Just thought i'd add that im going down this route also at the moment.
Im rebuilding a 99 2JZ-GE VVTI for high RPM and high power.
Head is being reworked with larger valves, titanium springs. Going for maximum flow.
Crank is being rebalanced, stronger rods and pistons, lightened pulleys and electric waterpump.
Long duration cams with adjustable gears. M3 Throttle Bodies.
Im looking at revving it to 8500rpm where im hoping i'll make some serious NA power.
I've been looking for an aftermarket manifold for a while now so this OBX system interests me a lot.
So you had to modify it to clear the steering? Hummmm, it looks very close though. This could cause contact given a hard corner or heavy load. This is my only concern.
Also im keeping the stock airbox. The INJen looks cool but its something i think that belongs on honda's. The stock box will allow enough air flow for a 500bhp twin turbo, so there really is zero benefit of removing the stock box. I've gone with just a simple Blitz SUS Panel filter, not because i thought there would be a performance gain but more to make sure i had a decent filter in there.
Otherwise good write up and i'm going to keep a eye on this