Overclocking ECU

[Ivan141]

With all respects ZDo, but that really sounds unlikely and not like a good way to change the revlimit.
I dunno what method the ECU uses to measure RPM, but if it is altered by clock freq then it is very likely that other things will change with it, and that would give unpredictable results in the engine management.

If you're really interested in changing the inner workings of the OEM ECU then I'd suggest contacting the guys that have done the research (r.hellenbrand for example).