Engine Management
When going for significant HP increases, particularly with any kind
of forced induction, engine management  (timing, fuel mixture,
valve timing, etc) becomes an issue with the stock system.  This is
where aftermarket engine control units come into play.  The AEM
system was the first true "plug and play" ECU designed specifically
for the NSX.  After almost ten years it's become a bit dated but
with upgrades to the newest software it's still a good unit although
not the only choice in today's marketplace.  In addition to all the
basic and advance programmable control features the unit also
has a built in data logger for other inputs that you may or may not
choose to actively participate in any control function.  The 5 that
I've incorporated are air/fuel mixture, exhaust gas temp, fuel rail
pressure,  intake air temp and oil temp.   Some of these are
redundant as the original ECU monitored them (air temp for
example), but it's always nice to have a second opinion.   
Here's one exhaust gas temp sensor from AEM that
interfaces directly with the ECU.  I have two, one for
each bank of cylinders.  Once the proper calibration
file is loading into memory it ready to go.  
In my case I had to machine up some exhaust
header bunges and some sensor adapters as shown.  
This mounts the sensor to the collector and allows
the probe to protrude into the exhaust stream.   
My  air/fuel ratio is sensed by twin wideband O2
sensors also mounted to each exhaust header
collector.  The sensor signals in this case needs to
be processed by a separate controller as shown.  
This processed data is then forward to the main ECU
for use by the engine management system (closed
loop if desired) , sent to a dashboard display or in
car computer, or just logged for download later.  I
typically log the data directly to my in car laptop
computer via an RS232 connection as I have
virtually no limit on how may parameters I can log
or for how long (digital memory!)  
Here's the two sensors (exh temp & O2)
connected to each back at the collector.
Note custom oil temp sensor/drain plug in
pan.   The O2 signal is prone to some RF
interference so I shielded the harness all
the way to the control unit.
A fuel pressure sensor and some
custom adapters to mount it to my
fuel rail.  Again, some calibration
data and basic wiring to the main
ECU and is ready to send data.
A quick shot of my fast response intake air temp
sensor.  I mounted it directly into the air stream
entering the intake manifold.  The stock IAT is
mounted IN the manifold and due to thermal
momentum and heat soaking issues it doesn't always
read correctly.   
Sometimes you just want a warm feeling that
everything is operating correctly so I added oil and
air temp gauges in the cockpit.  The small switch to
the right of the oil gage is for turning on the stock
pre-amps  so I can connect my IPOD to the system
as I removed the stock stereo/CD changer  to save a
bit of weight.   Hey, you need tunes at the track,
right?   All the other stock creature comforts remain
(heater, AC, Power windows, etc).