Tuning Notos tuning HELP

Hi - I did a few updates on my .177 Notos - And unfortunately they turned out not like expected...

Huben dream valve + plenum
0,36l bottle
peek valve

I also ported the whole system:
1 marked in red - I drilled the bore up to 4mm (I did not touch any thread)
40 marked in blue - I drilled the bore up to 4mm
42 marked in green - I milled the bore up to 6mm (diagonal) - With the help of a 3D printed guide
Barel marked in red - I drilled the bore up to 4mm

I polished and cleaned everything...
After I reassembled everything with silicon oil and some new o-rings I get the following results:

Regulator set to about 2200 psi
Hammer spring screw fully turned in - so heaviest load
about 700 fps
about 11 fpe

I already played around with the PSI and the hammer spring screw but the above results were finally the best I could get...
I played also a little bit around with some heavier pellets and slugs - But this was worse...
Can someone please help me how you reached 850fps+ and more fpe? I expected more with all the porting and tuning.

If I do a shoot test with the JSB Hades (0,670g / 10,34 gr) at about 30yrd it groups perfectly - So I'm very happy with that - Only the power is not satisfying.


Thanks to all the Notos threads here with the good information and all the help that you already provided!

Notos-Drawing.jpg
 

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Hi - I did a few updates on my .177 Notos - And unfortunately they turned out not like expected...

Huben dream valve + plenum
0,36l bottle
peek valve

I also ported the whole system:
1 marked in red - I drilled the bore up to 4mm (I did not touch any thread)
40 marked in blue - I drilled the bore up to 4mm
42 marked in green - I milled the bore up to 6mm (diagonal) - With the help of a 3D printed guide
Barel marked in red - I drilled the bore up to 4mm

I polished and cleaned everything...
After I reassembled everything with silicon oil and some new o-rings I get the following results:

Regulator set to about 2200 psi
Hammer spring screw fully turned in - so heaviest load
about 700 fps
about 11 fpe

I already played around with the PSI and the hammer spring screw but the above results were finally the best I could get...
I played also a little bit around with some heavier pellets and slugs - But this was worse...
Can someone please help me how you reached 850fps+ and more fpe? I expected more with all the porting and tuning.

If I do a shoot test with the JSB Hades (0,670g / 10,34 gr) at about 30yrd it groups perfectly - So I'm very happy with that - Only the power is not satisfying.


Thanks to all the Notos threads here with the good information and all the help that you already provided!

View attachment 587793
It sounds like you drilled 1 place too many, I thought you only had to port the barrel, the plate behind the plenum and the block?

Also could it be you simply have too much reg and not enough hammer/hammer spring?
 
It sounds like you drilled 1 place too many, I thought you only had to port the barrel, the plate behind the plenum and the block?

Also could it be you simply have too much reg and not enough hammer/hammer spring?
Exactly my thoughts. 2200 sounds like a recipe for partial valve lock and low valve dwell.

Be prepared to explore heavier hammers or more powerful hammer springs. Extra mass may be all you need to extend valve open time. If that's not feasible, a more powerful spring will at least launch the hammer you have a bit harder.

I'm a fan of tuning with stock springs and more hammer mass when possible just for the chot cycle experience smoothness. You can't always avoid stronger springs tho.
 
For just some comparison and food for thought. I have a different gun, with a longer barrel.... But 2175 psi allows me to shoot 34 grain slugs at just under 1000fps. The barrel length difference allows me to use the longer valve open time.

Now that I ponder a little more, maybe just spring would suit you because you don't have a ton of barrel and a short valve event would lend itself to air efficiency.
 
Hi - I did a few updates on my .177 Notos - And unfortunately they turned out not like expected...

Huben dream valve + plenum
0,36l bottle
peek valve

I also ported the whole system:
1 marked in red - I drilled the bore up to 4mm (I did not touch any thread)
40 marked in blue - I drilled the bore up to 4mm
42 marked in green - I milled the bore up to 6mm (diagonal) - With the help of a 3D printed guide
Barel marked in red - I drilled the bore up to 4mm

I polished and cleaned everything...
After I reassembled everything with silicon oil and some new o-rings I get the following results:

Regulator set to about 2200 psi
Hammer spring screw fully turned in - so heaviest load
about 700 fps
about 11 fpe

I already played around with the PSI and the hammer spring screw but the above results were finally the best I could get...
I played also a little bit around with some heavier pellets and slugs - But this was worse...
Can someone please help me how you reached 850fps+ and more fpe? I expected more with all the porting and tuning.

If I do a shoot test with the JSB Hades (0,670g / 10,34 gr) at about 30yrd it groups perfectly - So I'm very happy with that - Only the power is not satisfying.


Thanks to all the Notos threads here with the good information and all the help that you already provided!

View attachment 587793
Might not be a fair comparison because mine is a .22 but I have a fx liner/ 500mm barrel kit, upgraded brass valve to 4mm and hammer weight I'm shooting 16grains at around 830 to 850 and 14.3 at around 903. Get a hammer weight it helps alot, I got mine from c88, keep in mine this was with oem tank setup but with plenum and plenum extention also from c88.
Also I have not ported the air tank connector or the the one on the chassis and have not messed with regulator.
Valve: https://c88-air.com/products/umarex-notos-brass-valve?_pos=1&_sid=1a2f498a4&_ss=r

Hammer weight https://c88-air.com/products/umarex-notos-brass-hammer-weight?_pos=4&_sid=1a2f498a4&_ss=r
 
Might not be a fair comparison because mine is a .22 but I have a fx liner/ 500mm barrel kit, upgraded brass valve to 4mm and hammer weight I'm shooting 16grains at around 830 to 850 and 14.3 at around 903. Get a hammer weight it helps alot, I got mine from c88, keep in mine this was with oem tank setup but with plenum and plenum extention also from c88.
Also I have not ported the air tank connector or the the one on the chassis and have not messed with regulator.
Valve: https://c88-air.com/products/umarex-notos-brass-valve?_pos=1&_sid=1a2f498a4&_ss=r

Hammer weight https://c88-air.com/products/umarex-notos-brass-hammer-weight?_pos=4&_sid=1a2f498a4&_ss=r
I didn't even know there was a hammerweight
 
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Yeah, the notos has like everything to customize, i love it. Im getting like 33 to 37fpe on it so its nothing like it came out of the box
Nice! I have other powerful air rifles, i'm getting another notos for low power and higher shot count. But I am definitely adding the peek low force valve and the cocking lever
 
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Nice! I have other powerful air rifles, i'm getting another notos for low power and higher shot count. But I am definitely adding the peek low force valve and the cocking lever
I got the pump action cooking mechanism from buckrail if you are hunting it makes it really comfortable and fast, if you are bench shooting not so much, around 70dllrs and comes with everything you need, cooking lever and pump action mechanism.


Also on ebay if you want to be silly there's this guy that sells the p90 chasis for the notos, looks silly but I like it, I'm looking to buy another notos just to get that chasis

Screenshot_20250822_081311_eBay.jpg
 
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I got the pump action cooking mechanism from buckrail if you are hunting it makes it really comfortable and fast, if you are bench shooting not so much, around 70dllrs and comes with everything you need, cooking lever and pump action mechanism.


Also on ebay if you want to be silly there's this guy that sells the p90 chasis for the notos, looks silly but I like it, I'm looking to buy another notos just to get that chasis

View attachment 587969
I did notice that from his site, it is temporarily out of stock though. I also saw that stock and it's on sale for the low price of $1,000 🫠
 
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It sounds like you drilled 1 place too many, I thought you only had to port the barrel, the plate behind the plenum and the block?

Also could it be you simply have too much reg and not enough hammer/hammer spring?
I don't think so because this should be the "configuration" that others run also...

I can think of 2 possible things, either you are getting Valve lock and need to turn down the regulator or the barrel is installed 180° out meaning port is on top not bottom, I did this once.
make sure this is not the case, then get back to us,
Thanks for the hint - Checked the barrel position and it's correct!


@KatoKevin454 / @6gun / @lopezvega95
Thanks for the help and links! I will first try it with much lower pressure and increase it slowly until I reach the top of fps with the current setup.
I will try to find a way to get the weight and valve (they are not shipping to my location).

Yeah, the notos has like everything to customize, i love it. Im getting like 33 to 37fpe on it so its nothing like it came out of the box
Can you say your detailed configuration and mods you did?
 
I don't think so because this should be the "configuration" that others run also...


Thanks for the hint - Checked the barrel position and it's correct!


@KatoKevin454 / @6gun / @lopezvega95
Thanks for the help and links! I will first try it with much lower pressure and increase it slowly until I reach the top of fps with the current setup.
I will try to find a way to get the weight and valve (they are not shipping to my location).


Can you say your detailed configuration and mods you did?
I replaced stock barrel to FX STX Superior Liner 500mm -utah airguns
Barrel kit -c88

Brass valve 4mm and hammer weight 4mm/5grams -c88

Plenum and plenum extention -c88

Cnc made suppressor

Pump lever action mechanism -buckrail

1/2 picatiny riser for scope

15 turns on hammer spring from thread 1

I have not messed with regulator and I'm currently in the process of extending my stock notos airtank to 2 oem notos tanks but I'm having feeding issues.
Air Tank to air tank adapter -88

20250822_190228.jpg
 
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