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Viewing 12 replies - 1 through 12 (of 12 total)
Hi,
By plenum I do mean the spacer, I wanted to increase the spacer as I was lowering the standard reg pressure.
It isn’t strictly required, but as the huma reg is considerably shorter than standard there is a chance that the reg may line up incorrectly under the cylinder bleed hole, I did not have this issue but it was very close so hence the spacer.
I asked Huub to turn me a longer spacer for my second Vulcan as I didn’t want to use circlips to get the volume I wanted.
The Gen 4 reg from Huma is the correct dimension to fit with the standard spacer.
So to not confuse the situation, the plenum volume is directly related to the reg pressure, standard plenum requires 120b reg, setting the reg lower requires a larger volume while a higher reg pressure with the standard plenum should theoretically provide better efficiency as you would technically need less volume.
For regulated guns one needs to maintain the reg/plenum/valve and hammer balance for a desired pellet weight and speed. I target shoot at 100 yards so I wanted a tight ES at a speed of about 870fps so after much testing the balance I needed for an ES of 7 was the previously mentioned settings.
The gun can do 920+ FPS in standard form, at my 1260m altitude I find that anything above 890 FPS causes spiralling, I needed to find the balance for 870fps, that was 115bar on the reg, but the shot count suffered due to loosing too much air per shot, hence plenum increase and valve tension tune.
Good luck, tuning is tedious but the results can be very gratifying if achieved!
Have the reg in my .22 Vulcan. Huma have two versions for the Vulcan, some have had issues with the v1 reg and the gen4 Vulcan, I personally didn’t…
Huub can make you a tester for any gun, I requested a larger plenum for my gun and he obliged, I don’t see why he wouldn’t be able to do a custom reg tester.
I have a reg tester for the Vulcan but live in South Africa so cant offer to loan it… Huub will set the reg for you, but the tester IMHO is imperative for fine tuning.
My current setup is as follows:
Reg: 115b
Plenum: 10 % increase achieved by using 3x number28 Circlips stacked, and by custom Huma plenum in second gun.
Valve tension: half turn clockwise from default
18.1 jsb
869 FPS
96 shots
Crazy accurate at 100yards
Great info. By plenum do you mean the spacer that sits between the regulator and the valve? Is Huma plenum longer than the stock plenum?
But from what I read and heard they can be in some brands be equal or better than the factory reg.
I’m thinking of getting one for my Lelya for a diferant reason.
Also if you plan to tune different brand guns in the future, I’d ask John about reg tester that can except adaptors for each kind you plan to tune. Not sure about the Vulcan with its larger OD and what size you need to ask the maker for the tester.
Edited:
John/Aerotulz55 make a universal tester you need to ask him about it.
http://www.talonairgun.com/forum/viewtopic.php?f=54&t=33861#p347488
I have a tester that I bought from Dman that I use for my EDgun, Cricket and Taipan with adaptor, but I haven’t seen him post here in a while.
– Greg
Many thanks for the advise, I have emailed John lets see what he says. Have emailed Jaime also a few days ago but he didnt reply
I can endorse the Huma, and Huub.
Have the reg in my .22 Vulcan. Huma have two versions for the Vulcan, some have had issues with the v1 reg and the gen4 Vulcan, I personally didn’t…
Huub can make you a tester for any gun, I requested a larger plenum for my gun and he obliged, I don’t see why he wouldn’t be able to do a custom reg tester.
I have a reg tester for the Vulcan but live in South Africa so cant offer to loan it… Huub will set the reg for you, but the tester IMHO is imperative for fine tuning.
My current setup is as follows:
Reg: 115b
Plenum: 10 % increase achieved by using 3x number28 Circlips stacked, and by custom Huma plenum in second gun.
Valve tension: half turn clockwise from default
18.1 jsb
869 FPS
96 shots
Crazy accurate at 100yards
IDK I haven’t tried out one yet.
But from what I read and heard they can be in some brands be equal or better than the factory reg.
I’m thinking of getting one for my Lelya for a diferant reason.
Also if you plan to tune different brand guns in the future, I’d ask John about reg tester that can except adaptors for each kind you plan to tune. Not sure about the Vulcan with its larger OD and what size you need to ask the maker for the tester.
Edited:
John/Aerotulz55 make a universal tester you need to ask him about it.
http://www.talonairgun.com/forum/viewtopic.php?f=54&t=33861#p347488
I have a tester that I bought from Dman that I use for my EDgun, Cricket and Taipan with adaptor, but I haven’t seen him post here in a while.
– Greg
Did you try Ernest or John ?
Ernest Rowe
matomaya@earthlink.net
John Hagan
hagantool@aol.com
OR
Buying a HUMA regulator might be a cheaper option, no reg tester needed to set.
https://www.huma-air.com/Airgun-Technology-Vulcan-pressure-regulator
~ Greg
Is Huma regulator as good as the original?
.
Did you try Ernest or John ?
Ernest Rowe
matomaya@earthlink.net
John Hagan
hagantool@aol.com
OR
Buying a HUMA regulator might be a cheaper option, no reg tester needed to set.
https://www.huma-air.com/Airgun-Technology-Vulcan-pressure-regulator
~ Greg
Thanks for the suggeation, I have checked from them but they only make testers for huma regulators
Mine is 4th gen .25
what mark is your Vulcan? if early model Mark 1 or 2 with the degasser port, then you can get away with a brass adapter and manometer.
Viewing 12 replies - 1 through 12 (of 12 total)
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By plenum I do mean the spacer, I wanted to increase the spacer as I was lowering the standard reg pressure.
It isn’t strictly required, but as the huma reg is considerably shorter than standard there is a chance that the reg may line up incorrectly under the cylinder bleed hole, I did not have this issue but it was very close so hence the spacer.
I asked Huub to turn me a longer spacer for my second Vulcan as I didn’t want to use circlips to get the volume I wanted.
The Gen 4 reg from Huma is the correct dimension to fit with the standard spacer.
So to not confuse the situation, the plenum volume is directly related to the reg pressure, standard plenum requires 120b reg, setting the reg lower requires a larger volume while a higher reg pressure with the standard plenum should theoretically provide better efficiency as you would technically need less volume.
For regulated guns one needs to maintain the reg/plenum/valve and hammer balance for a desired pellet weight and speed. I target shoot at 100 yards so I wanted a tight ES at a speed of about 870fps so after much testing the balance I needed for an ES of 7 was the previously mentioned settings.
The gun can do 920+ FPS in standard form, at my 1260m altitude I find that anything above 890 FPS causes spiralling, I needed to find the balance for 870fps, that was 115bar on the reg, but the shot count suffered due to loosing too much air per shot, hence plenum increase and valve tension tune.
Good luck, tuning is tedious but the results can be very gratifying if achieved!
Thanks for all the information. My Vulcan is a .25 and it shoots the jsb kings 25 grain pellets at around 900 fps. I have recently tried shooting jsb king heavy 34 grain pellets and the gun shoots these at 770 fps I was thinking of some way to shoot the 34 grain pellets at 870 fps. That’s why I was asking about the how you increased the size of plenum as that will enable my gun to shoot 34 grain pellets faster.