You must have an absolutely 100% reliable fuel system than can supply enough fuel for the NOS without dropping pressure, vapor locking, etc. A "T" behind your stock mechanical fuel pump is not going to cut it with a 150 kit.
You need to pull out 2 degrees of timing for every 50 hp if you're running pump gas. It can be done manually, but performance off the bottle will suffer, or you can do it via a seperate or built in automatic timing retard.
A fuel pressure cut-off switch is really mandatory IMHO. If you go lean, you WILL burn a hole in a piston.
Don't ever, ever hit the rev limiter while on the bottle. Your intake manifold may be found in the next state. Most people use a "window switch" to prevent this form ever happening.
That's all I can think of for now.
Hey Ramcharger, great info on this...ive ben thinking about some squeeze for my 340 too...would the type of internals make a difference on how much you would be able to spray? lets say i have a 340, 10.5:1 cr , iron heads and wanted to spray a 100shot...would i be able to go more and avoid detonation or should i run less?
What pistons are you using? Big doses of nitrous require forged pistons, hyperutetics can handle up about a 150 shot and stock pistons can go up to a 100 shot ASSUMING EVERYTHING ELSE IS CORRECT! The rods, crank and bottom end also need to be built to handle the total amount of HP you will be making with the N2O.
Also, N2O is not a cure-all. If you have timing, jetting, vacuum leaks, etc., it will only get worse when you're on the button and result in engine destruction. The engine must be in perfect running condition, then 2 degrees of timing must pulled out for every 50HP added by N2O. If you're not detonating now and pull the correct amount of timing, you should be fine but should check your plugs after your first runs to confirm it.
You can pull timing out in two ways. Manually at the distributor or automatically via an ignition box that has this feature or a seperate nitrous controller. If you do it manually, you'll most likely be down on power until the button is hit. The auto boxes are the ****, lol. They sense power on the lead to the solonoids and pull a pre-seat amount of timing. I like the Mallory 685 box. It incorporates a window switch, auto timing retard and a two stage rev limiter and there are no chips to buy.
A window switch is great when used in conjuction with a full throttle activation switch. The full thottle switch activates and sends power to the box, the box then will not allow power to the solenoids until a pre-set rpm limit is hit, then will cut power at another pre-set limit before the rev limiter is hit.
Oh yeah, never hit the N2O until at least 3000 rpm.
oh and why does hitting the rev limiter while on the bottle destroy the manifold? thats something ive never heard before and am curious to know more:read2:
the low fuel pressure switch is wired in to pull the grounds off the nos and fuel solenoids to shut the system down, not just shut the fuel off.
wow guys real great info from everyone here...definatly all great advice to keep in mind for running nitrous...my bottom end consists of forged pistons with .30 overbore(i think they are speed pro but im not sure), forged crank, and factory reconditioned rods...I am going to be running the 685 box from mallory regardless due to the two step and me running a stick, and that nitrous retard feature is a great part of it that i always thought would come in handy some day...i figured id have to run a high octane or race fuel in my car if i wanted nitrous (or any other power adder for that matter) since my cr is quite high...just trying to get an idea of what i would be looking at for nitrous and the info has helped...maybe one day ill strap on a 150 shot and play!
wow guys real great info from everyone here...definatly all great advice to keep in mind for running nitrous...my bottom end consists of forged pistons with .30 overbore(i think they are speed pro but im not sure), forged crank, and factory reconditioned rods...I am going to be running the 685 box from mallory regardless due to the two step and me running a stick, and that nitrous retard feature is a great part of it that i always thought would come in handy some day...i figured id have to run a high octane or race fuel in my car if i wanted nitrous (or any other power adder for that matter) since my cr is quite high...just trying to get an idea of what i would be looking at for nitrous and the info has helped...maybe one day ill strap on a 150 shot and play!
10 hp?
He's got forged pistons.. They are the weak link. Spray away dude. That setup will handle 250hp with the right fuel and ignition systems to run it. When I mean "stock" lower end I typically mean pistons. Because the other parts in a Mopar are plenty beefy. The pistons are too, but can't handle a lot of tune up error (as in lean or too much timing or too hot of a plug). You've got no problem running what you want to with what you listed.