GAH this engine is full of suprises! - now the blow off valve is opening at slightly above idle, if you hit the accelerator a wee bit, the BOV opens and starts sucking? air.. till it returns to idle again, the BOV is off a VR-4 and is designed to be replumbed, but i have it venting to atomisphere..this may be the sound im hearing at high revs..this seems to have only come along since the reattaching of the breather, increased vacume and the BOV is not up to it/fucked? it has no spring adjustment etc either.