NITROUS OXIDE ( nos / n2o ) advice forum

I didnt make myself clear on this.
What I was trying to say was, if I draw my 300hp WON shot of gas from a full bottle for a fixed time period, the bottle pressure will drop by X amount by the end of the time period. So regardless of all the gubbin's between my bottle and injector. If the Boss Noss gubbins can actually flow the same 300 shot that my won system does, surely the same amount of liquid will have been taken from the bottle over the same time period. This assumes both tests on full stabilised bottles at the same pressures.
That is the case Perry BUT;
1) Yours would start off by delivering a high volume DENSE nitrous charge
2) Yours would progress to delivering a lower volume DENSE nitrous charge, due to falling bottle pressure.

Whereas the Boss Noss kit (IN THEORY AT LEAST but in REALITY it's not exactly the case) would;
1) Start off delivering a high volume LOW DENSITY nitrous charge
2) CONTINUE to deliver high volume LOW DENSITY nitrous charge, due to the regulator preventing the falling bottle pressure affecting the output pressure.

So if I have my bottle at 950psi with the smart box and nozzle set to deliver at 300psi, in order to achieve my 300shot wont I need to fit a bigger piston jet to allow enough nitrous to flow at a lower pressure to still give me the full 300hp of liquid?
To get 300 HP worth of nitrous through a Boss Noss kit, yes you'd need to fit a bigger piston/jet BUT;
1) That wouldn't be the only part that would need changing, as the WHOLE SYSTEM (especially the 'nozzle') would need up scaling and as stated before to an IMPRACTICAL size - my EDUCATED guess on the required size for the outlet from the nozzle would approx. 1.5 to 2 inches!!!!!
2) Even if the mods were made and a practical size was possible, it would STILL ONLY SUPPLY 300 HP worth of nitrous GAS - NOT LIQUID.

So if I have to flow x pounds of gas in 10 seconds to give me the 300 shot, thats what I need to flow. So the bottle contents must have still reduced by X pounds of liquid in 10 seconds, be it at 950psi delivery pressure or 300psi delivery pressure.
Yes that's roughly the case when BOTH bottles are UNREGULATED & AT THOSE PRESSURES DUE TO AMBIENT TEMPS but even then the 950 psi system would deliver most. However, when regulating the LIQUID down to GAS you'd have to flow MUCH MORE nitrous to make the same amount of power, for loads of reasons but I'll limit it to the easiest to understand;
1) When injected as a LIQUID nitrous takes up less room (and therefore displaces less air), it also exchanges heat with the air which increases the density of the air, both of which result in more power from the NA air, that the nitrous doesn't have to make up for.
2) In contrast, when injecting GASEOUS nitrous, it takes up between 3 & 300 TIMES the volume that liquid does (depending on the end temp) and therefore displace an equivalent volume of air. There is NO cooling (or at best MINIMAL), so there's NO increase in air density and as a consequence MUCH MORE nitrous GAS, would be needed to make the same power as achieved with the same quantity of LIQUID.

Do you see what I'm getting at? If you flow an amount of liquid from the bottle in a fixed time period to meet a demand the pressure drop would be the same regardless of what was between bottle and injector wouldnt it?
NOPE and I hope I've provided adequate info to clarify and prove that for you.

I can see that the density of the nitrous may be lower on the Boss Noss system, so in order to correct this you would fit bigger and bigger nitrous piston jets to achieve the correct weight loss from the bottle to ensure you have flowed the correct weight of liquid to make the 300 shot in the 10 second test period.
Yes but that's ignoring the NUMEROUS other beneficial factors associated with using LIQUID nitrous, instead of GASEOUS nitrous.

Its probably not relevant as I dont suppose this system was designed for flowing amounts like this.
But I do now understand why it was made to fill a niche in the market.
Exactly but even then the end results leaves a lot to be desired.

Do you think fuel freezing might be a problem on a system like this that is being used with such low air intake temps??
Without a doubt, which is why special fuels have been developed for such environments?

What I do now is keep one bottle in ice water.The big bottle is in the truck heating up from the sun. After a run. I remove the bottle from the ice water and turn it up side down and open it up . That freezes it down as the nitrous evaporates .I then hook it up to the big bottle and I am ready to go.
That's a commonly used method but unless you have plenty of time for the bottle temperature to return to ambient THOROUGHLY then it's not a good idea, as the pressure will be unstable.

Usually getting over 1.25 lb of weight into the bottle.
You should NEVER over fill a bottle and that's not just a matter of safety, as you get better flow characteristics from a bottle that isn't entirely full.

Would I need to do this with a two bottle system every run? or could I get more than one run from 40 oz of nitrous?
Regardless of how much nitrous you use per run, you should ALWAYS carry out THE SAME PROCESS before every run, if you want consistent results.
Even if there is enough nitrous for a 2nd run from the same bottle/s, the 2 results will be different and obviously one will be inferior to the other.
The BEST way to fill and use bottles is as follows;
1) Make sure you have enough bottle capacity to be more than enough for one run.
2) DON'T cool the bottles before filling.
3) Rely on a differential in bottle position (height difference) to get a 'DECENT' fill - to do this your main bottle should NOT have a dip tube fitted and it should be held as high as possible above the bottle to be filled upside down.
4) Once the filling process STALLS, take hold of the small bottle and shake it vigerously from end to end and set it back down, until the filling process STOPS.
5) Using this process you SHOULD be able to get approx 15oz in each bottle, which is ideal for optimum performance.
6) By not cooling the bottle there will be less of a heat transfer barrier, which is essential for stable bottle pressure.
7) By filling to the optimum level the gas pocket to liquid volume is optimum, which again is essential for stable bottle pressure.

If so I would need to get 4 bottles?
More bottles is without doubt better than too few, as it gives you more time to stabalise the pressures.

Another option is a 2.5 lb bottle mounted in front of the rear tire. But that will require a custom swing arm.I need to move the rear tire back six inches anyway for better fairing options .
With only six months to go. This is one of the BIG details I need to settle soon.
That's all down to you.

OK so two bottles on the bike. They can mount behind my legs with out much aerodynamic penalty.
The would be best mounted upside down and as high as possible, so your previous suggestion about up at the back of the seat area either side of the wheel would be better.
On the last bike I prepared for myself, I removed the original fuel tank and fitted 2 x 2.5lb bottles there and then made a smaller fuel tank that fitted just uner the elevated ends of the bottles at the front of the bike, as THAT is the BEST plcase to fit nitrous bottles on a bike.

What do you think of the 12.5 to 1 piston profile? I am going to cut some old pistons in half to measure the crown thickness.
I'm SURE it will be thick enough in most areas (but could do with being stronger between the valve cut outs and the top ring lands) and its MUCH better than the high comp piston (which I would NEVER dream of using even NA) but if you fitted a thicker gasket and had the valve cut outs machined less deep and/or fitted a slightly lower lift cam (assuming you can't run the valves any closer to the pistons) and/or pocketed the exhaust valves at least by a few thou, the piston crown could be SO MUCH BETTER.

I am a creature of habit. I like to have a system for doing thing. Not only is it repeatable. But things get exciting at the track. Having a system of doing things keeps it simple.
Exactly right and a good CORRECT system is essential for consistent and good results.

Thanks for the advice about handling nitrous. That is another thing I am also learning about.
My pleasure and if you haven't already had my book delivered, I'm sure you'll find much more useful info in there when it arrives.