I was wondering if I used 105 octane if I would really need to retard my timing with a 150 shot? Would that work or would I still need to retard it? thanks

 

I still would, it's safer and when you are on the spray you might even pick up power.

 

Answer is YES! For every 10 HP gain, retard the timing 10 Degrees.

 

retard 1 degree for every 50 hp shot, 105 octain is fine

 

how the extra fuel and nitrous is added to incress volumetric effincency, there would be a need to retard the timming as such because it would take longer for the charge to burn obveously. the spark plug gap should also be considerd. if running a stock ignition you might notice it will start to missfire @high RPM, even at a 50hp shot, if the plug gap is to large the spark will acctualy crap out because of rpm/extra fuel/nitrous. i suspect you are running a MSD so a lack of spark is out of the question. running a .007 max smaller gap will help.

i ran a 150hp (who knows actually the hp) with no detonation or any other "pre-meltdown" problems as they say. but every engine is different. bore size, as far as total timming for that can vairy +/- 4 degrees. alot of stock engines can run nitrous without any other engine modification. i see alot of people going crazy, jetting their car higher or leaner to go faster until the limit and then some. when they blow their motor they blame the bottle. and not thier impatence.

i hope this helps. i know i rambled on but someone eles might need it. good luck

 

as long as you have a good fuel and spark setup...i would get a plug that is 2 steps colder than stock and run 110 fuel.
drop timing by 2 deg. you'll be fine. make sure your running proper bottle pressure as well at all times. you'll want around 900psi to 950 psi.
and adjust your fuel pressure "flowing" with the proper matching jet while your flowing .