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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: max115 on October 14, 2020, 09:27:03 PM

Title: FX Impact power plenum DIY
Post by: max115 on October 14, 2020, 09:27:03 PM
Here is a video I did on installing the power plenum on my FX Impact MK2.
Please do not follow my instruction to avoid damaging your gun. There are better instructional videos out there.
The plenum gives higher power and shot counts as advertised.

The work is still to be done to find the optimal setting with Reg pressure, hammer spring and ammunition.

enjoy.

https://www.youtube.com/watch?v=VM9_HV97zxQ (https://www.youtube.com/watch?v=VM9_HV97zxQ)
Title: Re: FX Impact power plenum DIY
Post by: triggertreat on October 15, 2020, 12:18:01 PM
Thanks Max!  I installed a PP kit a few months ago.  Initially I put the old valve spring in the new plenum and kept the rubber ball cap.  Some said I would get more power that way.  After shooting it that way for a while, I then put the full kit as designed in there.  Both methods work well but I do like the added valve control of the PP full kit, and have a little more power this way.

The air you hear is the large PP tank refilling after a shot.  I like it because if something changes I should be able to hear a difference.
Title: Re: FX Impact power plenum DIY
Post by: max115 on October 15, 2020, 08:02:31 PM
@triggertreat. Yes I agree. the hammer spring with the kit gives you the better range of velocity with the power wheel adjustment. I guess I will need to mod the valve or upgrade the slug kit for more power.
Title: Re: FX Impact power plenum DIY
Post by: triggertreat on October 16, 2020, 01:12:46 AM
@triggertreat. Yes I agree. the hammer spring with the kit gives you the better range of velocity with the power wheel adjustment. I guess I will need to mod the valve or upgrade the slug kit for more power.

I haven't taken mine to that next step yet for power.  There is a limit to the PP hammer system currently to knock the valve open.  A lower set point will help the hammer system a bit more to gain power, like from 150 bar down to 135-140 bar or thereabouts, or a lighter valve spring.  I'll probably wind up with the slug kit once I see them in stock.  I do already have the dual ports and modified probe, which did give me another 50 FPS.  I'm not sure what can be done to open up the new PP valve more.
Title: Re: FX Impact power plenum DIY
Post by: Glem Chally on October 16, 2020, 02:45:13 AM
The new valve stop system with the spring saps power, necessitating the slug power kit which the biggest power gain from that is the lighter spring.   

75fpe in .22 with a 700mm, using a big plenum (same size as fx PP), modified TP and probe, hammer weight, same size valve seat as PP, old spring inside the plenum and old rubber ball valve stop bumper, old hammer spring.  Stock valve size, valve house not touched.

*and been this way for a year

The valve adjuster can adjust the speed from in the 300s to over 1000 for example I simply dont see how anyone gets more adjustability or power with the new spring setup instead of rubber ball.  I've been wrong before but I have a friend with the identical setup as me the only change is the full PP kit vs the hybrid and his gun makes less power.  And the valve adjust knob has a much more narrow range of adjustment.   My opinion only, based on experience.
Title: Re: FX Impact power plenum DIY
Post by: triggertreat on October 16, 2020, 03:08:22 AM
The new valve stop system with the spring saps power, necessitating the slug power kit which the biggest power gain from that is the lighter spring.   

75fpe in .22 with a 700mm, using a big plenum (same size as fx PP), modified TP and probe, hammer weight, same size valve seat as PP, old spring inside the plenum and old rubber ball valve stop bumper, old hammer spring.  Stock valve size, valve house not touched.

*and been this way for a year

The valve adjuster can adjust the speed from in the 300s to over 1000 for example I simply dont see how anyone gets more adjustability or power with the new spring setup instead of rubber ball.  I've been wrong before but I have a friend with the identical setup as me the only change is the full PP kit vs the hybrid and his gun makes less power.  And the valve adjust knob has a much more narrow range of adjustment.   My opinion only, based on experience.


With the new valve spring you can lighten the valve tension by backing out the knob beyond 4 lines until it hits the stop.  It could be that I had the old hammer spring in my hybrid setup, plus I added in a spacer too when going full PP kit.  The ES is very stable either way.
Title: Re: FX Impact power plenum DIY
Post by: Glem Chally on October 16, 2020, 02:03:17 PM
The new valve stop system with the spring saps power, necessitating the slug power kit which the biggest power gain from that is the lighter spring.   

75fpe in .22 with a 700mm, using a big plenum (same size as fx PP), modified TP and probe, hammer weight, same size valve seat as PP, old spring inside the plenum and old rubber ball valve stop bumper, old hammer spring.  Stock valve size, valve house not touched.

*and been this way for a year

The valve adjuster can adjust the speed from in the 300s to over 1000 for example I simply dont see how anyone gets more adjustability or power with the new spring setup instead of rubber ball.  I've been wrong before but I have a friend with the identical setup as me the only change is the full PP kit vs the hybrid and his gun makes less power.  And the valve adjust knob has a much more narrow range of adjustment.   My opinion only, based on experience.


With the new valve spring you can lighten the valve tension by backing out the knob beyond 4 lines until it hits the stop.  It could be that I had the old hammer spring in my hybrid setup, plus I added in a spacer too when going full PP kit.  The ES is very stable either way.

Perfect!  Sounds like you got a good tune there Keith 👍