I don't know about that, it depends on the builder/tuner. There is way more RB knowledge and experience in Japan then there is elsewhere, just like the rotary. It's blasphemy in north America to talk about 400+ rwhp on pump gas from a rotary, while over there it had been common place to go past 500 rwhp on straight pump gas since the late 80's all on stock parts, without moronic mods like dowel pinning and depleted uranium apex seals.