i have the 75hp nos dry set up, and it work fine for me and very simple. and someone said before always use 91 or higher. ive also add a octaine booster just incase and never had any problems pinging or knocking.
but what ever kit you use a purge is a must good to have
some ppl have said to up the timing to 14 but i have gotten best result (track times) with it at 10. so playing around with the timing and the fuel pressure to get the best results
but to the original question, if yo wanna feel safe when using nos, 100 hp shot would be the most, without upgrading anything eventhough highly recommended to upgrade the fuel system and air delivery a bit. but anything higher than 100 shot and i would recommend upgrading fuel pump, injectors, etc...
boy it had been a while since i posted, that felt good, just been browsing latly
I live within 10 miles of our local drag strip.... I know of at least 20 people using nitrous personally as am I. NONE have a purge on their system. The only reason any of us would want one is for "show" - I personally purge in the water box right quick. Then I do a "dry" purge on the way home (with the bottle off) to clear the lines.
Save the $120+ on the purge and get a bottle warmer if you live in cooler climates. That's the one thing I don't have and wish I did.