Has anybody ever monkeyed with the valve control knob right above the air bottle? Is it really an effective way to increase the power?
FX Impact Valve Control Knob
- Thread starter marcella69
- Start date
Its more of a fine tune knob I find right about 3 bars tends to give me the tightest shot to shot variation.
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I never mess with anything that's how you develop issues. The factory has them set perfect to specific calibers.
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I won't beat a dead horse about what the adjusters do, (that's already been well stated above) however because I'm a total geek and regularly switch between .177 and .30 I'm always adjusting both the power wheel and valve limiter. I've also tested reg adjustment in 10(ish) bar steps from 100-143 (ish)...
To start don't bother adjusting the reg... I used several tins of .177 and after the lead dust settled 125 and 143 both had roughly the same grouping (after adjusting the wheel and valve limiter of course) however 143 made it much easier to switch back to .30...
Power wheel- Simple to adjust and works great for the big adjustments. Although keep an eye on the fine tuning screw and lock tight it and/or mark it so you know when (not if) it moves...
Valve limiter- I adjust this with every time I switch calibers. Also I use it to fine tune the Impact to the best possible grouping with different pellet weights in each caliber. Right now you are probably wondering just how reproducible are the settings...
In my testing I get less than 1 meter per second variation in pellet velocity after adjusting back to previous settings! This led me to create a system for recording settings... 143-x-4-1 .30 & 143-m-1-8 .177 are examples of how I record my settings... of course your setting will NOT be the exact same as mine...
143 (reg press), m= min x=max (powerwheel) , 1= (number of white lines showing on valve limiter), 8= (length of lines on valve limiter knob)
So to complete this example... 143-m-1-8 in .177 equals 269 mps for a 10.34gn JSB... I can adjust settings or switch calibers and come right back to this setting by simply using this recording system...
Ok, I'm getting long winded here, but in short go ahead and adjust the heck out of the power wheel and valve limiter... just make sure to record your settings so you can find your way back...
P.S. Don't forget to make sure to never adjust the power wheel when cocked! Bad juju... To prevent stupid human error I never adjust any gun settings when cocked. Except the scope
To start don't bother adjusting the reg... I used several tins of .177 and after the lead dust settled 125 and 143 both had roughly the same grouping (after adjusting the wheel and valve limiter of course) however 143 made it much easier to switch back to .30...
Power wheel- Simple to adjust and works great for the big adjustments. Although keep an eye on the fine tuning screw and lock tight it and/or mark it so you know when (not if) it moves...
Valve limiter- I adjust this with every time I switch calibers. Also I use it to fine tune the Impact to the best possible grouping with different pellet weights in each caliber. Right now you are probably wondering just how reproducible are the settings...
In my testing I get less than 1 meter per second variation in pellet velocity after adjusting back to previous settings! This led me to create a system for recording settings... 143-x-4-1 .30 & 143-m-1-8 .177 are examples of how I record my settings... of course your setting will NOT be the exact same as mine...
143 (reg press), m= min x=max (powerwheel) , 1= (number of white lines showing on valve limiter), 8= (length of lines on valve limiter knob)
So to complete this example... 143-m-1-8 in .177 equals 269 mps for a 10.34gn JSB... I can adjust settings or switch calibers and come right back to this setting by simply using this recording system...
Ok, I'm getting long winded here, but in short go ahead and adjust the heck out of the power wheel and valve limiter... just make sure to record your settings so you can find your way back...
P.S. Don't forget to make sure to never adjust the power wheel when cocked! Bad juju... To prevent stupid human error I never adjust any gun settings when cocked. Except the scope
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Topcat, I do agree with you that messing with settings willy-nilly can result in disaster. (Nobody knows this more that I!) So, your point in that regard is well taken. However, with all due respect; although you've always given me good skinny in the past, I beg to differ with you on this one. The Impact was designed to have this adjustability. In fact, the Impact's adjustability is a main selling point. If done per manufacturer 's instructions, it will not void the warranty and can tailor performance to users' desires.
I am simply trying to increase power within manufacturer's guidelines. The advertised power was the main reason I chose the Impact .30. In fact, AOA has tuned my reg pressure as high as it can safely go without voiding the warranty, which has substantially increased power over what it was directly from FX.
Having said all that, thank you for your advice; I always take it under advisement
I am simply trying to increase power within manufacturer's guidelines. The advertised power was the main reason I chose the Impact .30. In fact, AOA has tuned my reg pressure as high as it can safely go without voiding the warranty, which has substantially increased power over what it was directly from FX.
Having said all that, thank you for your advice; I always take it under advisement
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Michael, OMG! Your research is amazing. It will take me a while to digest, if I'm able to! Thank you so much for that
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cactuscycles, thank you so much for your detailed analysis; it will take me awhile to digest it (if I'm ever actually able to!) It appears to me on its face that you rely heavily on field testing, which of course should always be performed to span the gap between theory and practice. Unfortunately, since I have moved from rural PA to SoCal, I have not had much luck finding a good spot to field test. At this time, I must rely on shot string and software analysis.
I got my Impact back from AOA yesterday after having the regulator rebuilt and the action tuned. I will be running a shot string today to see if the performance has actually improved. AOA has tuned my reg to 145.9 bar. I shoot the .30 JSB 44 & 50s with the power wheel on MAX (no play). The valve control knob is set just completely exposing the second small line. I'm looking to increase power and reduce SD. When I first got my new Impact, I was averaging 76.38 ft-lbs (SD: 5.00) with the JSB 44s, and 76.40 ft-lbs (SD: 5.26) with the JSB 50s.
I got my Impact back from AOA yesterday after having the regulator rebuilt and the action tuned. I will be running a shot string today to see if the performance has actually improved. AOA has tuned my reg to 145.9 bar. I shoot the .30 JSB 44 & 50s with the power wheel on MAX (no play). The valve control knob is set just completely exposing the second small line. I'm looking to increase power and reduce SD. When I first got my new Impact, I was averaging 76.38 ft-lbs (SD: 5.00) with the JSB 44s, and 76.40 ft-lbs (SD: 5.26) with the JSB 50s.
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