by cutting fuel is a big NO-NO. There is always some residual fuel left in the intake runner and if you cut the fuel to reduce the engine RPM, you will cause the cylinders to have a few power strokes of very lean condition. The 350Z uses fuel cut rev limiting, and you would not want to bounce that car off the rev limiter for any length of time what-so-ever. They went to this setup though because of emissions; an ignition cut setup produces a lot of execss hydrocarbon in the exhaust, but it is a very safe way of limiting RPM.