Cam retarding?

[Shane@DBPerformance]

Most of the things you do with adjustable cam gears to help spoolup can hurt topend power a lot. That's the beauty of systems like MIVEC where you can change the cam advance/retard vs rpm/load.

Most of the the things you listed above could very slightly improve spool up, but maybe not enough to notice, unless your exhaust is really restrictive of something. A tubular manifold usually adds a decent amount of lag. An OEM or FP style cast exhaust manifold will normally drastically outspool a tubular, longer runners, bigger runner manifold. Your best options are to get smaller turbo, get a bigger motor, use nitrous, or just rev higher.