>I have seen all techniques mentioned above used by Sport Compact Car Magazine (yes, this pub. is a guilty pleasure of mine). I like this publication because they dyno EVERYTHING.

Hard to argue with that -- the dyno is a pretty good hype elimination device. And I have seen some pretty wild things tried by SCC when I have picked it up at the newsstand. One idea that I liked (it may have been on the 300ZX you mention) was injecting solidifying structural foam liquid into the A-pillars for reduced noise and increased rigidity (and it apparently worked well!).

>What's so special about the RENNtech intake other than it being carbon fiber and really expensive?

I have to pass on that question; no idea.

>How about computer upgrades? Anyone have any luck in this dept.?

I am running Neil's custom M119 chip, and it offers definite driveability enhancement, as well as perceptibly more power at WOT. I won't speculate about horsepower or torque figures.

>Ignition upgrades? Are there any avaiable?

Larger coil? Magnecor or Nology wires?

>Headers with free(er) flowing mufflers - though I dislike extra noise

Several people have noted that a replacement of the center resonator with a Y-pipe gave them freer flow with minimal increased noise.

>How about advancing timing?

I suspect that would be a bad idea on a vehicle that's already been chipped, as the spark curve is already pushed up.

s/b