Nitrous Oxide - Temperature affects on n20




View Full Version : Temperature affects on n20


Currdog
04-22-2002, 01:54 PM
Guys,
How much should a difference in temperature affect the actual rwhp output of a setup.

Lets say for arguments sake, the affects of 65 degree weather versus 85 degree weather.


minty
04-22-2002, 06:52 PM
NONE at all. Nitrous creates its OWN atmosphere. The only thing the weather would affect is traction. Thats one of the great things about spray.

383LQ4SS
04-22-2002, 07:29 PM
I wouldnt say that its none at all. Its true nitrous comes out of the nozzles at a specific temp but its combined with the ambieant air as it enters the intake. So lets just say that if you combine 30% of the intake charge that is at -162 degrees F (nitrous)with 70% intake charge that is 90 deg F and then compare it with that same 30% intake charge at -162 combined with a 70% intake charge of 50 deg F...obviously the overall intake charge temp will be lower on the second scenario. Either way the intake temps will be pretty darn low so the difference is minimal. But I do think there would be a difference.

Thats just a guess and not hard facts...but it seems logical?

Oh..and the -162 for nitrous temp was just made up...its something like that though.


minty
04-22-2002, 07:36 PM
You can get as technical as you would like which is why I like this site. But the bottom line is people use nitrous because the only thing that effects how it works it jet size and bottle pressure. Weather plays no part at all in how hard it hits. Thats why you will see a car run the same time over and over again assuming the traction is the same.

rich
04-22-2002, 07:59 PM
this is true in a fuel injected engine that adjusts for ambient air temp. In a carberated motor you would have to jet the carb for the temp. change or just lean on the n20 system for the warmer temp.The ambient temp. dosen't effect a n20 engine as much as it would a na engine. The engine temp. does change the way our engine runs that's why we all buy the 160 t-stat and fan switch mod or a hpp3 for the fan setting

383LQ4SS
04-22-2002, 08:10 PM
Minty...theres no doubt that the difference is minimal..but I would still say there is a difference. All my best times and MPH either on or off N20 always happened in cooler weather.

Chris Spiess
04-23-2002, 01:19 PM
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 383LQ4SS:
<strong>Oh..and the -162 for nitrous temp was just made up...its something like that though.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Wheew! scared me for a minute. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Boiling point is -127.2F (-88.46C)

Country Boy
04-25-2002, 07:53 PM
I asked this before. The way I see it is, the weather shouldnt make a difference. The ambient air will never be lower than the N2O charge. No matter if the ambient air is 90* or 50*. When the spray starts, it cools the charge in the intake. Theres no way that the ambient is going to be lower than -132* (nitrous) <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Take this for example, sort of, take a glass of water thats 50* and one thats 90* and put them in the freezer. Neither will go below 32* (freezer) no matter what temp they started at. Im not talking time, Im talking temp.

383LQ4SS
04-25-2002, 08:36 PM
Thats pretty much my point Carl. That the temp of the charge going into the cylinder is what counts. That temp is comprised of mixing whatever comes out of the notrous nozzle with whatever ambient air comes through the intake. When you spray nitrous in the intake it does not displace all the ambient air that would normally come in. I would guess that a 100 rwhp nitrous shot on a motor that is putting down a total of 500rwhp is probably near 4 parts ambient air by volume to 1 part nitrous. So its always a mix of the two. So the overall temp will be less than ambient and greater than nitrous alone. It all depends on the ratio.

The lowest temp that the N20 would be, would be as it exits the nozzles at -127 degrees. Combine that with ambient air of (for arguments sake) + 127 degrees. Say the ratio was 50% ambient and 50% nitrous. You would get an intake charge of 0 degrees_(Even though the ratio is actually a larger % ambient than n20 for something like a 100 shot).

Now make the ambient temp at 0 degrees. Still a 50/50 ratio. Now the intake charge will be -63.5. A big difference!

There is alot more to this question too. This doesnt take into account the amount the intake charge will be heated as it travels the intake tract (much worse on a hot day). Also I believe there is a point of diminishing returns as far as HP gains VS extremely low intake temp on an internal cumbustion engine.

And then there is the actual difference in temps of the engine and its components including oil and coolant and the affect that may have on a very hot day.

Another way to look at this is scale back the nitrous shot. If all you ran was a 25 shot...the difference between a very cold day and very hot would be extremely evident. A 50 shot..a little less evident... a 100 shot even less..and so on.

Now again...the differences on a nitroused motor will be very minimal. Especially on a bigger shot. But to make a blanket statement that there is ZERO diference, none what so ever, is not possible. Take it ALL into account. The person who asked this question is running a 422 stroker and a small 100 shot. He may very well see a difference on a cold day. A large portion of his HP will NOT be coming from the nitrous charge.

Al

<small>[ April 26, 2002, 12:01 AM: Message edited by: 383LQ4SS ]</small>

Country Boy
04-26-2002, 06:42 PM
Holy crap Al, did you turn into Einstein on us or what?!!??! You do make sence though, I think <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> I was waiting on the I=NxA/5200xS kiind of stuff <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

BTW~ did you ask George for that one? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

383LQ4SS
04-26-2002, 07:25 PM
Carl...Oh hell no. Had I asked George I would have had to copy and paste a book. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />