Quote from: PikeP on June 10, 2020, 06:34:35 PMQuote from: FuzzyGrub on June 10, 2020, 06:23:15 PMQuote from: PikeP on June 10, 2020, 05:49:58 PMIn my findings, the difference between a regulator with a very restrictive orifice that marginally feeds your plenum opposed to a larger orifice that feeds your plenum enough to act as a partial auxiliary plenum, is noteworthy, even more so as you increase caliber or power output. The smaller the plenum is relative to your power output, the more noteworthy. Even in my configuration, with 53 cc, my peak output is currently 64 fpe at sub 2k regulated only because my plenum is partially fed by my reservoir during the shot cycle..if I were to plug my regulators feed holes to where the air flow was negligible, I would likely have a power output of 59 fpe being sub 2k psi regulated...Having listened to Bob over the years, the gold standard of 1cc of plenum to one FPE of output, echos in my head. But have definitely gone down to 1/2cc per, with good results. In your case, it seems like all the work on the reg, only saved about 5cc's of plenum. Bumping the reg up 50psi would be the next option. Offhand, just doesn't seem worth the additional design/testing effort. We all have our areas we like to dig in on. Just for clarity. do you build your own regs, or modifying a production one? Some of the pictures you posted looked like Lanes, but haven't used that one. I use lanes, but I plan on modifying his piston one day to allow a larger od seat / more air flow during the shot cycle in the future...but for now I am very happy with the overall design..Fwiw, your estimate on 5 cc's is wildly wrong, as well as 50 psi...to hit the numbers that I do, most people will run 200-300 more psi than I currently do..provided their reg isn't feeding the plenum well enough during the shot cycle. I would also have to double my plenum volume to be able to hit the 64 fpe again if I were to plug my reg so it cannot feed anything into my plenum during the shot cycleBelow, pictured on the left is a plenum that is fed very well during the shot cycle by the reservoir, on the right, one that is not...the closer to 1 cc per fpe the less noticeable this effect...but for very small plenums, this effect is quite dramatic. (1975 regulated, 19.5" barrel .225" porting (.23" valve that transitions into .225" barrel port) 53cc plenum 33.95gr jsb)Sounds like something that could be interesting for JSAR Raptor HP (.257) and JSAR Raptor 357.....but also to boost the unregulated operation.
Quote from: FuzzyGrub on June 10, 2020, 06:23:15 PMQuote from: PikeP on June 10, 2020, 05:49:58 PMIn my findings, the difference between a regulator with a very restrictive orifice that marginally feeds your plenum opposed to a larger orifice that feeds your plenum enough to act as a partial auxiliary plenum, is noteworthy, even more so as you increase caliber or power output. The smaller the plenum is relative to your power output, the more noteworthy. Even in my configuration, with 53 cc, my peak output is currently 64 fpe at sub 2k regulated only because my plenum is partially fed by my reservoir during the shot cycle..if I were to plug my regulators feed holes to where the air flow was negligible, I would likely have a power output of 59 fpe being sub 2k psi regulated...Having listened to Bob over the years, the gold standard of 1cc of plenum to one FPE of output, echos in my head. But have definitely gone down to 1/2cc per, with good results. In your case, it seems like all the work on the reg, only saved about 5cc's of plenum. Bumping the reg up 50psi would be the next option. Offhand, just doesn't seem worth the additional design/testing effort. We all have our areas we like to dig in on. Just for clarity. do you build your own regs, or modifying a production one? Some of the pictures you posted looked like Lanes, but haven't used that one. I use lanes, but I plan on modifying his piston one day to allow a larger od seat / more air flow during the shot cycle in the future...but for now I am very happy with the overall design..Fwiw, your estimate on 5 cc's is wildly wrong, as well as 50 psi...to hit the numbers that I do, most people will run 200-300 more psi than I currently do..provided their reg isn't feeding the plenum well enough during the shot cycle. I would also have to double my plenum volume to be able to hit the 64 fpe again if I were to plug my reg so it cannot feed anything into my plenum during the shot cycleBelow, pictured on the left is a plenum that is fed very well during the shot cycle by the reservoir, on the right, one that is not...the closer to 1 cc per fpe the less noticeable this effect...but for very small plenums, this effect is quite dramatic. (1975 regulated, 19.5" barrel .225" porting (.23" valve that transitions into .225" barrel port) 53cc plenum 33.95gr jsb)
Quote from: PikeP on June 10, 2020, 05:49:58 PMIn my findings, the difference between a regulator with a very restrictive orifice that marginally feeds your plenum opposed to a larger orifice that feeds your plenum enough to act as a partial auxiliary plenum, is noteworthy, even more so as you increase caliber or power output. The smaller the plenum is relative to your power output, the more noteworthy. Even in my configuration, with 53 cc, my peak output is currently 64 fpe at sub 2k regulated only because my plenum is partially fed by my reservoir during the shot cycle..if I were to plug my regulators feed holes to where the air flow was negligible, I would likely have a power output of 59 fpe being sub 2k psi regulated...Having listened to Bob over the years, the gold standard of 1cc of plenum to one FPE of output, echos in my head. But have definitely gone down to 1/2cc per, with good results. In your case, it seems like all the work on the reg, only saved about 5cc's of plenum. Bumping the reg up 50psi would be the next option. Offhand, just doesn't seem worth the additional design/testing effort. We all have our areas we like to dig in on. Just for clarity. do you build your own regs, or modifying a production one? Some of the pictures you posted looked like Lanes, but haven't used that one.
In my findings, the difference between a regulator with a very restrictive orifice that marginally feeds your plenum opposed to a larger orifice that feeds your plenum enough to act as a partial auxiliary plenum, is noteworthy, even more so as you increase caliber or power output. The smaller the plenum is relative to your power output, the more noteworthy. Even in my configuration, with 53 cc, my peak output is currently 64 fpe at sub 2k regulated only because my plenum is partially fed by my reservoir during the shot cycle..if I were to plug my regulators feed holes to where the air flow was negligible, I would likely have a power output of 59 fpe being sub 2k psi regulated...
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