What’s the most power possible from an Impact?

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I thought the impact x was supposed to be all the same with th exception of the pellet probe and barrel? So you’re telling me the valve seat is different between the .177/22/25 and the 30?
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I'm sure they all use the same valve and seat with maybe the 12fpe being different. They probably did it partly as a convenience thing when swapping caliber, having to change the valvepin and seat with calibers would both be a pain in the ass and cost more. Its obviously not in FX's agenda to make the most powerful gun in every caliber rather one platform that you can swap parts around relatively quickly and change calibers.

That's why there's so many other tuning parameters on Crown and Impact to use to fine tune it, is the most efficient and the best for big power? No, was that their intent? Probably not.
 
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If thats correct then that is correct, I was mistaken and mislead by assuming their valve seats were all the same...if thats the case I apologize...theres no way they are only making that much power @ 92% bore porting though...something doesn't add up and is restricting airflow?

The valve seat/throat to flow that much would need to be 8mm with a 3mm valve stem, and the bolt probe's area would have to be equal to 2.54 mm in diameter of a circle...if that criteria is currently met right out of the box, then I retract a lot of what I said in regards to fx's .30 cals....but if the above is NOT true then what I said before basically stands, because the above configuration should yield roughly 150 fpe no questions asked at 150-155 bar..



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The OEM valve seat measures 5.56mm but I'm using a 5.8mm one. All ports after the valve seat are at least 7.1mm so the valve seat and pellet probe are the smallest holes.

All the Impact ports and valve seat are the same size on other calibers other than the barrel transfer port and pellet probe.
 
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Ackuric, to get more speed beyond 85% single oblong jporting is to have dual iportningk &kwith same size khole the OD kof the porting is 3-4mm smaller to channel the air flow to the 2nd porting on the barrel while the 2nd porting on the probe is controlled by the size of the hole -- I start out with a 3mm porting and slowly enlarge the porting till I get the max speed till the next larger porting reduce the speed, now I get a new prod and drill the proper size 2nd porting, this way it won't be counter intuitive as you stated.

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The barrel transfer port on a .30 Impact measures 7.1mm right out of the box so that would be 92% would it not? The valve seat and pellet probe are much smaller so it seems they would be the greatest restriction.

Thank you for your advise.
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Thats so true Heavy Impact, thats why I design a new VS with 6.65mm bore and rode seat to match and dual port on the pellet probe.

next mod is to mill the valve housing where the VS is seated to accept a 7.1mm bore VS 
 
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Thats so true Heavy Impact, thats why I design a new VS with 6.65mm bore and rode seat to match and dual port on the pellet probe.
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Since the 6.65mm valve takes more force to open, was the valve rod strengthened?
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I think so, its made out of titanium plus its going to be tested at least 1k, I’m mostly consern about pressure drop with 165b using a larger bore, want to see if I gain any speed before increasing the reg pressure— I don’t really want to do that but in reality I need more air volume and that requires more reg pressure with all said and done I have to see low the shot count is to determine this impact has reached its limits at 165b.
 
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I think so, its made out of titanium plus its going to be tested at least 1k, I’m mostly consern about pressure drop with 165b using a larger bore, want to see if I gain any speed before increasing the reg pressure— I don’t really want to do that but in reality I need more air volume and that requires more reg pressure with all said and done I have to see low the shot count is to determine this impact has reached its limits at 165b.
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I look forward to buying your parts when you're ready to bring them to market.
 
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Ernest, as always, thanks for the real world information and pictures. Man, there's not much left of that valve tube :) Based on your comments about the valve rod threads, I turned my reg down from 180 to 165. It will drop the power a bit, but that's better than stripping the threads on the valve rod, particularly since I don't have a spare :)

(Holiday) Cheers,

Rusty


 
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Ernest, as always, thanks for the real world information and pictures. Man, there's not much left of that valve tube :) Based on your comments about the valve rod threads, I turned my reg down from 180 to 165. It will drop the power a bit, but that's better than stripping the threads on the valve rod, particularly since I don't have a spare :)

(Holiday) Cheers,

Rusty

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Rusty, it took awhile to stripe the threads I lost count over 1k till It strip. happened once out of 5 test gun. Plus we have a lot of impact parts to assemble a whole gun. Its fun to assemble the impact one part at a time and you will learn a lot by doing so. 
 
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FWIW, when you create a condition that has the restriction at the valve seat which appears to be the current case with some FX calibers...you create a ton of wasted volume (volume from seat to pellet base that has greater cross sectional area than valve throat) and actually LOSE power due to this, I have tested this both with real world tests and on paper. 



Ernest, you're doing great work with the FX's and the restricted confines you seem to be encountering. Rifle design unfortunately can be an inhibitor and due to me not having hands on experience with these models I wish I had more input/ideas to offer...



The closer you can get to the dimensions I list below, the closer the rifle is to 'peak performance' based on its barrel length/pressure/caliber..I hope you appreciate the work I put into these calculations/dimensions...these are all for 85% bore diameter porting and with use of a 3mm valve stem. 







The above is with a bolt probe area equivalent to 2.54 mm of a circle (pin style probe). With a flow through design that is full circle, the walls to the probe would have to be .01875" or .5mm, where as a half circle flow through style probe could be double that @ 1mm or .0375". My favorite probe design would be a 3/4 circle 'flow through' design that is .028" or .72 mm thick wall, where the circles break points are @ the port.
 
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Good post Matt,

Somewhat applicable as from what I can tell the Impact and Crown both use the same seat as the Boss. So far with my testing and reg pressure around 160 (I know a bit high) and with only 600mm barrels I've gotten;

62fpe in .22 with a 30gr

76fpe in .25 with a 43.2

The .22 is closer to your peak performance I wonder with the extra 4 inches of barrel how close it would be? I went from about 44fpe to 52 in the Royale by changing from the 500 to a 600mm. I think we are limited by the valve seat like you say and I agree, maybe the big upgrade would be to machine the blocks to accept a bigger valve seat other than that I'm not sure how much bigger the ID of the seat can go as Ernest seems to be at the limit.
 
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Good post Matt,

Somewhat applicable as from what I can tell the Impact and Crown both use the same seat as the Boss. So far with my testing and reg pressure around 160 (I know a bit high) and with only 600mm barrels I've gotten;

62fpe in .22 with a 30gr

76fpe in .25 with a 43.2

The .22 is closer to your peak performance I wonder with the extra 4 inches of barrel how close it would be? I went from about 44fpe to 52 in the Royale by changing from the 500 to a 600mm. I think we are limited by the valve seat like you say and I agree, maybe the big upgrade would be to machine the blocks to accept a bigger valve seat other than that I'm not sure how much bigger the ID of the seat can go as Ernest seems to be at the limit.
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I agree, the issue with larger valve seats is they are harder to open so that takes re-working of the hammer weight and or spring rating, but Ernest should have no issue down the road if that presents itself as the next obstacle.



FX sets up the valve currently to allow interchangeable calibers, which unfortunately throws a tiny wrench in the gears of peak performance. Its impossible to design 1 valve that works best in a .177 and a .30 cal without having a few other changes occur with the swap, such as valve seat/poppet geometry along with the other changes they currently implement.



Ideally you'd design the valve for your platforms largest caliber and have a design in place that restricts / limits wasted volume like a restriction plate / different sized transfer ports based on caliber. Barrel porting can achieve this but the volume from valve exit thru tp would be considered 'waste' so restricting air flow sooner is better for smaller calibers that don't need it. Not sure if the current FX valves have any restriction design in place, but with interchangeable calibers it should be. Even disregarding the wasted volume I believe its more critical to have adequate flow for a larger caliber than it is to lose a few fps and a shot or two on a small caliber. ie: build a valve for a .30 cal and work backwards or say eff it and let the barrel port restrict flow on smaller calibers, which simplifies hammer weight/spring ratios by not having 4 different valve seat / poppet geometries.



Glen...here are some numbers that may interest you. Top is current config of your .22 cal @ 160 bar 23.5 barrel with 30gr. Middle is 27.5" barrel with 30gr. Bottom is 27.5" barrel with 45 gr.




 
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Good post Matt,

Somewhat applicable as from what I can tell the Impact and Crown both use the same seat as the Boss. So far with my testing and reg pressure around 160 (I know a bit high) and with only 600mm barrels I've gotten;

62fpe in .22 with a 30gr

76fpe in .25 with a 43.2

The .22 is closer to your peak performance I wonder with the extra 4 inches of barrel how close it would be? I went from about 44fpe to 52 in the Royale by changing from the 500 to a 600mm. I think we are limited by the valve seat like you say and I agree, maybe the big upgrade would be to machine the blocks to accept a bigger valve seat other than that I'm not sure how much bigger the ID of the seat can go as Ernest seems to be at the limit.
Click to expand...



I agree, the issue with larger valve seats is they are harder to open so that takes re-working of the hammer weight and or spring rating, but Ernest should have no issue down the road if that presents itself as the next obstacle.



FX sets up the valve currently to allow interchangeable calibers, which unfortunately throws a tiny wrench in the gears of peak performance. Its impossible to design 1 valve that works best in a .177 and a .30 cal without having a few other changes occur with the swap, such as valve seat/poppet geometry along with the other changes they currently implement.



Ideally you'd design the valve for your platforms largest caliber and have a design in place that restricts / limits wasted volume like a restriction plate / different sized transfer ports based on caliber. Barrel porting can achieve this but the volume from valve exit thru tp would be considered 'waste' so restricting air flow sooner is better for smaller calibers that don't need it. Not sure if the current FX valves have any restriction design in place, but with interchangeable calibers it should be. Even disregarding the wasted volume I believe its more critical to have adequate flow for a larger caliber than it is to lose a few fps and a shot or two on a small caliber. ie: build a valve for a .30 cal and work backwards or say eff it and let the barrel port restrict flow on smaller calibers, which simplifies hammer weight/spring ratios by not having 4 different valve seat / poppet geometries.



Glen...here are some numbers that may interest you. Top is current config of your .22 cal @ 160 bar 23.5 barrel with 30gr. Middle is 27.5" barrel with 30gr. Bottom is 27.5" barrel with 45 gr.



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Very cool thanks for doing that, hopefully in the future FX can optimize the .30 a bit better like you say.
 
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Congrats on 2nd place! Those competitions are full of many good shooters and its not easy to place on the top.



I'll say this, if no one finds a way to modify a .30 cal fx rifle to obtain the energy outputs that I theorize, I will personally buy a dreamline in .30 cal if/when available and perform the modifications myself and sell the rifle here once complete for verification (have no personal need for 30 cal). I don't think this will be necessary, someone should beat me to the punch. Mark my words though, if no one does I will!



-Matt
 
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If your near Yalee FL you can test out the high power Impacts and crowns, at SPAW with Ken Hicks, Donny and I.

Brench Rest compittion on 19th January. I got 2nd place at Santiago Chile 75y EBR 😎 

You can plink, compet or watch and have fun with air guns crazy guys.
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Send me some to Chile so we can test it!!! 

2nd Place?! Sure! here some pics! (bravo!)

1545850335_19444555985c23cddfed1174.05035768_45959549_258793898118018_7058675422652792832_n.jpg


1545850336_15555910545c23cde02649c1.14748844_46083219_258794014784673_4179376729493602304_n.jpg



 
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