Modding a hipac for efficiency

[antithesis]

I know, before anybody says anything about safety, remember how rough the QC on these were to begin with🙄. What I plan on doing is to port the outlet into the valve, as well as valve intake, in the interest of maintaining more valve pressure during the shot cycle.

Firstly, does this follow sound logic, increasing flow into the valve to raise the average pressure during the shot?

And second: I'm really not sure how much to open it up but it seems anything would help. This is definitely the most robust part of the unit so I've got room to play, so knowing I've got more than enough valve retention, I want to know if anyone can see any reason NOT to do it that I may have overlooked?

[rsterne]

Increasing the size of the interface between the HiPac and the valve will increase the force on the valve screw.... Tread carefully....

Bob

[mobilehomer]

What are you trying to achieve? I have a 2400KT/HiPac, 18" barrel, disco TP, Marauder poppet in stock valve. With a 2000psi fill, I get 30 22 fpe shots with JSB 18.1.

[antithesis]

Increasing the size of the interface between the HiPac and the valve will increase the force on the valve screw.... Tread carefully....

Bob

Oh I've considered that... honestly if I hadn't made this setup around a hipac already I'd just go with a standard tube fill, I got upgrade screws on a cothran tube, it's plenty robust for this in terms of valve retention... but is my logic otherwise sound as far as you can tell?

[antithesis]

What are you trying to achieve? I have a 2400KT/HiPac, 18" barrel, disco TP, Marauder poppet in stock valve. With a 2000psi fill, I get 30 22 fpe shots with JSB 18.1.

This is a case of never leaving well enough alone really...but the more I thought about hipacs in general, they will never quite achieve the efficiency of a standard disco type setup because of limited plenum space..I already have an extended  valve to help and even had a longer tube than the original 2250 cut just for it. I want to see how much performance I can wrench outta her.

In for the penny in for the pound they say...

On a side note that sounds pretty impressive from a 2k fill, 18" barrel, and a 2400/2250 hipac...no extension? What's your ending pressure if you looked?

[mobilehomer]

What are you trying to achieve? I have a 2400KT/HiPac, 18" barrel, disco TP, Marauder poppet in stock valve. With a 2000psi fill, I get 30 22 fpe shots with JSB 18.1.

This is a case of never leaving well enough alone really...but the more I thought about hipacs in general, they will never quite achieve the efficiency of a standard disco type setup because of limited plenum space..I already have an extended  valve to help and even had a longer tube than the original 2250 cut just for it. I want to see how much performance I can wrench outta her.

In for the penny in for the pound they say...

On a side note that sounds pretty impressive from a 2k fill, 18" barrel, and a 2400/2250 hipac...no extension? What's your ending pressure if you looked?

I forgot a couple things in my first reply. SSG and 1 extension. The SSG helps tremendously. About the same number of shots as my Maximus with very similar power. Ending pressure is around 1000psi. It's hard to tell because my fill valve is inaudible. I read the pressure jump when it opens.

[antithesis]

I found the old SSG assembly I had been working on previously, and as much as I wanted to keep the rva I have for the sake of aesthetics, I may just have to give it a go. The dead blow hammer I got from MAP gives no PERCEPTIBLE hammer bounce (and I'm still not sure how it functions exactly), but I'm sure there is some, even though I'm running a short heavy spring allowing free flight. Id really like to be able to switch to something with an adjustable striker pin, the SSG should definitely make that possible. I'm aiming for a 30 ftlb average with medium heavy ammo (think barracudas), so I need everything just right if I'm to expect a decent shot count without stretching the curve too far