Rev Limiter

When I first joined the list there was a thread finishing up on how to disable the rev limiter. I have a 1.8L 16v now and I've never had the V/C off so I don't know if there are cams for sure, but I was told there probably was some type of performance cam installed and it also runs like it has a cam. I am also upgrading to a 2.0L with ported and polished head, intakes, TB, portmatched intakes, exhaust, Cams, etc and would like to know how to disable the rev limiter. The 1.8L set up I have now seems to sag off at around 6500rpm and up to that point seems like it wants to run stronger at higher RPM! Please let me know!