The QR25 rev limiter cuts fuel. No late model OEM car cuts spark, it would be very damaging to the cat. Its common for race cars to cut the spark. Mike --- Joshua Gary <ewraven@hotmail.com> wrote: > I'm in a little debate right now and am sure that > one of you guys can solve > it. I remember keeping up with a long discussion > over whether the QR25 rev > limiter cuts fuel or spark.