Low Pressure Mod for Xvalves ?

[going_home]

I was wondering if any of the mad scientist mag enthusiats out there are working
on a low pressure mod for mags.
To me the only chink in the armor so to speak of the Xvalve is its love
of air.
I can only go a whole game if my tank is at or above 4000, so when the
day cranks on and the fills get lower and lower as it typically does at the
fields around here, I have to drag out the Ego.
It would be nice not to have to keep a high dollar low pressure backup marker.
It'd be nice to only own mags.

[Cow hunter]

a low pressure mod for mags is a phenominal idea, but then wouldnt it just become an aluminum classic valve of sorts? i always thought the high pressure was to increase reactivity increasing recharge time, i could be wrong though

[REDRT]

It'd be nice to only own mags.

It is really nice. You otto try it. ;)

[Hexis]

Well, what's the goal? Better efficiency or shooting deeper into a tank?

[scrumpy]

The high recharge rate of the x-valve thrives on high pressure, lowering it would only starve the marker. I'm not sure but I think Tom Kaye hates the idea of low pressure and turning a mag into an LP marker is something like heresy and you will be burned at the stake.
Low pressure does not equal shot to air efficiency. When you have low pressure air you need to move more of it to get the same velocity shot as a high pressure marker, meaning you have to have high flow, high volume parts. Air efficiency comes with marker design and consistant ball to barrel matches. Shooting deeper into a take doesn't mean that you have better efficiency; to get an idea of the efficiency of each marker: take a tank, fill it full and shoot as many 300 fps balls out of it as you can with your mag, and then with your ego do the same.
Smart Parts tried to lower the pressure of the classic valve using the magic box and later the "smart valve" and succeeded slightly, but it only hurt the recharge rate of the valve and not much else.

[SummaryJudgement]

Why do you need "high-dollar" guns to shoot low pressure? You could get a decent mech cocker for a couple of hundred dollars these days. Or even a real nice one (used) for a little more, I see them all the time on Ebay. I have lots of cockers and most of them shoot between 200 and 300 psi :D

EDIT:
Heck, even Tippmanns can the pressure down these days.

[RapidTransit]

Low Pressure ≠ Efficiency, High Pressure = Greater Potential for Efficiency I have an idea why this is true, but lets wait till someone with a degree in fluid dynamics explain this one. :rofl:

[Dark Frost17]

not using such a large bore will help, for that paint you use :D and a barrel atleast 8in befor porting starts......
Where you using .693 or so freak back and with like helfire paint? :confused: .....

:D
:cheers:

[thefool]

low pressure just lets you shoot deeper into the tank. and if you field is filling to 3000psi, that means you hp tank has ~2200 vs ~2600 for an lp tank. Thats roughly a 15% difference in usable air. Then if you say that hp is more effeciant, say you get 10% more off a tank. Thats about an extra pod of paint that you get out of lp.

[m-a-r-k-7]

Low Pressure ≠ Efficiency, High Pressure = Greater Potential for Efficiency I have an idea why this is true, but lets wait till someone with a degree in fluid dynamics explain this one. :rofl:


Someone quoted Tom as saying this is true in a thread in Deep Blue. So... I'm going to believe it.

[BigEvil]

You guys are all forgeting, the pressure chamber in the mag < 400psi when the ball is fired. The high pressure is behind the on/off, not forwards of it.

The mag needs the high input to reset the sear. Im sure that the reg was also designed to work with HP, but if you eliminate the need to push the on/off pin back then you can talk about lowering the input pressure.

[Cow hunter]

You guys are all forgeting, the pressure chamber in the mag < 400psi when the ball is fired. The high pressure is behind the on/off, not forwards of it.

The mag needs the high input to reset the sear. Im sure that the reg was also designed to work with HP, but if you eliminate the need to push the on/off pin back then you can talk about lowering the input pressure.
instead of having the sear reset by a high pressure difference behind it, might it be magnetically assisted to lower the necesaary to reset pressure?

[Asym]

This has been brought up a lot in the past. But your asking for a classic valve. To make it run at an even lower pressure you need a larger volume of air between the on/off and bolt. This was tried like was said above by smartparts with the black box. Do you want the LP so you can shoot deeper into the tank?

Just curious how much do you shoot if you need over 4k to get through 1 game? On the classic I use as my main I'm getting around 1000 rounds with a 68CI 3k tank, I can keep shooting untill I get under 500PSI left in the tank. This also has level 10 installed which is supposed to hurt efficiency.

[nate2k191]

wow, this thread is great, i love ao.

I fill my tank a lot too. its a 68/3k and its drained by my x-valved e-mag that can lay down some heavy fire. i was just thinking of getting a 4500 tank...

[StygShore]

Crossfire 92cu 4500 tank.... only thing I found to get me through a full day of play with the mag without filling nitro


Styg

[BigEvil]

instead of having the sear reset by a high pressure difference behind it, might it be magnetically assisted to lower the necesaary to reset pressure?


That issue can probably be bandaged by having a two way noid or ram. Push and Pull. But then you might have timing issues with the on/off pin.

[SlartyBartFast]

If efficiency means more shots per fill, TK has said it before. The answer is HIGHER chamber pressures.

There was a thread about filling the chamber to attain this.

If you want to shoot lower into the tank, why? How low you go into the tank is only important in two cases:
1 - you actually get more shots per fill.
2 - your field can't give you decent HP fills.

[nicad]

The sear does not requite a "certain" amount of pressure to operate.
The lvl7 mags ran at 380-400 psi for 300fps.
the lvl10 can require as much as 600psi for 300fps.
This is what the chamber runs on just to get the ball up to velocity.. anything extra you give it in a higher output tank will start affecting the reactivity, recharge rates, etc.

What was changed from the lvl7 to lvl10 to require the higher pressure?
smaller bolt stalk -> more restriction on air flow to fire ball requires more pressure to ge past the restriction. The bolt spring was optionally upped as well, so more force to overcome that requires more pressure.

At 0.55ci, the mag _should_ be able to run at 300psi if all of that air is used and done so with a high enough flow rate.

[hitech]

At 0.55ci, the mag _should_ be able to run at 300psi if all of that air is used and done so with a high enough flow rate.
Yup. We just need longer effective length barrels. ;)

:cheers:

[RapidTransit]

Has anyone ever looked into making the power tube ID bigger with a new bolt. Maybe someone can jump in with a good surface area vs pressure formula. Heres a wild idea with an adjustable air chamber size start the day with HP, and a very fast recharge rate and as the Air dwindles adjust the chamber for more volume o get deeper into the tank.

If the chamber were smaller and the inner diameter increased of the power tube increased, would this cause faster recharge rates and less air?

[hitech]

Has anyone ever looked into making the power tube ID bigger with a new bolt...If the chamber were smaller and the inner diameter increased of the power tube increased, would this cause faster recharge rates and less air?

I believe that would all work. However, making it is a lot more invloved than it may sound at first. You still need enough room between the inside wall of the bolt and the power tube that it doesn't become a restriction. To get it all just right might require custom sized orings, resulting in a higher cost. But, yeah, I think it would work. If I win the lottery I would try that as an one of my projects to improve the 'mag...

:cheers: