As promised, here is an update on the NX nitrous install. Hopefully this won't kindle up the fire like my Ragnorak wing install
After ~5 1/2 months, the system and car are still running perfectly. I've been testing the 75 shot, and the motor has been very receptive. I find this is the most common shot used by various Celica tuners. I've refilled the bottle 6 times, averaging about 8lbs per fill.
Additions since the original post:
1)Bottle warmer w/ pressure temperature regulator (opposed to thermostatic). You can set the sensor to heat the bottle to exactly 1000psi...it's much more accurate than thermostatically controlled types. The warmer is absolutely necessary in cooler climates to maintain nitrous pressure, which being low could result in rich fuel mixtures. I also added an LED to the gauge bracket (at the bottom, 3rd photo) to indicate the warmer status. This was just an additional safety feature for visual monitoring of the heater from the cabin.
2)Remote electric tank pressure gauge. I like now being able to monitor the tank pressure while driving the car. I removed the mechanical one on the bottle. A sender is mounted on the tank, along with the warmer sender with a dual-manifold adapter.
3)Voltage gauge. Having a smaller PC625 battery, I was concerned I may have to return to stock for the bottle warmer. This ended up not being a problem...the drycell handles it well. Even without the heater, I think a voltage gauge is not a bad idea to monitor overall electrical health.
4)Bottle blanket. Helps to insulate the bottle and provides some cosmetic improvement. My wife stitched on a Lotus patch. The blue color (NOS brand) isn't really ringing my bell, so I'm looking for a black one.
For the gauge/sender wiring, I ran shielded cat 5 cable from the gauges to the boot. It routes fairly easy by removing the center console and feeding through the spine, around the driver's seat, then through the firewall. The hardest thing I ran into was finding an accessory 12V source under the dash. I ended up using the wire that feeds the indicator light on the emergency flasher button...worked perfect. Everything installed very clean, with no exposed wiring.
I ended up *not* installing a purge system (purges nitrous line). Normally with a front mounted engine and trunk mounted bottle, you have a nitrous line which is ~15' long. Since the Elise bottle is near the engine/intake, I bought a custom 3' line which IMO leaves relatively negligible amounts of air and vapor in the line. I've also switched to cooler plugs to help return the spark plug tip to a safer operating temperature more quickly - in between or after nitrous use. EDIT: Here is a good site with some nitrous FAQs:
http://www.go-fast.org/z28/new_to_nitrous.html