Valveless Tuning
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Topic: Valveless Tuning (Read 4308 times))
rsterne
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Bob and Lloyd
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Re: Valveless Tuning
«
Reply #20 on:
December 13, 2015, 02:40:55 PM »
Extreme pressures would increase the power and efficiency of a PCP, but unfortunately it is not a linear trend once you go past about 3000 psi in terms of shot count.... In theory, if you had a regulator set to deliver 1500 psi to the valve, a gun with a reservoir at 4500 psi should deliver twice the shot count of one with a 3000 psi reservoir (based on Boyle's Law for Ideal Gasses).... and at 6000 psi it should have 3 times the shot count.... but air, Nitrogen, or Helium do not act in an ideal fashion.... Using air as an example, if it was an ideal gas a tank would hold 50% more molecules at 4500 psi than at 3000.... but in fact it only holds about 34% more.... At 6000 psi, instead of holding twice the number of molecules (100% increase), it only holds about 58% more.... This is because the molecules are so close together they are colliding with themselves more instead of just the walls of the container as the air gets "thicker" with increased pressure.... In reality, that gun regulated to 1500 psi would only get 89% more shots with a 4500 psi reservoir (instead of 100%).... and 158% more with a 6000 psi reservoir (instead of 200%).... At even higher storage pressures, the effect continues to get worse.... Then, as you mention, you have the safety, weight and/or cost of containing such high pressures....
Bob
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Coalmont, BC, Canada
🇺🇦
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since! 🇺🇦
Airsenal:
1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).
Bill G
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Re: Valveless Tuning
«
Reply #21 on:
December 13, 2015, 08:59:41 PM »
Quote from: rsterne on December 13, 2015, 01:46:18 AM
cc's per CI.... what is the 13.1 ?
Bob
Iirc it is to convert kpa/cc to psi. I think you helped me with that a long time ago.
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Nicholasville KY
Engineering is the art of modeling materials we don't wholly understand, into shapes we can't precisely analyze, so as to withstand forces we can't properly asses, in such a way that the public has no reason to suspect the extent of our ignorance.
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Valveless Tuning