need help with tuning for NOS on LS1

[tony 5.7]

just found out about the site looks awsome.i live in sydney australia and own a vy ute. i have a friend who does tuning on LS1's but ive got the ute tuned to 290 rwkw
the tune is maffless so im not running a maff
my mods at moment
* 228 230 112 cam
* 4000rpm stall
* 3.9 diff gears
* surge tank with twin bosch 044 pumps 60 lbs injectors
* OTR CAI
* NOS efi plate kit up to 250 HP
* 2 3/4 full di philipo exhaust system from head to tailpipe

im thinking of running the 200 HP shot of NOS
i know ther3e is a NOS feature in the efi live tuning software what has my mate need to do to make the tuning on the NOS as he has never done one
i was thinking of leaving the original N/A tune on the pcm and once the nos button is pressed then the pcm will switch to the NOS tune is that possible

thanks

[nevinsb]

Hi, welcome to the forums.

You can take a look here for info on "Custom OS 5":
http://forum.efilive.com/showthread.php?t=7313

[joecar]

Custom Operating System 5 (COS5) contains additional tables for NO2 (and for boost also)...

See more info: http://forum.efilive.com/forumdisplay.php?f=27

COS5 allows a switch input to be wired to the PCM, and when the switch triggers the PCM switches to the NO2 VE/timing tables.

[tony 5.7]

ok ive finished the NOS install now what i need to know is i have to run a wire from either the arming switch or the micro switch to a wire in the ECU for the change of maps when racing from n/a to the NOS tune

here is a pic of the switch and the microswitch

[5.7ute]

Welcome to the forum tony 5.7.
The pin on the pcm needs to be earthed to activate the tables in COS5. What I did was run an extra relay which activates with the nitrous relay, this way timing etc is only pulled while spraying.