Power Plenum ~ Taipan Veteran

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I

I put a plenum extension on my .25 cal. with the expectations of gaining power but did not gain any power. If you are expecting a power gain don't waste your money. Tried contacting Ernest about the failure to increase power but no response. The reason I bought the plenum extension is because of his claim it would give a 30-45 FPS increase with out any increase to regulator pressure. Was trying for more power to test some slugs. Max velocity before plenum extension was 920 FPS. Max velocity after plenum extension is 920 FPS. Regulator is set at 145 Bar.
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That’s strange but I did port the firing-valve a bit too, nothing major though. I was maxing at 940 fps with 33.95 grainers when my reg was at 142 bar. 


Did you adjust your hammer spring and find your max after the plenum install?



I have ported my valve some and polished the transfer port. Yes I did adjust my hammer sping to max after install. My max velocity is when hammer spring is at max just before the gun won't cock.
Click to expand...


 
Upvote 0
I

I put a plenum extension on my .25 cal. with the expectations of gaining power but did not gain any power. If you are expecting a power gain don't waste your money. Tried contacting Ernest about the failure to increase power but no response. The reason I bought the plenum extension is because of his claim it would give a 30-45 FPS increase with out any increase to regulator pressure. Was trying for more power to test some slugs. Max velocity before plenum extension was 920 FPS. Max velocity after plenum extension is 920 FPS. Regulator is set at 145 Bar.
Click to expand...

That’s strange but I did port the firing-valve a bit too, nothing major though. I was maxing at 940 fps with 33.95 grainers when my reg was at 142 bar. 


Did you adjust your hammer spring and find your max after the plenum install?



I have ported my valve some and polished the transfer port. Yes I did adjust my hammer sping to max after install. My max velocity is when hammer spring is at max just before the gun won't cock.
Click to expand...

Click to expand...

Sounds like you need a stronger hammer spring then. What version do you have Standard or Long? I assume a Standard. If so, with the shorter barrel, you need a bit more help to get power up. 
 
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Sounds like you are reaching the max that your current hammer weight/spring combination can do with the current reg pressure. You can reduce your reg pressure about 10 to 15 bar and try again. Or, you can increase your spring tension, or increase your hammer weight. You should be able to increase your pellet speed to the point where it levels out and then starts to decrease. If that isn't possible, then you are in the situation I just described above. I've installed two plenums in .22 Cricket mini Carbines, and three plenums in .25 Cricket bull pups, and each time the speed went up 30 to 40 FPS without any other changes whatsoever. I've never done it on a Taipan, but I've owned a .22 Mutant and .25 Veteran Shorty.
 
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Interesting. I have my .25 long tuned for King Heavies at 904 ave fps, no add ons other than HST tool, and I am getting a solid 37 shots before I drop off the reg.
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What are you filling to? I’m just filling to 250 bar. Also, I can easily squeeze another 4-5 more shots that are still tight but are losing a tad of velocity. These shots would be same POI on paper to 40 yards. When I say 42 regulated shots, I mean exactly that; the pressure in the tube is above the reg’s set point.

On the other end of the spectrum, when first installed the power plenum, I scrubbed off only 8 bar from the 150 bar factory setting. The gun was maxing at 940 fps at 142 bar. Can your gun do that as well? If so, you need to verify your chrony or you may have a Taipan alien
1f47d.svg
 

Regardless, I’m just sharing what I’ve experienced. I don’t really have an ulterior motive here. I am certainly not open for business to tune the public’s PCPs. I’m much too busy for that and it would probably become work/ a killjoy. Good day and latter on guys. 

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Filling to 250 bar. Tuned so ave FPS is 904 fps, 15 spread, SD 4.2, with the 33 gr heavies. FX chrony. 

I get a solid 37 shots in that range. #38 dips into 890s, then 880s, 870s, and so on. 

I'll run it again and see what I end up with. 


 
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That's awesome!!!

Love the coffee lam stock really looks nice...

Power plenum? Do you contact Ernest directly? I'd like to try that out on my .22 long. I'm getting about 30 shots maxed out right now shooting slugs...sounds like I could really step that count up! And by looks will have to change out the LDC...
1575939694_5699038615deeee6e867167.54182505_20191208_134129.jpg


James from Michigan
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Not trying to hijack the post, but where did you get this stock and are stocks for other guns available from this maker?
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I believe a video pops up on my YouTube page for this stock once in a while. I'm pretty sure it's a Michal Osyda stock and I'm pretty sure the YouTube channel belongs to a regular poster on AGN.

I just checked and it wasn't there. Will post again if it pops up or I otherwise find it.
 
Upvote 0
Sounds like you are reaching the max that your current hammer weight/spring combination can do with the current reg pressure. You can reduce your reg pressure about 10 to 15 bar and try again. Or, you can increase your spring tension, or increase your hammer weight. You should be able to increase your pellet speed to the point where it levels out and then starts to decrease. If that isn't possible, then you are in the situation I just described above. I've installed two plenums in .22 Cricket mini Carbines, and three plenums in .25 Cricket bull pups, and each time the speed went up 30 to 40 FPS without any other changes whatsoever. I've never done it on a Taipan, but I've owned a .22 Mutant and .25 Veteran Shorty.
Click to expand...

I

I put a plenum extension on my .25 cal. with the expectations of gaining power but did not gain any power. If you are expecting a power gain don't waste your money. Tried contacting Ernest about the failure to increase power but no response. The reason I bought the plenum extension is because of his claim it would give a 30-45 FPS increase with out any increase to regulator pressure. Was trying for more power to test some slugs. Max velocity before plenum extension was 920 FPS. Max velocity after plenum extension is 920 FPS. Regulator is set at 145 Bar.
Click to expand...

That’s strange but I did port the firing-valve a bit too, nothing major though. I was maxing at 940 fps with 33.95 grainers when my reg was at 142 bar. 


Did you adjust your hammer spring and find your max after the plenum install?



I have ported my valve some and polished the transfer port. Yes I did adjust my hammer sping to max after install. My max velocity is when hammer spring is at max just before the gun won't cock.
Click to expand...

Click to expand...

Sounds like you need a stronger hammer spring then. What version do you have Standard or Long? I assume a Standard. If so, with the shorter barrel, you need a bit more help to get power up.
Click to expand...





Mine is the Long version.

Sounds like the power plenum is not a plug and play power upgrade like Ernest said it is. His words were 30-45 FPS without any other modification's

If it is a weak hammer spring then it is a factory defect. But since I have had the gun apart there goes any warranty replacement parts. Does anybody have stronger hammer springs that will fit the Veteran Long .25 cal.? .
 
Upvote 0
Sounds like you are reaching the max that your current hammer weight/spring combination can do with the current reg pressure. You can reduce your reg pressure about 10 to 15 bar and try again. Or, you can increase your spring tension, or increase your hammer weight. You should be able to increase your pellet speed to the point where it levels out and then starts to decrease. If that isn't possible, then you are in the situation I just described above. I've installed two plenums in .22 Cricket mini Carbines, and three plenums in .25 Cricket bull pups, and each time the speed went up 30 to 40 FPS without any other changes whatsoever. I've never done it on a Taipan, but I've owned a .22 Mutant and .25 Veteran Shorty.
Click to expand...

I

I put a plenum extension on my .25 cal. with the expectations of gaining power but did not gain any power. If you are expecting a power gain don't waste your money. Tried contacting Ernest about the failure to increase power but no response. The reason I bought the plenum extension is because of his claim it would give a 30-45 FPS increase with out any increase to regulator pressure. Was trying for more power to test some slugs. Max velocity before plenum extension was 920 FPS. Max velocity after plenum extension is 920 FPS. Regulator is set at 145 Bar.
Click to expand...

That’s strange but I did port the firing-valve a bit too, nothing major though. I was maxing at 940 fps with 33.95 grainers when my reg was at 142 bar. 


Did you adjust your hammer spring and find your max after the plenum install?



I have ported my valve some and polished the transfer port. Yes I did adjust my hammer sping to max after install. My max velocity is when hammer spring is at max just before the gun won't cock.
Click to expand...

Click to expand...

Sounds like you need a stronger hammer spring then. What version do you have Standard or Long? I assume a Standard. If so, with the shorter barrel, you need a bit more help to get power up.
Click to expand...





Mine is the Long version.

Sounds like the power plenum is not a plug and play power upgrade like Ernest said it is. His words were 30-45 FPS without any other modification's

If it is a weak hammer spring then it is a factory defect. But since I have had the gun apart there goes any warranty replacement parts. Does anybody have stronger hammer springs that will fit the Veteran Long .25 cal.? .
Click to expand...

I have a few. PM me @mr.grimm
 
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Please share the shot string if you will @Pickzilla.
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Here's the one I just shot. Started to drop on shot #38. 

1576116810_5560259075df1a24a115e02.81557100_A19604C6-D083-440B-8C6B-0E060427FBD7.png
Click to expand...

Looks pretty good. Hard to tell without seeing the whole string. It’s a bit of a large ES. I like my ES to be no larger than 15 fps and 10 or less is really desirable. 3-4 SD is another target that I like to get to. Like said though, the gun will shoot 4, 5, 6 shots while off reg that will remain tight. Thank you for sharing. 
 
Upvote 0
Please share the shot string if you will @Pickzilla.
Click to expand...

Here's the one I just shot. Started to drop on shot #38. 

1576116810_5560259075df1a24a115e02.81557100_A19604C6-D083-440B-8C6B-0E060427FBD7.png
Click to expand...

Looks pretty good. Hard to tell without seeing the whole string. It’s a bit of a large ES. I like my ES to be no larger than 15 fps and 10 or less is really desirable. 3-4 SD is another target that I like to get to. Like said though, the gun will shoot 4, 5, 6 shots while off reg that will remain tight. Thank you for sharing.
Click to expand...

Yah, I wasn't thrilled with that ES. Dunno what is contributing to that... any ideas? The gun is super accurate with the King heavies... still gotta run the MK2s. I ordered the plenum, but just realized it moves the whole tube forward, and might not fit with the Sumo... ughhhh. Can't wait to slap the Athlon Ares ETR on it and go long. Stupid Winter.... 
 
Upvote 0
I like to find the plateau of a given reg set point. I do this by dialing in more HST while shooting over the chrony. 1/2 turn increment as large jumps in fps are happening and as the speed increase begin slowing I move to 1/4 turn increments. Once the plateau is found, you will recognize it when the speed doesn’t increase with several 1/4 turn increases and or will actually drop. The Taipan factory HS isn’t quite strong enough to show you where the plateau is. This is to say, the speed continues to increase until you cannot cock the gun. To find the plateau on Taipan Vets, I use a slightly stronger HS. 

Once the plateau is found, I drop the fps with the HST down from the plateau anywhere from 10 to 25 fps depending on how the gun performs. I’ve found that some like a 10 fps differential and others prefer 25 fps. It takes some chrony work to find the sweet spot of a given PCP. 


You are correct in thinking the Sumo will not work after you have the plenum installed. I am using a Koi which works well. 
 
Upvote 0
Mr. Wall got great info. I should have stated that speed or performance will very with the plenum / tube extension. I used a longer lighter hammer spring and modified the HSTA added 2 delrin bushing on the spring to reduce the spring twang, installed a lighter valve spring, angle porting aft of VS, enlarged the double TP. If I wanted 1000fps + with 34gn I install the FX 700mm STX slug barrel. You can double stack the tube extension!


will refund if you are not satisfied with the plenum as I did with phillip even though he didn’t ask.



https://www.instagram.com/p/B5B40qvBrsc/?igshid=84klqxcbmd9n

https://www.instagram.com/p/B5DJYv4heOA/?igshid=1ctm27aa0q7ha

https://www.instagram.com/p/B4QAMP8h2vG/?igshid=rackbz8capnn

https://www.instagram.com/p/B3Zwf6xBrOV/?igshid=k6g544qk82hp

https://www.instagram.com/p/B3ZtoN5h24_/?igshid=178jlb25dnqnh
 
Upvote 0
Mr. Wall got great info. I should have stated that speed or performance will very with the plenum / tube extension. I used a longer lighter hammer spring and modified the HSTA added 2 delrin bushing on the spring to reduce the spring twang, installed a lighter valve spring, angle porting aft of VS, enlarged the double TP. If I wanted 1000fps + with 34gn I install the FX 700mm STX slug barrel. You can double stack the tube extension!


will refund if you are not satisfied with the plenum as I did with phillip even though he didn’t ask.



https://www.instagram.com/p/B5B40qvBrsc/?igshid=84klqxcbmd9n

https://www.instagram.com/p/B5DJYv4heOA/?igshid=1ctm27aa0q7ha

https://www.instagram.com/p/B4QAMP8h2vG/?igshid=rackbz8capnn

https://www.instagram.com/p/B3Zwf6xBrOV/?igshid=k6g544qk82hp

https://www.instagram.com/p/B3ZtoN5h24_/?igshid=178jlb25dnqnh
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Thank you for chiming in E. Nothing with PCPs is plug and play, lol. My motto is plug, tune, set and play. I find what it likes and enjoy. I don't keep tinkering once I have the happy place found. 

I may want to install a STX barrel on a Vet one day 👊
 
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Thank you for the refund Ernest. But I returned the funds to you. Sounds like I have a spring issue. Mr. Wall is sending me a different hammer spring to try. I will also consider your suggestion about the valve return spring. What I meant by plug and play was I thought all I would have to do is adjust my hammer spring after installing the plenum extension to see a power increase. I owe you an apology Ernest. I apologize for saying your product was a waste of money without doing more trouble shooting on my gun.

All this back and forth and my gun probably wont even shoot slugs worth a crap and I will have to go back to my JSBs 34g @ 860 FPS.

Thank you to all that have given useful and constructive advice and suggestions. Phillip
 
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Mr. Wall got great info. I should have stated that speed or performance will very with the plenum / tube extension. I used a longer lighter hammer spring and modified the HSTA added 2 delrin bushing on the spring to reduce the spring twang, installed a lighter valve spring, angle porting aft of VS, enlarged the double TP. If I wanted 1000fps + with 34gn I install the FX 700mm STX slug barrel. You can double stack the tube extension!


will refund if you are not satisfied with the plenum as I did with phillip even though he didn’t ask.



https://www.instagram.com/p/B5B40qvBrsc/?igshid=84klqxcbmd9n

https://www.instagram.com/p/B5DJYv4heOA/?igshid=1ctm27aa0q7ha

https://www.instagram.com/p/B4QAMP8h2vG/?igshid=rackbz8capnn

https://www.instagram.com/p/B3Zwf6xBrOV/?igshid=k6g544qk82hp

https://www.instagram.com/p/B3ZtoN5h24_/?igshid=178jlb25dnqnh
Click to expand...

That's some pretty epic work there Ernest! 

I would ask how you managed to get an STX liner on your Long, but I suppose it's pretty involved... Maybe you'll post a few vids on your mods. I would love to get this baby up and firing heavy slugs at 1000 fps.

@zx10wall - Thank you for taking the time to share that advice. Think I should upgrade the spring?


 
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