Amazing air efficiency of my Impact

Jump to latest Follow Reply
A tune of modest velocity using very short valve dwell can be extremely efficient. The Impact has a 480cc bottle so your efficiency works out to 2.41fpe/ci.

There have been quite a few well-substantiated tunes producing over 2fpe/ci and a couple that approached 2.5 but they required significant modification, custom parts, and tuning effort. One notable example is motorhead's heavily modified Marauder with full-bore porting, a custom valve, lightweight hammer, and SSG (anti hammer bounce device):
https://www.gatewaytoairguns.org/GTA/index.php?topic=148788

That's a kind way of saying I think your numbers have an error or two :)
 
  • Like
Reactions: Tony_Du
Upvote 0
A tune of modest velocity using very short valve dwell can be extremely efficient. The Impact has a 480cc bottle so your efficiency works out to 2.41fpe/ci.

There have been quite a few well-substantiated tunes producing over 2fpe/ci and a couple that approached 2.5 but they required significant modification, custom parts, and tuning effort. One notable example is motorhead's heavily modified Marauder with full-bore porting, a custom valve, lightweight hammer, and SSG (anti hammer bounce device):
https://www.gatewaytoairguns.org/GTA/index.php?topic=148788

That's a kind way of saying I think your numbers have an error or two :)
Click to expand...

Yes, i can not believe that, that is why post the result here, i think must be something wrong there, 20 minutes ago, 7 shots, pressure changed from 170 to 155, the gauge is Wika, that means 2bar for 1 shot, totally confused.....
 
Upvote 0
A tune of modest velocity using very short valve dwell can be extremely efficient. The Impact has a 480cc bottle so your efficiency works out to 2.41fpe/ci.

There have been quite a few well-substantiated tunes producing over 2fpe/ci and a couple that approached 2.5 but they required significant modification, custom parts, and tuning effort. One notable example is motorhead's heavily modified Marauder with full-bore porting, a custom valve, lightweight hammer, and SSG (anti hammer bounce device):
https://www.gatewaytoairguns.org/GTA/index.php?topic=148788

That's a kind way of saying I think your numbers have an error or two :)
Click to expand...


Just as an FYI .... here a few pictures of what my custom Cobra valve looks like in my High efficiency marauder.



1559536503_4693456045cf4a37720cf97.28313027_DSCF0590_50.jpg
1559536522_14808061365cf4a38a4d1f06.67533274_DSCF0591_50.jpg
1559536539_1437773575cf4a39b0eae79.21973366_DSCF0593_50.jpg
1559536555_15642061005cf4a3ab1af602.90699503_DSCF0594_50.jpg


Sadly .. or not really sadly the gun no longer sits in this configuration due to wanting to play with .177 SLUGS, this valve as configured delivers a high pressure pulse of such short duration there simply is not enough volume of air released to get a heavy slug moving and up to sufficient speed. launching pellets however it is the bomb !



Scott s
 
Upvote 0
2.3 FPE/CI ~ is the theoretical maximum efficiency an airgun can achieve and that is generally at a severely reduced pellet velocity while using the shortest valve dwell possible that releases enough air to push the pellet out of the barrel. Anyone getting close to this or surpassing it likely are mistaken by flawed equipment or calculations...



-Matt
 
Upvote 0
2.3 FPE/CI ~ is the theoretical maximum efficiency an airgun can achieve and that is generally at a severely reduced pellet velocity while using the shortest valve dwell possible that releases enough air to push the pellet out of the barrel. Anyone getting close to this or surpassing it likely are mistaken by flawed equipment or calculations...



-Matt
Click to expand...

Source?
 
Upvote 0
tuning a PCP is not really too difficult...it takes, mostly, time and patience.

right now i have my standard 25 caliber, Benjamin Marauder tuned to get 35+ shots...from 2900 PSI to 2000 PSI. i have not chroned for best performance/power yet. it generates enough FPE to completely penetrate 5/8" plywood at 65 yards...more than enough to meet my needs. i'm certain that further adjustment of the striker would yield more FPE...but will reduce shot count.
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu