulator piston moves up and down the volume of atmospheric air inside the regulator body changes. When the piston is up, the volume is large. When the piston is down, the volume is small. The hole just allows atmospheric air to flow in and out of that chamber so as that that side of the regulator piston is always at a consistent, rather than varying pressure.