# Secondary Butterflies **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [February 6, 2007, 6:42pm UTC](https://forums.speedlife.net/t/secondary-butterflies/24175 "2007-02-06T18:42:13Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![MHill](https://avatars.discourse-cdn.com/v4/letter/m/ea5d25/32.png) [@MHill](https://forums.speedlife.net/u/MHill)\ **Post date:** [February 6, 2007, 7:18pm UTC](https://forums.speedlife.net/t/secondary-butterflies/24175/2 "2007-02-06T19:18:23Z")
From what I can recall and the quick research that i did, Your power gain should have been down low. The secondaries when inactive are normally open. This creates a shorter intake primary for increased efficency at higher RPMS. When functioning properly on a stock ECU VTEC should engage at 4400 RPM and your butterflies should open at around 5600 RPM. With an intake and not a rediculasly loud exhaust you should be able to hear a distinct change in engine tone at each of those RPM points. So to change what your looking for, you shouldnt feel a difference at higher RPM only lower RPM. --- _[View the full topic](https://forums.speedlife.net/t/secondary-butterflies/24175)._