I have seen it a couple of times on rb25det engines already. Like you gun it in 2nd gear, 4k, 5k, 6k and it like splutters. You think it should do the usual rev-limiter bounce, but it doesn't. It goes like brrr, like engine is running out of breath with very strange sound. Doesn't sound like the coil-pack misfire.
Anyone had this before ? When you rev it in neutral, nothing strange happens it just rev cuts at late 6k. Any ideas what could it be ?