[Lord Odin]

Leftystrikesback, on Jun 2 2009, 01:06 AM, said:

I was just re-reading this thread and wondered if GrenadeMaster ever did the test on his phantom as he promised? I would be impressed if he got +/- 1 as he claimed, as I was only able to get +/- 7 from my phantom using the best paint I could get my hands on. with HPA I got +/- 16

Here are the results from my own test:
http://spreadsheets.google.com/pub?key=rnA...amp;output=html

CO2 was far more consistent

I'm not familiar with the phantoms but do you have an idea why Co2 did so much better? What was your paint to bore relationship?

[Leftystrikesback]

Quote

I'm not familiar with the phantoms but do you have an idea why Co2 did so much better? What was your paint to bore relationship?

No idea, other than the easy to say, but hard to qualify "the valve was designed for CO2" argument, which I always thought was a bunch of BS.
That's why I was interested if a similar test had been done. I think Bryce intended to do something like this too.

If you look at the data for the HPA, you can see that there are odd outliers where the velocity dropped off considerably. Velocity never spiked, but it dipped from around 290's to 243, then 255, then 269. I don't know why that would happen, but it happened. My tank was at 3k psi, none of my other guns get drops in velocity with that tank (Same one I used for the "holdng the pump handle forward" test, so you can compare the consistency the tank is capable of). The paint was good.

The stock barrel is .690, I was shooting DXS Gold that measured about .684 so I had a fairly large overbore going on. It was the same paint and barrel for both tests so that should have no impact on the relative results.

[brycelarson]

my guess is that it's a sweet-spot issue with the valve.

I would be really curious about what the output pressure of your HPA tank is.

[Leftystrikesback]

Sorry, I don't have a gauge to read the output pressure of my tank. It is higher than the CO2 output because the velocity went up. it's a DXS 4500 psi regulator if that tells you anything.

This post has been edited by Leftystrikesback: 02 June 2009 - 02:16 PM

[brycelarson]

Leftystrikesback, on Jun 2 2009, 02:15 PM, said:

Sorry, I don't have a gauge to read the output pressure of my tank. It is higher than the CO2 output because the velocity went up. it's a DXS 4500 psi regulator if that tells you anything.

might have actually been lower - it's air pressure that holds the valve closed as well as spring pressure. most likely higher, but you can't tell just from velocity.

[Christopher]

I think I might have suggested this in a different thread, but I'll sum it up here.

1. I think that it's possible that the output pressure of HPA tanks are not really as consistent as people believe. However, since the vast majority of modern guns come equipped with a HPR, the actual consistency of the tank regulator is not really important, as long as it's close to the ball park of what you want your actual operating pressure to be. The HPR of your gun minimizes most inconsistencies by regulating the air a second time. But when you put an HPA tank directly on a gun without a regulator, such as the Phantom, those inconsistencies may become noticeable.

2. The uncanny Phantom consistency dealing with unregulated CO2 could be explained by the fact that as a very efficient pump, the Phantom does use enough gas quickly enough to cause noticeable cooldown within the CO2 tank. The cooldown that does occur may be further negated by the heat absorption that takes place during the time it takes in between shots. And if the temperature of the tank does not fluctuate, the pressure will stay exactly the same, resulting in a very consistent output pressure.

It may not even be something that is inherent to all HPA systems. Not all regulators are built equally. It's also important to realize that there really is a regulator on your tank. It sounds stupid, but I really feel like a lot of people forget this. Think about it, how often do you clean/lubricate/replace O-rings in your tank regulator compared to the rest of your gun? Most people never even take it apart, let alone clean it.

I'm really just throwing stuff out there. I'm not sure if I'm wrong or right, but that's the theory I'm sticking to until someone finds a more definitive answer.

Also, here were my results from the test with my Shocker and Maxflo:

http://spreadsheets.google.com/ccc?key=rWp...R-FXN2DoLWkCIjw

This post has been edited by Christopher: 02 June 2009 - 03:27 PM

[RIPB]

anthoneyk123, on 16 April 2009 - 05:36 PM, said:

im saying this right now propane is more efficiant than all

Also more flammable

[wagz86]

Older thread I know... what im curious about is the exact setup ud have to go through to make co2 equal to the consistency of dual regged hpa? Is it as simple as putting in an anti siphon and dual regging the co2 with say for example two palmers stabs? Im experimenting with this myself at the moment and that's exactly what ill do. Its be a 3.5 oz on my empire trracer, an anti siphon, and 2 hp stabs. The final stage one will definetly be a pps cause I have one already. But the initial one will just be a cheaper one im sure cause I don't feel like buying a second.