Impact with PP and External Plenum
- Thread starter Zeringue
- Start date
Yeah, Ken from SPAW says it give no extra benefit to have both. He knows WAY more about these guns than i do, but i still don’t understand how 2 upgrades that add efficiency and power to a platform, can’t help even more when you put them together? You’d think you’d see some small improvement even if it’s just minor?
Upvote 0
Law of diminishing returns. But, that said, there should be gains provided the volume increase is between 50-100%, anything below that is hardly noticeable once you're hovering around 1 cc per fpe...once you hit 1.5-2 cc per fpe however, there are very little to no gains to be had.
Upvote 0
I have to say it leaves me curious as well. I can see Ernest trying it on a Impact, but I just find it hard to believe he would run two plenums if it didn't find some benefit. I hope some of our in-house tech-tuners chime in and gives us some of their thoughts and maybe experience.
Eamon
Upvote 0
I literally gave you the most technical answer possible. It really depends on how much FPE you intend on putting out. A .177/.22 shooting pellets won't benefit nearly as much as a .25/.30 cal shooting heavier pellets or slugs..anything over 2 fpe per CC of plenum volume has diminishing returns. This is because during the shot cycle, your plenum pressure drops based on its volume and the volume you eject from it, but once the ratio of that is surpassed by meeting the 2 fpe/cc criteria, your pressure drop will be so low at the valve seat, that any increase is negligible...this graph shows how critical it is to be at least 1/4-1/2 fpe per cc, and 1 fpe per cc is a great middle ground, and 2 fpe per cc is close enough to peak to not consider going further...this scales with all calibers and power levels.
Upvote 0
I tried with them both with no extra gain
If anything i was loosing power
It was with the 30 cal
So i only have the pp on the gun now,because it is more ergonomic.
There something turbulent happining in the plenum
It is better that all the plenum air is in one cylinder.
If anything i was loosing power
It was with the 30 cal
So i only have the pp on the gun now,because it is more ergonomic.
There something turbulent happining in the plenum
It is better that all the plenum air is in one cylinder.
Upvote 0
I have installed both on Impacts and surely the two plenums i.e. PP and external plenum increases shot count and consistency way greater than only one.
As far as power is concerned there is a limit for it and to increase the power we need better air flow that includes additional modifications like heavy hammer weight, bigger transfer ports etc.
Regards,
Umair Bhaur
As far as power is concerned there is a limit for it and to increase the power we need better air flow that includes additional modifications like heavy hammer weight, bigger transfer ports etc.
Regards,
Umair Bhaur
Upvote 0
Thanks for the reply’s back. I don’t have an impact but I do want one. I though it was very interesting.
Upvote 0
@ Ackuric, I am sorry it looks like I was typing while you were answering. I did not see your reply till this morning. I shut down directly after hitting the submit button.
Eamon
Eamon
Upvote 0