[QUOTE]Originally posted by redsscamaroboy:
[QB]johnster,for what it's worth , you should keep the bottle pressure below 1100 psi or it will turn from nice liquid form into a gas and give you less of a gain. i was told that by a friend that sprays his GTO and runs (7's),so i trust him.

I do not believe that... the bottle pressure is changed by bottle and ambient temp. the warmer the bottle the higher the pressure. NOS changes from a liquid to a gas when released to the atmosphere due to ambient temp.. i can not remember the rules of latent heat and other stuff i learned years ago in refrigeration.. but same rules apply... thats the whole reason for purge valves.. to bring liquid NOS to the solenoid.. if the NOS is not used right away it will turn into a gas again..due to the ambient temp of the line, solenoids and such. the bottle pressure does not change its state... Not saying there may be other things at work but bottle pressure will not change NOS state...

 

Actually Wes...according to some...nitrous will "phases shift" from a liquid to a suspension at anything over 1150 psi. Dont ask me the physics and dont ask me to verify that as fact. What I have noticed..pick up a 15 lb bottle (longer than 10 lb) that is half full and around 1100 psi or less and tip it back and forth so the liquid flows from one end to the other. You will feel the weight of the liquid nitrous move from one end to the other as expected. Now try it with the same bottle that is at 1300 psi. It feels like there is nothing in the bottle sloshing around. Bottle is same weight..just seems to me the liquid may now be in a different state. If it is...the density of the exiting nitrous flow will be less.

However...if in fact nitrous does shift properties at approx 1150 psi..i still think its ok to spray a dry 5177 kit with bottle pressure 1150-1175 psi max with no ill effects on power. Heres why. If in fact the nitrous is more of a suspension with a bottle at 1175 psi..when the nitrous noid is opened and nitrous starts to flow toward an opening...the pressure will drop some due to Bornoullis Principle (as flow increases pressure decreases)...reconstituting the nitrous in a liquid form. So in order to have negative effects you would have to be even higher...say 1250-1300 psi before you may see a loss of flow.

I very well could be way off base here but thats my story and im sticking to it <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
I have dynoed on nitrous quite a bit. I have always seen increases with higher pressure on the dry kit. Very noticable gains in power between spraying at 950 and then 1050. Same gain seems to come from 1050 to 1150 , anything above that and it seems to level off or reduce performance.

But...running at such high pressure has other downsides....there will be more of a pressure drop when spraying from a higher starting point. It would be better to keep pressure down to say 950 and use a bigger jet to flow the same amount of nitrous.

Just a few ideas and thoughts to throw out there!

 

383LQ4SS Exellent information,thanks <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

We ran Johnsters car again tonight with the bottle pressure at 1000 1100 & 1150.The car broke into the 7s with a 7.96 the best time.It picked up from last week but some of that could be the new exhaust we put on last week.The 02s were a little lean at 890s but no kr on the gas.I think we are gonna put a translator on it and tune a little.

 

hey guys got the psi up to 1100 or so.the car ran better.the best it went before the bottle heater was 8.08.with it, it was 7.95 does this sound right or not.you guys are still raning faster.one guy on here said he went from a 8.30 to 7.40 same dry shot of n.o.s.

 

johnster,i am glad your "7" showed up finally. I did run 7.8 with a 115 shot and nittos with a 1.75 60 ft. on a stock exhaust and stock convertor.But everycar is different.I converted to a wet kit and ran a 7.6 with 1.74 60ft,love the torque boost.i went from stock "motor" run of 83 mph saturday to 91 mph on spray.Also went 13.71@101 with 2.01 60 to a 11.97@113 with 1.74 60ft on spray. What are your 60ft times? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by johnster:
<strong> does this sound right or not.you guys are still raning faster.one guy on here said he went from a 8.30 to 7.40 same dry shot of n.o.s.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">that was me 8.3 to 7.4, what was your 60ft.?

on my 8.316 run i had a 1.825 60ft
on the very next run (spraying) i went
7.417 with a 1.582 60 ft.
i launched on the gas and pretty much dead hooked.
the front tires came up about 2 inches.

i think alot of it is my st3500 it loves nitrous!!

 

my 60's were about 1.82 on a 100 jet so i guess that is about right for my car.

 

A few thoughts:
Pressure, temperature, and volume of the container all will affect the state of N2O. Since the volume of the bottle is not changed if you increase the temp you will increase the pressure. Nitrous changes state to a gas when released from the bottle because of the large pressure differential between the atmosphere and inside of the bottle. In its normal state at ambient pressure and temp N2O is in its gaseous state. It has a very low boiling point. So to change it to a liquid you must either lower the temp to below its boiling point or increase the pressure. The higher the pressure the more flow thus the more nitrous through the jets = more power. N2O changes state at the jets ideally. Too high a pressure and flow however, and N2O may change state across any other restriction like a bottle valve and I believe this is what causes the peak in power. I do not believe it could change states inside the bottle under even 1500 psi unless the bottle was REALLY hot.