Last stage of the test complete. I had 15mm holes and it sounded OK - quite raspy though. I increased the size to 20mm and then to 25mm. Big difference. At 15mm you could hear it at idle and a little over that. At 25mm you hear all the time. Much deeper sound and louder.
I have updated my video (apologies for the sound of rain in the background in the last 2 tests) but I think the camera toned the sound down so if you listen to all 5 x recordings they sound the same loudness. In fact, the last one is at least twice as loud as the first.
Porsche Boxster 986 Crios Mod 2 - YouTube
2003 Porsche 986 3.2s Tiptronic
Threaded Mode
