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n2extreme1 08-25-2012 02:26 PM

Lowest pressure using stock phantom,inline reg and Hp
I know the phantom likes a pressure around 800 psi. For those of you using HP and only changing out the spring in the phantom for Hp how low were you able to drop your input pressure from your Inline reg and still keep it around 275 fps?

Dr. VonDeafingson 08-25-2012 07:09 PM

I'm not sure I understand your question. Are you talking about the tank reg or another inline reg like a cp or stabilizer? Because a phantom doesn't have a regulator.

A description of your setup might help.

Legolas 08-26-2012 12:40 AM

I have a "vsc" style gauged phantom with a male stab (in place of the bucket changer) going to a bottom line air tank. Stock hardlines between valve and vertical ASA and between stab and bottomline ASA.
I have stock springs, SSC lightened bolt, open-face TPC. 12" Deadly Wind Fibur Barrel, tymcneer brass inserts. My gun runs between 550 and 800 psi depending upon where the TPC is set and I generally try to shoot between 285 and 300FPS(field limit). Typically the TPC is usually set to its lowest spring pressure settings.
When adjusting the reg I find that increasing the preasure beyond 550 psi decreases the FPS, and sometimes it is only by decreasing PSI that I can achieve playable velocities.

n2extreme1 08-26-2012 01:13 AM


Originally Posted by Dr. VonDeafingson (Post 2455256)
I'm not sure I understand your question. Are you talking about the tank reg or another inline reg like a cp or stabilizer? Because a phantom doesn't have a regulator.

A description of your setup might help.

Sorry. I meant an inline reg like a cp or stabilizer.

Dr. VonDeafingson 08-26-2012 09:18 AM

Dropping your input pressure should increase your velocity (to a point) because the lower pressure lets the valve stay open longer. To low and you won't have enough pressure to propel the ball.

funsi00 08-27-2012 06:03 PM

My setup is PPS phantom stab output pressure 500 psi with blue main spring and silver valve spring

Hans 09-17-2012 10:46 PM

It really doesn't like to go below 450psi or so, from when I last tested it out. Below that it starts having issues, and I can't recall even getting one to function at all under 400psi. It's been a few years to be honest.

The issue is twofold. Powertube ID and spring tension.

You can only get so much flow through the powertube, and as you lower the pressure you need to increase the time that the cupseal is open. This means moving to a lighter valvespring, and usually a lighter mainspring too.

But if you go too light on the springs and pressure, a couple problems start popping up. First is that you get 'nelson bounce' on the hammer. Remember, the cup seal depends on both spring pressure and air pressure to maintain a seal. Softer springs and lower pressure allow the weight and momentum of the hammer to have a greater influence and it starts bouncing on the powertube. This turns your efficiency to garbage real fast once it occurs. You can somewhat compensate for this by lightening the hammer, but there's not much hammer in there to work with.

Then you start running into recocking issues, as again the cupseal is dependent on air pressure to maintain its seal. Not enough air pressure backing it up means it can't fully resist the force of the mainspring and instead of cocking the hammer, you just force open the cupseal.

If you wanted to go for a low pressure setup, you'd have to turn a powertube with a larger ID, then open up the hammer and bolt to match. Not so easy on a Phantom with the bolt design it runs. Even then, it's a crapshoot that may not pay off.

Nelsons just really like high presssure.


toymachine 09-18-2012 08:33 PM

I didn't have to change anything other than adjust velocity normally to get my ghost running at a comfy 650psi. Setup is with ninja 850 output tank and sidewinder set to about 675psi. I find it's a good idea to keep output of my inline/secondary reg about 200psi lower than its input. then again, a ghost is not a phantom, so not sure how much this will help.

on my hpa run phantom I have basically the same setup, but clipped (1 coil) blue valve spring and green mainspring and run it off a stab at about 675-700psi. seems to like reg'd co2 better than hpa, but hpa is just so much more cost efficient atm. the only really noticable diff from stock was a five shots or so increase in efficiency and better consistency (well, better in that it's more consistence further into the 12g, which would only make sense... not really a difference consistency wise until the 15-20th shot into the 12g).

idkfa 09-27-2012 05:58 PM

I had a Phantom down to 425-450 psi shooting 280 fps. The problem became valve popping. There was so little spring force and gas pressure in the valve that every single pump stroke opened the valve. I was thinking of installing a screw in the pump rod channel like on the Gargoyle to prevent over travel, but the safety mechanism gets in the way.

I abandoned the project and returned my Phantom to a regulated medium to high pressure setup. It shoots better anyways, and isn't finicky.

dardagnan 09-28-2012 02:08 PM

My phantom 410 psi => 280 fps
sorry my English is verry bad
Phantom et pompe souple |

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