NITROUS OXIDE ( nos / n2o ) advice forum

Here's something interesting for you to chew on, lets see what you can deduce from this;



For now I'll tell you, that everything is the same for all 4 except the outlet end shape.

Now you can't deduce anything specific about what is causing the differences but the smart guys out there (which obviously excludes Tubez & Co - LOL), should be able to make a general deduction that applies to every aspect of a nitrous system, so lets see who the smart guys are.

Here's a clue, it confirms one of my main theories and I promise not to laugh at anyone who tries but gets it wrong, as it's high end stuff.

Oh and there's more of this kind of R&D results to come, it's just finding time to do the editing.

the one on the left spreads wider, earlier, and is more regular/less "jet in the middle" like.

I'd like that one please

It looks like the two on the left have a flowstream that quickly jumps from the diameter of the pipe to about 3x the diameter, whereas the ones on the left appear to keep a constant diameter after leaving the outlet.

-BC

The length of the liquid core is different! The one on the right has a sorter tube therefore less phase change takes place before the nozzle exit.

The last one from left to right has more liquid nitrous comeing out and is under more pressure then the rest???

Not going to make any comment on if its better but the far right has a denser, more constant plume. (Its easier to look at these images if you copy them into paint and invert the colours.)

yes i would agree id pick the far right for my system.....is it really the same size outlet on the "injector" trev?

Brian it's about exit design. Just like jets need to be radiused properly or how a funnel shape works much better than a flat panel with a hole.

the one on the right looks like it has 2 outlets - one where the plume starts and one (hidden by the plume) at the same height of the other tubes - though that may just be a factor of the outlet? - probably the advanced one? hard to tell. Does look denser for longer too.

Though I don't have an inlet that long and would rather have it wide as early as poss to fill the inlet with nitrous; rather than dragging air in with the narrow plume. And it all bouncing back out round the perimeter of the inlet (when the valve is shut) as the jet of nitrous forces its way down the middle. If it forced it's way down the whole inlet wouldn't it hold itself in there as such, and build up in pressure... less air dragged in too?

but then I'm new to this (ex US kit lover ) and get things wrong lots

air has less oxygen than nitrous and I'd rather keep that out

I'm not sure why.. but the one on the right has the least abrupt plume shape. I'd think this would give more time for the nitrous and fuel to mix?

Although.. none of us spray in an open atmosphere. I wonder what effects an inclosed chamber with curves/sweeps has on this?

Rich

I've been away for a day sorting things out for my trip to the USA on Monday so I'm very pleased to see so many educated responses.

Maybe I should have given a few more details as that would have prevented the one or two incorrect responses that have been posted.

First EVERYTHING except the shape of the exit is exactly the same on ALL 4 tests, otherwise the test would be meaningless and I've got better things to do than fabricate bullshit stories.
The pressure is the same, the solenoid flow rates (without the pipes) are the same and all pipe lengths are the same (in and out).

The reason the end one has an extra part fitted is because it was easier to machine the desired internal shape than to flair the copper pipe to such extremes. There are no unseen tricks being used and the copper tube butts up cleanly and perfectly to the alloy nozzle, so there is no internal change of diameter causing the different plume shape.

You've all spotted the differences and most of you have made appropriate comments but none of you have yet picked up on what core theory (of mine) the results support.

Dave,

You're right the left does spread wider but not by enough to make it your best choice but I still have some ideas on how to achieve that, without the negative effect that option suffers.


Bob,

Well spotted.


Carnut,

You're right about the liquid core and less phase change but your reason is wrong - very good try though.


Donkeypunch,

Correct observation but wrong reason, the pressures were all the same another good try though.


Daveg360,

Correct observation.


Brian,

Yes the only difference is the shape of the outlet but this has created one or 2 other changes besides the intended one;

1) The pipe length at the constant diameter is unavoidably shorter
2) The end bore is unavoidably larger

However there were 2 aims of the test and these results prove we're on the right track with both;
1) We wanted to see if the outlet shape affected the spread of the plume.
2) We wanted to determine if the shape of internal changes in diameter of the nitrous flow path affected the density of the nitrous flow.

I believe that the unavoidable changes may have had a minor influence on the result but they are not the major cause of the changes in plume shape and I'm confident that's due to the shape of the change in diameter.

Wise choice by the way and this or better will soon be in use on some very quick vehicles.


Denny,

Correct, although as I said above there is more to it than that, as it leads to confirming one of my main theories!


So more theories then please.

HI Trev.

Here is my guess !!!!!!

The one on the right looks like it has a tighter, longer or narrow spray pattern and greater EXIT pressure , which I assume would result in a more consistant and predictable spray pattern producing better atomization with less chance of phase change .

Just an uneducated guess !

John

All correct, especially the phase change, although I can't confirm (or otherwise) your statement about the outlet "pressure", however we certainly believe that the outlet velocity is higher but we have no way of proving that at present.

What should be obvious to everyone is that the exit shape of the hole affects the density/phase change.

I wonder if this will be enough proof to silence the FOOLS who think that a hole is a hole, is a hole

When you take the concept to its ultimate conclusion and bear in mind that a nitrous system is a series of holes, it should also be obvious that not only are holes different but so are nitrous kits!!!

I'm not sure how much it effects this... but. When I was a fireman, one way to stay cool was to create a fan shape with the nozzle. This creates a low pressure area right in front of the plume which helps to draw air accross your good guy fireman


If the plume was placed and shaped properly I could see it aiding to fill a chamber with air. Don't know what that would do to the NO2/fuel mix though?

Rich

That's one of the reasons for the R&D work, so well done. ;-)

The aims are;

1) minimise phase change.
2) reduce flow losses.
3) generate a plume that pushes on the largest area of inlet charge.
4) generate a plume that pulls the maximum amount of charge from behind it (your suggestion).

Plus, to determine the effect that changes in flow path diameter (and how they are achieved) affects both flow and density.

Trev,

What effect ( if any ) do you think the differences in weight between nitrous and fuel has on atomization ?

I'm not sure how to take that question?

However what I will say is that I believe fuel is better atomised when supplied through the OEM injectors, than it is through most if not all combined nozzles and I don't believe it's best to inject the fuel and nitrous close together.

The vehicle we've been doing this R&D work for, is having a UNIQUE internal direct port "dry" system, which I believe will produce outstanding results as it encompasses all the best practice principles.

Having said that, some if not all of this technology, will also be applied to Dave Bailey's Pro Mod bike and our growing number of customers using our new and unique high end systems.

I think what this shows is Trevor has too much time on his hands!

No Pavlo, what it shows is my attention to detail and it's ALL those small details that add up to make the big difference between my nitrous products and any others.