Nitrous questions

[stroker mike]

I would like to run nitrous and I never have before, and I settled on the performer kit from edelbrock, it has three levels of boost, 50,75, and 100 horsepower. I figured I'd start conservatively, 50 hp shot. Now, I am aware of the need to retard timing for the application of nitrous to prevent detonation and severe mechanical failure, but who can tel me how much retard has to be applied? I don't want to have to twist my distributor every time I want to hit the button, I have a MPP orange box ignition, how do I set up a retard with this ignition, it doesn't have a map sensor, either, how else can I tell how much boost I'm running? I know you retard 1-1.9 degrees per lb of boost, but I am an absolute beginner here, so if anyone can clue me as to what I'm up against, that would be appreciated! I called Jeg's and a nitrous plate for mopar six pack is 339.00!!! Ouch! But I am gonna do it anyway. I just gotta make sure I understand exactly what I am doing. Thanks!

[fastnos]

Not sure about the nitrous plates from Jegs, but a few years back, I bought a setup from NOS. It was a 150 shot, hidden. Think the cost for that kit was almost $ 450 thru a place called "SUPER SHOPS" I plumbed it myself in a couple of hours. Here's a couple of pictures of it. You could only see 2 lines coming out of back of intake when installed. Mostly covered up with Distributor and wiring.

Bad thing about it, You had to pull the intake to change the jets. I started with the 150 jets, and when it hit, it broke loose the tires pretty easy in first 2 gears. Then, I only would (try to) use it only in 3rd & 4th. That seemed to work better. Was fun, but I never really got the sixpack dial in before messing with the NOS. Always seemed to have problems with the carbs. Amost a year later, I bought a brand new 6-pack setup and only did a few minor tweaks to it. It ran real close to the other setup with nitrous in the 1/4. I blame that on my ability to (not) tune the used setup.

[stroker mike]

HOLY MOSES that is CLEAN! I admire your setup that is awesome! How did you set up your timing??

[ehostler]

boost??? Nitrous does not perform boost. Even if you had a MAP sensor, it would have no idea that nitrous was being used.

You might want to look into the Jacobs (now Mr. Gasket) Nitrous MaterMind.

I have also never heard of retarding your timing, when you expect to use nitrous. Then again, I have never used it (never will) and have only known one person that did use it (a bow tie guy).

[TK]

Well, I have heard of retarding timing, but not much on a Mopar. I never have ran it before though..........a buddy of mine does, and he uses a alchohol shot with the NOS, instead of gasoline.

[MrChemist]

A very general and safe way to tune is retard 2 degrees for every 50 hp added. Since you said you are new to nitrous I will throw out a few more things you should have to make the system run safe.

You should use a good ignition system with a hot spark (like MSD). Use a spark plug that does not have a long protruding strap (like NGKÂ’s, around a -7 for small amounts of nitrous)Â…you will need colder plugs as you increase the amount of nitrous used. With a 50 shot you should be fine with premium pump gas, after about 125-150 shot you should be mixing pump gas with race fuel (100+ octane, or just use strait race fuel) to stabilize the burn and prevent detonation. Get an electric fuel pump capable of supporting the motor and the nitrous system (or plum a dedicated system). Do not use a mechanical pump.

Since nitrous is an oxidizer, it just wants to consume things (like fuel) and be happy; however, if you donÂ’t give it enough fuel, it will consume what ever is availableÂ…like spark plugs (if youÂ’re lucky) and pistons (if you have no luck)Â….speaking of pistons, DO NOT use hypereutectic pistons with nitrous, they tend to crackÂ…forged pistons only (and quality hardware on the

[stroker mike]

Thank you MrChemist, I found a box made by msd last nite that will retard the timing proportionately for me thru the use of a map sensor and adjust the mixture of fuel and nitrous. I am going to go to the Jacobs website and read up on their nitrous mastermind, though, I had been considering using their fire control ignition anyway. eHostler, nitrous does perform boost in that it increases the amount of oxygen in the cylinders which is why a map sensor is used to monitor the air/fuel/nitrous mixture and keep it in safe perameters. Without retarding the timing you risk detonation and with such an oxygen rich mixture you could easily blow a hole in the top of your pistons! It is a different type of boost, as oppsed to forced induction,i.e. turbo or blower, but it will allow me to run several tenths faster or more while retaining it's manners under normal driving, which is important to me, cause my cuda is a driver, and my only other transpo is a 96 Nissan Quest for all these little creatures running around my house yelling daddy all the time. (what's that about?LOLOLOL)

[fastnos]

Originally Posted by stroker mike

HOLY MOSES that is CLEAN! I admire your setup that is awesome! How did you set up your timing??

Well, back then I would leave the distributor loose enough I could grab it with both hands and move it. When I went up to the track, KCIR, I'd give it a little twist to retard it. Never put a timing light on it ever. Then before leaving, I'd try to put it back in the same spot. Had 2 notches ground into the base for the hold down clamp in the spot for normal driving. I'd move it some, then rev it up. If it pinged, Id move it more until I thought it had enough retard in it. Would've been more consistant with a timing light, but back then I thought I knew it all, and no one could tell me different. Sometimes I wouldn't get it retarded far enough and get a spark knock, so back in the pits I'd pop the hood and give it a little more "twist". Didn't use it on the street much tho. I'd go thru a bottle on a friday evening and then have to do without on Saturday @ the track or try to have it filled before going there.
If I had that setup now, I'd let all the electronics take care of it for me. I had just the factory ignition back then, nothing elaborate. Just a Accel coil for the aftermarket stuff.

[daredevil]

Wouldnt the proper term be cylinder pressure as boost is pressure in the intake not cylinders.

[daredevil]

I hope this isnt a numbers matching motor that youre learning on as a mistake would be very costly. Most of the sprayers I know learned on cheap 350s and beefed up the bottom end.Start small and watch plugs between passes as they will speckle with metal material when low fuel large shot is occuring.

[stroker mike]

I may be wrong (usually am, according to my wife! LOL) but I thought boost was anything that increased the amount of oxygen or mixture in the cylinders. Now, I am nothing more than a sincere amatuer, here, so I am here for school, believe me. My combo is a late police interceptor with some milled j heads. definitely not #'s matching. I can't afford costly mistakes, which is why I will research this until I have an extremely accurate understanding of everything I'm doing, to minimize the occurance of stuff destroying itself in my cuda. There was a time when I'd run anything, see what happened, but the value of a dollar earned is much more apparent to me at 40 years old, father of 4, you get my meaning. I don't plan to experiment, I will leave that to R&D departments at tracks all over the country, and listen to the voice of experience first and foremost, which is why this website and others like it are so priceless to me.

[daredevil]

The plugs always tell the story . watch them and good luck to you. Remember a lot rich is better than a little lean when youre running the spray.

[dust]

Originally Posted by MrChemist

to stabilize the burn and prevent detonation. Get an electric fuel pump capable of supporting the motor and the nitrous system (or plum a dedicated system). Do not use a mechanical pump.

Informative post but hwy not use a mech pump and a dedicated nitrous system?

I assume 'dedicated system' means to have a pump for the nitrous in it's own circuit.

[ehostler]

Mechanical pumps are too unstable. Even with an electric pump for the fuel solenoid, if the primary fuel system leans out due to low fuel supply, you will melt something. Many people run dual electrics. One for primary fuel supply and one for the fuel solenoid.

[MrChemist]

Yup, E pretty much summed it up. Smaller nitrous systems can get away with pluming the fuel right off the engines main supply line. For safetyÂ’s sake, larger nitrous systems should use a dedicated fuel system with its own pump and fuel line strait from the gas tank.

One more reason not to use a mechanical pump on a nitrous motor: The arm that actuates the diaphragm in the pump can “float”, just like how valves start to float at high RPM…can you say KABOOM!

I personally use a Holley blue pump (really noisy, but it works) that provides 14 psi from the pump, then I cut that down to 6 psi at the regula

[stroker mike]

Excellent information, gentlemen, thank you! Btw, I emailed jacobs ignition about timing retard/nitrous and they said for 50-75 horse shot you really don't need to retard timing, if mixture is correct, i.e. not too lean. I looked at nitrous mastermind, may be more than I need for a small kit, but hey, it's kinda cool lookin', ain't it? I am gonna try to keep it simple, and safe as possible till I learn the ropes with this bottle business. I don't think I'll mind the noise of the fuel pump, if I can hear it over the resonance from these flowmaster 40's, jeez! I might have to get some other exhaust to tone down interior resonance, cause it's so loud at certain rpm I can't hear myself think.

[ehostler]

As the old joke goes... If it's too loud, you're too old!

[Dick]

Originally Posted by ehostler

As the old joke goes... If it's too loud, you're too old!

ehhh? What?

[stroker mike]

my car audio buddy just called me and said "that's why they make dynamat" and hung up on me! I guess he read this thread!