HW/Weihrauch Hw90 .25 tuning transferport help

Thank you for OEM stroke dimension and mod, I tucked away safely as I have same model. Their are a series of these schrader valves in the racing world at different RANGES PSI/BAR
https://www.schmidtyracing.com/Schrader-Valve-Cores-p/n-ft-shr-c.htm
With HW90 OEM valve at 377PSI/26BAR, and Theoben's reported at 700PSI/48 BAR, seems like you might need a higher spec Schrader-Valve-Core to push 25+fpe? Seeing a Theoben .25 shooting 25fpe was how I found racing valves.
My unit is happy from 12 to 18FPE @ about 13/15 to 20BAR, so I'm a happy camper. But with slider weights fingered together, a valve running from 40 to 800PSI, reactive or stepped plenum chamber volume adjustability, Weihrauch would have a sweet upgrade and be front of the pack for self contained adjustable break barrels for the next 20 years or so. I think 10 to 30fpe range might be possible. Isolate the recoil ala Norica Omnia ZES or Diana 54 tech would push into bottom of adjustable PCPs.
 
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After fitting the new cup seal and drill the tp to 3.4mm power dropped to 205ms 20gr pellet. Even it have a 90mm stroke.

Looks like the tp size to big and lost its peak pr wave. The red aussie seal have a bit of slow burn damage on it.
Thats cause higher peak pr with 3mm tp.
Not sure what to do, fit new aussie seal and try again?
Tp back to 3.0mm?

The notek seal not preformd wel loose fit. Now oem seal tight fit seal lost 45fps. Oem seal have a very to tight fit
Been a patchute seal its even have more frition when fire it. Lost some piston speed whit it.
Maybe convert to O ring seals no risk on slow burn and low friction speeds up the piston speed
 
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TP Size
3mm - .118 OEM
3.2mm - .125 Increase FPS
3.3mm - .129 Better or Same??
3.4mm - .133 Decrease FPS

The only beef I have is if this is going to be Weihrauch magnum gun that cost over $800 US it need to produce over 30 PFE in .25 cal and the only way to get there is to increase piston stroke length - Like the Gamo Magnum .25, Hatsan 135 .25 and Benjamin XL 725 .25....Weihrauch Needs To Get With The Program. Weihrauch HW90 has not change since 1990's. We all know that Germany and England make best high quality airguns in the world. I own 2 HW85, TX200 and Daystate Huntmans 43FPE.
 
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Yes hw must pick up in the springer gun market.

Im emailed them long time ago.
To asked them to make a high power breakbarrel / underlever gun.
Based on theoben elimanator/ beeman crowmagnum.

Its have a 31.4mm piston and 100mm stroke length.
Tp is 4mm and lenght 6mm
At 65 bar rampr. Its does around 28fpe .22
And 30 fpe .25.
Still no answer, germany have a strikt power level 7.5j limit above ist firearm.

Even if they redisgn the hw90 and do:
30mm bore
110mm stroke
High pressure ram system like Theoben HE.
Light weight piston around 300 grams
Then its capable around 28fp
 
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I had a 20 cak 2000 RX1(Beeman Hw90). It was overcharged at the factory and quickly burned through the factory seal. When it was dieseling noticeable and IIRC it was making 25 FPE. When it wasn't 23 or maybe 24 fpe with 11.42 FTTs. I rebuilt the gun with fresh o rings and Vortek piston seal. I had apart a number of times chasing a wild extreme spread and accuracy issues and the Vortek seal stood up much better than factory seal and of course made more power for the same ram pressure. It did show some slight signs of heat damage in the form of a star pattern and transfer port. I dialed down the pressure to about IIRC 21/22 bar and the gun was much more pleasant and accurate to shoot. It made ~20 maybe 21 fpe with 11.42 ftts and 13.73 Exacts.

I had that gun apart so many times messing around with that inertia weight and oring lubes, I'm not sure what fixed it. It was a real pita when it was done it had a ES of 6 and it was a solid <2 MOA rifle at 50 yards. I never touched the TP.

I'm not sure you see the power you're looking for without stroking it. I'm not familiar with the 25 caliber version but I wonder if the accuracy might not be acceptable if you push the power limits of the platform.

Also that rifle might actually make more power in 22. Normally stepping up calibers increases spring piston efficiency except a couple Hw80 & R1 have reported power losses converting from 22 to 25 caliber. I believe that's because 22 doesn't exhaust the swept volume so quickly. It does have a 5mm shorter stroke though.

The real fly in the ointment with that platform is the how far the TP is offset. Weihrauch tried to help that with the star pattern channeling but its not really helpful other than burning neat patterns in seals.

I wish you luck and hope you find what you're looking for. It took forever to get it working right but my RX1 was a great 20 fpe 20 cal rifle when done. It'd make more power but it became unruly and tortured piston seals.

Best of luck
Ron
 
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Thank you for OEM stroke dimension and mod, I tucked away safely as I have same model. Their are a series of these schrader valves in the racing world at different RANGES PSI/BAR
https://www.schmidtyracing.com/Schrader-Valve-Cores-p/n-ft-shr-c.htm
With HW90 OEM valve at 377PSI/26BAR, and Theoben's reported at 700PSI/48 BAR, seems like you might need a higher spec Schrader-Valve-Core to push 25+fpe? Seeing a Theoben .25 shooting 25fpe was how I found racing valves.
My unit is happy from 12 to 18FPE @ about 13/15 to 20BAR, so I'm a happy camper. But with slider weights fingered together, a valve running from 40 to 800PSI, reactive or stepped plenum chamber volume adjustability, Weihrauch would have a sweet upgrade and be front of the pack for self contained adjustable break barrels for the next 20 years or so. I think 10 to 30fpe range might be possible. Isolate the recoil ala Norica Omnia ZES or Diana 54 tech would push into bottom of adjustable PCPs

I agree if Weihrauch redesign there HW90
Longer stroke like 120mm - 130mm like Artemis GR1600W
Lighter piston like Titanium
Better inertia valve and maybe lighter if that helps
Better piston seal and o-ring
Special military coating
Recoilless design like Diana 54
Easy achieve over 40FPE and up to 50FPE
No need for PCP