in the K20A3(Si/base rsx) its at 2.5k...then the audible sound changeover occurs at 4.5k..in K20A2 its at 5.5k.....now....the JDM(RSX-R) is the same engine as K20A2 except for tranny differences, exhaust, a few internal things... unless youre referring to the K24A1 which is the crv engine....
