Umarex "Umarex Notos Update HUGE power Upgrade!" Or is it?
- Thread starter Firewalker
- Start date
So Firewalker cut and crowned an FX liner for my 380mm barrel kit from C88machining. I also ordered c88's plenum and plenum extension. I already had a gauge block from Wes @ Airgunarcheryfun.ca and decided to keep it on there.
Man oh man, it was close to not fitting but it fits.
Moderator is close to the airtube but doesn't touch, about 1mm of clearance.
Overall length is now 36-1/2" as I use it with the stock extended and a Donny FL Tanto on the end. And it still feels light!
It weighs, as you see it, 5lbs 1oz according to my kitchen scale. Scoping it will put it over 6lbs but will be worth it.
Here is the kit laid out as I got it from Firewalker after he cut the barrel and assembled the kit for testing.
He and c88machining both did a great packing job on the parts.
Just did some testing and it looks like I gained 50 fps while still having 4mags before I drop off the reg. Nice!
CPHP were doing 825fps for 21.6 FPE and are now going 875fps for 24.32 FPE. H&N Slug HP .218 were going 675fps before and now are going 730fps.
Without a re-zero while doing chronograph testing, I was hitting my spinner about an inch up and to the left.
Finding accuracy should be a breeze.
Famous last words, lol.
Man oh man, it was close to not fitting but it fits.
Moderator is close to the airtube but doesn't touch, about 1mm of clearance.
Overall length is now 36-1/2" as I use it with the stock extended and a Donny FL Tanto on the end. And it still feels light!
It weighs, as you see it, 5lbs 1oz according to my kitchen scale. Scoping it will put it over 6lbs but will be worth it.
Here is the kit laid out as I got it from Firewalker after he cut the barrel and assembled the kit for testing.
He and c88machining both did a great packing job on the parts.
Just did some testing and it looks like I gained 50 fps while still having 4mags before I drop off the reg. Nice!
CPHP were doing 825fps for 21.6 FPE and are now going 875fps for 24.32 FPE. H&N Slug HP .218 were going 675fps before and now are going 730fps.
Without a re-zero while doing chronograph testing, I was hitting my spinner about an inch up and to the left.
Finding accuracy should be a breeze.
Famous last words, lol.
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Oh so my 10cc estimate was real close and relevant. Lots of more power available there with a larger volume budget. Great work on pushing yours to its limits.
-Matt
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I’ve got a plenum ready to be threaded if usps does their part tomorrow. I suppose we’ll see. Appreciate the analysis 
. Hopefully have some numbers soon. I have a feeling this thing's going to need a bigger boat….. I mean tank, lol.
Dave
. Hopefully have some numbers soon. I have a feeling this thing's going to need a bigger boat….. I mean tank, lol. Dave
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I’ve got a plenum ready to be threaded if usps does their part tomorrow. I suppose we’ll see. Appreciate the analysis
Dave
Look forward to your results so I can do some comparative analysis with my formulas/spreadsheet. Hope you go big on that new plenum! Lol.
-Matt
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I'm
Running a .48L bottle on the big gun!
I’ve got a plenum ready to be threaded if usps does their part tomorrow. I suppose we’ll see. Appreciate the analysis
Dave
Running a .48L bottle on the big gun!
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The usps came through but the die cut an undersized thread so I ended up single pointing it on the mini lathe. The tap was fine though. I made the plenum from an inline filter housing. It brought my volume up to 21cc total.
My reg set point kept coming up as the reg was breaking in (I assume), so I had to adjust it down a bit. Pressure before each shot is listed. The original 2600 test was around 2620, now it’s a little lower, hopefully the reg will settle.
It has quite a bark with the short barrel.
Obviously the faster shots are with 14.3gr and the slower are 25.4
Dave
My reg set point kept coming up as the reg was breaking in (I assume), so I had to adjust it down a bit. Pressure before each shot is listed. The original 2600 test was around 2620, now it’s a little lower, hopefully the reg will settle.
It has quite a bark with the short barrel.
Obviously the faster shots are with 14.3gr and the slower are 25.4
Dave
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Nice, I predicted 40 fpe or around 838 FPS with 25.4's and a 20cc plenum and you hit 39 and 836 FPS. Pretty dang cool. Nice 4-5 FPE gain from the plenum jump.
Seeing a notos put out 40 fpe in .22 is something else, I bet it barks!
-Matt
Seeing a notos put out 40 fpe in .22 is something else, I bet it barks!
-Matt
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Running the reg that ‘high’ is just a random number to experiment with. 2600 isn’t that high to me. If you consider an unregulated gun, the initial point is a lot higher. To make power with short barrels, higher pressure is a way to do that.
This gun is only an experiment and will undoubtedly be tuned way back. A lighter hammer will be tested at some point as well. Something to do inside during this rainy season here.
Dave
This gun is only an experiment and will undoubtedly be tuned way back. A lighter hammer will be tested at some point as well. Something to do inside during this rainy season here.
Dave
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And yes, stock barrel with added plenum, with my other mods I mentioned earlier in thread.
The set point change may very well be from the higher setting. Keep in mind though, I’m probably one of the few who have actually measured the output of the factory regulator and I’m doing it with a digital gauge which is overly accurate for most applications. If it’s cool outside, just holding the plenum in your hand will warm it up and make a decent pressure jump.
Dave
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Nice! I just went back and looked at your other mods.
I was trying to up power while maintaining shot count but I didn't get near the power increase you have for obvious reasons.
Looks like it's time to do some porting and see if I can find the happy medium of fps and shot count....
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I'm running 2500 psi on my 700mm Notos. I'll go higher in the future but I need a tap and a good reamer first.
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Nice! I just went back and looked at your other mods.
I was trying to up power while maintaining shot count but I didn't get near the power increase you have for obvious reasons.
Looks like it's time to do some porting and see if I can find the happy medium of fps and shot count....
The good news is that you can up the power by porting.
The bad news is that once you port it, your shot count will always be lower.
Part of the Umarex engineering was its outstanding balance of 750 fps with a good shot count for such a small tube. Once you open it up, you create a larger plenum within the receiver itself and that air will always leave the gun when you pull the trigger.
Back to the good news: Hammer weight, hammer spring and preload spring are tuneable! You may find as did I that using a softer hammer spring gives you more velocity with a the gun ported.
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I’m looking at the real estate available between the valve and barrel and I think there is plenty of room to put a choke in there. I’m not the most knowledgeable on this type of tuning but in conversations with Matt, it helps with es when going lower on a tune. Maybe he can talk me into or out of a tp adjuster. Keep in mind, this is only experimental fun.
Dave
Dave
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Yes, from the side of the receiver block you can do a TP choke but you'll need perfect alignment and a good mill.
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