Tuning Doux Technologies Plenum Upgrade for Air Venturi Avenger

[SkeeterHawk]

Hello once again, Avenger Enthusiasts.

I finally got some trigger time on my Avenger with the new plenum installed from Doux Technologies and I must say that I am impressed with how it has improved the power output of this gun. I have determined that H&N Baracuda Match perform the best in this barrel out to at least 75 yards, so that is what I have been testing with. Before I could only get them up to 875FPS (21.14gr or 36FPE) and that was with the stock setting on the regulator (2900psi) and the hammer spring all the way in. It came turned in 5+ times, so there was only a small amount of adjustment available with the stock tune and 36FPE was all I could get. After installing the plenum, I started with the regulator at 1200PSI and worked it up to 2000PSI before I got the ultimate tune for the Baracudas. Now, I only have to adjust the hammer spring from 1 turn to two turns to go from 821FPS to 875FPS, and I can now go above that and get over 900FPS...if I ever wanted to. Now the cocking cycle is much softer and I am putting out more energy. I suspect that I could pretty easily get over 60FPE now if I wanted to, but I am good with being able to push the Baracuda over 900FPS.

Here is what my gun looks like from the side now...

Here is a close-up view of the plenum installed...

This is pretty exciting to be getting so much out of a "budget gun". I'm getting sub 1/2" groups at 50 yards now consistently even in moderate wind, so this baby is getting ready to compete! Woo hoo!!

 

[SkeeterHawk]

I thought that I would give you a reference on the volume of this plenum. In this video with Tyler Patner (at about 1:25:30)

https://www.youtube.com/watch?v=fYHnT42-lEw,

Tyler mentioned that the stock plenum on the Avenger was about 12CC. The Doux website states that the new plenum is 11.4CC, so this is basically double. It is now 23.4CC. On the Doux website, Ruben mentions that you can "stack" multiple plenum units to increase the volume. You may want to do that if you want to push 40gr slugs at 1000FPS, but for Diabolos, one plenum unit is plenty.



Anyway, I thought that I would answer this question before it came up. This isn't a 72CC "Power Plenum" from FX, but at 33% of the volume, it sure makes a difference.

Happy shooting!

 

[SkeeterHawk]

For your amusement, who doesn't like charts and graphs?, I am posting the charts of the power adjustments that I did today after installing the plenum. It is obvious that I turned the 1800PSI setting up too high as it is the same as the 1900, but you can't turn the regulator down on the Avenger, so I just ran with it.

I don't think that I will want to get over 900FPS with the wind in Utah, so I think that the 2000PSI tune that I stopped at will be where I keep it. I have a ton of adjustability at this setting, and the hammer is nice and relaxed when shooting at about 875FPS, and I believe that is about as fast as I will want to take these anyway.

So there you have it. Some lovely charts to look at. Eat your heart out, AEAC Steve!

 

[Ducman1952]

Upgrading airguns in general is fun and rewarding but, the end game is still a low-end pcp that costs as much as a mid to high-end pcp. If you want accuracy and performance at a reasonable price, AEA is a very good option.

 

[tbullard]

The plenum upgrade is $35 not sure that buts you in mid to high-end pcp range.

 

[SkeeterHawk]

Upgrading airguns in general is fun and rewarding but, the end game is still a low-end pcp that costs as much as a mid to high-end pcp. If you want accuracy and performance at a reasonable price, AEA is a very good option.

I addressed your question in this post. Let me know what you think.

 

[Ducman1952]

It’s not just the plenum. It’s the cf bottle, the adapter to bottle, stock mods, etc.

 

[wendell]

SkeeterHawk, those Avengers sure raises a lot of curiosities! I'm enjoying myself. I may do a 25 in the future.

View attachment IMG_0264 (1).JPG

 

[Fly]

Cool I must check this out. Out of all the pcps I have now my Avenger is my favorite. Thank you for your post.

Fly

 

[SkeeterHawk]

Nice looking Avenger, @wendell. It looks like the brother of mine. Is that a Doux bottle conversion kit or something else?

 

[wendell]

Your guess is correct Skeeter Hawk! Got it from air guns archery fun. It's a laser too!

 

[Ranchibi]

Wonderful mods on that Avenger! Looks totally different and with the OEM un-choked barrel, great slug shooters as well. Nice upgrades.

 

[SaphireFalls1995]

Hello once again, Avenger Enthusiasts.

I finally got some trigger time on my Avenger with the new plenum installed from Doux Technologies and I must say that I am impressed with how it has improved the power output of this gun. I have determined that H&N Baracuda Match perform the best in this barrel out to at least 75 yards, so that is what I have been testing with. Before I could only get them up to 875FPS (21.14gr or 36FPE) and that was with the stock setting on the regulator (2900psi) and the hammer spring all the way in. It came turned in 5+ times, so there was only a small amount of adjustment available with the stock tune and 36FPE was all I could get. After installing the plenum, I started with the regulator at 1200PSI and worked it up to 2000PSI before I got the ultimate tune for the Baracudas. Now, I only have to adjust the hammer spring from 1 turn to two turns to go from 821FPS to 875FPS, and I can now go above that and get over 900FPS...if I ever wanted to. Now the cocking cycle is much softer and I am putting out more energy. I suspect that I could pretty easily get over 60FPE now if I wanted to, but I am good with being able to push the Baracuda over 900FPS.

Here is what my gun looks like from the side now...

View attachment 210877

Here is a close-up view of the plenum installed...

View attachment 210886

This is pretty exciting to be getting so much out of a "budget gun". I'm getting sub 1/2" groups at 50 yards now consistently even in moderate wind, so this baby is getting ready to compete! Woo hoo!!

Hey nice gun! I was wondering do you need to modify your stock for the plenum upgrade? I have the wood stock version but should be similar.

 

[SkeeterHawk]

Hey nice gun!

Thanks!

I was wondering do you need to modify your stock for the plenum upgrade? I have the wood stock version but should be similar.

Yes, I had to cut out the plastic stock to allow for the total diameter of the "plenum cap" which contains the bleed screw. I don't know if this would be necessary on the wood stock, but I imagine so. The small hole for the bleed screw is a lot "neater" than the whole diameter for the cap.

I hope that this helps!

Happy shooting!

Jonathan

 

[McMadCow]

I got a 16.5cc plenum for my .25cal AVA from Reidy over at GTA. The power boost was really impressive. I had to change the way I tune it, but it was really nice to be able to dial back the reg pressure and hammer to still get the velocities I need for each projectile.

 

[paul67]

Hey nice gun! I was wondering do you need to modify your stock for the plenum upgrade? I have the wood stock version but should be similar.

I did it wasn’t a big deal I just used a dremel and it worked great. I have a 33 cc plenum I made on mine, big difference in power and consistency shot to shot.

 

[paul67]

My .25 Avenger with my new plenum. I love the way it looks.

 

[silvershooter589]

View attachment 314412
My .25 Avenger with my new plenum. I love the way it looks.

Whats the max power you're getting with that in the 25 ? Does it eliminate regulator creep?

 

[paul67]

I also have opened the transfer port to 7/32 and the same thing with the barrel port.

 

[paul67]

Whats the max power you're getting with that in the 25 ? Does it eliminate regulator creep?

I haven’t went for the max fpe yet but right now here’s what I got with the regulator set at only 2000 I think I had the hammer spring in 4 1/2 turns. I’m sure it will do 70 fpe at least. I haven’t opened the poppet valve seat yet, that’s the biggest power increase. My goal is to be able to push heavy stuff at its optimal speed.