Problem with plenum

[villaman]

My mate fitted the same kit to his mk 1 with out drilling out anything and gained another 10 fpe 

 

[heavy-impact]

My mate fitted the same kit to his mk 1 with out drilling out anything and gained another 10 fpe

Maybe your mate can fix your problem.

 

[edosan]

The only reason for fitting plenum , to gain more shots

by the way using 33.9 gr mk2 JSB

Larger plenum will not give you more shot. Who told you that? The air in the plenum is regulated. Even if you have a 100 Cf for your plenum. Once you shoot, it is falling in pressure so you are not getting additional shot. If you want more shot, why not get the 580cc bottle? It has 100cc more air at 3600psi vs your large plenum which I'm guess is about 40cc at 150 bar.

You do get more shots if you reach the same velocity at lower regulator pressure.

Disagree, you do not get more shots out of the plenum only, with the plenum you are replacing pressure for volume, the amount of air used is about the same. Yes you use less pressure, but consume the same amount of air. BUT if you add more modifications like elongated TP, bigger VS, will make the air flow more efficient and you will save some air.

 

[GQ]

Generally speaking....

Slugs are more accurate at higher speed compared to pellets ,,,right or wrong ?

So to be able to shoot slugs at the top higher speed you need all the modifications done...right or wrong ?

For the same weight of a slug you will need less pressure from the regulator to get the same speed when all the modifications are done....right or wrong ?

Let say that to get the same speed you will get your regulator pressure set down to 135 bar compared to 150 without modifications......................right or wrong ? 

 

[edosan]

Slugs are more accurate at higher speed compared to pellets ,,,right or wrong ?

RIGHT: IME Pellets are more accurate in the 850-900 range and Slugs are more accurate in the 900-950 range, BUT some slugs are very accurate un the 800-900 range. And some pellets and Slugs are amazing at 1.000 fps so is relative (and accurate, maybe not SUBMOA but moa for sure)

So to be able to shoot slugs at the top higher speed you need all the modifications done…right or wrong ?

WRONG: that will be depending totally on the weight of the slug, YOU CAN shoot slugs accurate out of a non modificated gun, as long as the weight is similar or less than pellets.

Today Impact can shoot slugs pretty good without any changes, even without a SlugLiner (some slugs, usually the lighter ones). New impact when arrives, will manage much more weight on slugs. (more power)

For the same weight of a slug you will need less pressure from the regulator to get the same speed when all the modifications are done….right or wrong ?

Not sure about your question, and will depend on what modifications you are making, and why are you making those mods.

Let say that to get the same speed you will get your regulator pressure set down to 135 bar compared to 150 without modifications………………….right or wrong ?

Usually Right

 

[edosan]

Which I can’t and that’s the problem 

l will give it another go , after that I will sell the kit . My mate has gained another 10 fpe on his mk 1 from 46 ft/lbs up to 56 and shooting fantastic .

If I understand correct you tune your impact, then you add your power kit, and shoot, and that is about it?

Is that right? if it is...Men, as many stated here, you need to tune your airgun from scratch any time you made a mayor change, and a power kit IS a mayor Change.

Also you should "reroute" your questions to the one that sell that to you, he/she knows better about their specifics and gain you should expect!

 

[Bob_O]

The new FX Hybrid slugs are accurate at lower velocities.

I had them shooting tight groups at 55 and 105yds.....870fps from my Impact.

 

[heavy-impact]

The only reason for fitting plenum , to gain more shots

by the way using 33.9 gr mk2 JSB

Larger plenum will not give you more shot. Who told you that? The air in the plenum is regulated. Even if you have a 100 Cf for your plenum. Once you shoot, it is falling in pressure so you are not getting additional shot. If you want more shot, why not get the 580cc bottle? It has 100cc more air at 3600psi vs your large plenum which I'm guess is about 40cc at 150 bar.

You do get more shots if you reach the same velocity at lower regulator pressure.

Disagree, you do not get more shots out of the plenum only, with the plenum you are replacing pressure for volume, the amount of air used is about the same. Yes you use less pressure, but consume the same amount of air. BUT if you add more modifications like elongated TP, bigger VS, will make the air flow more efficient and you will save some air.

You didn't read the whole thread, did you ?

 

[edosan]

The only reason for fitting plenum , to gain more shots

by the way using 33.9 gr mk2 JSB

Larger plenum will not give you more shot. Who told you that? The air in the plenum is regulated. Even if you have a 100 Cf for your plenum. Once you shoot, it is falling in pressure so you are not getting additional shot. If you want more shot, why not get the 580cc bottle? It has 100cc more air at 3600psi vs your large plenum which I'm guess is about 40cc at 150 bar.

You do get more shots if you reach the same velocity at lower regulator pressure.

Disagree, you do not get more shots out of the plenum only, with the plenum you are replacing pressure for volume, the amount of air used is about the same. Yes you use less pressure, but consume the same amount of air. BUT if you add more modifications like elongated TP, bigger VS, will make the air flow more efficient and you will save some air.

You didn't read the whole thread, did you ?

I am quoting the whole thread? maybe the plenum you "invented" is different 

 

[villaman]

Which I can’t and that’s the problem 

l will give it another go , after that I will sell the kit . My mate has gained another 10 fpe on his mk 1 from 46 ft/lbs up to 56 and shooting fantastic .

If I understand correct you tune your impact, then you add your power kit, and shoot, and that is about it?

Is that right? if it is...Men, as many stated here, you need to tune your airgun from scratch any time you made a mayor change, and a power kit IS a mayor Change.

Also you should "reroute" your questions to the one that sell that to you, he/she knows better about their specifics and gain you should expect!

Yes , I had a tune done, transfer port hole , pellet prob mode , heavier hammer weight and spring guide . Running at 160 bar 970 FPS about 35 shots using mk2 JSB 33.9 gr pellets . Very smooth to shot 

so I thought by adding a plenum kit which came with plenum , modified valve housing , transfer port with 2 elongated holes , pellet prop which has been cut away and heavier hammer weight / spring guide 

I thought with this kit I should be having more shots at a lower reg pressure at the same FPS Or have I got it completely wrong with my thoughts ?

These kits are well made I must add and it’s worked very well on my shooting partner impact 

 

[villaman]

Should I try the original hammer weight which is obviously lighter?

 

[heavy-impact]

I am quoting the whole thread? maybe the plenum you "invented" is different 

Yeah it's probably like the one you saw before the impact was invented.

 

[edosan]

Which I can’t and that’s the problem 

l will give it another go , after that I will sell the kit . My mate has gained another 10 fpe on his mk 1 from 46 ft/lbs up to 56 and shooting fantastic .

If I understand correct you tune your impact, then you add your power kit, and shoot, and that is about it?

Is that right? if it is...Men, as many stated here, you need to tune your airgun from scratch any time you made a mayor change, and a power kit IS a mayor Change.

Also you should "reroute" your questions to the one that sell that to you, he/she knows better about their specifics and gain you should expect!

Yes , I had a tune done, transfer port hole , pellet prob mode , heavier hammer weight and spring guide . Running at 160 bar 970 FPS about 35 shots using mk2 JSB 33.9 gr pellets . Very smooth to shot 

so I thought by adding a plenum kit which came with plenum , modified valve housing , transfer port with 2 elongated holes , pellet prop which has been cut away and heavier hammer weight / spring guide 

I thought with this kit I should be having more shots at a lower reg pressure at the same FPS Or have I got it completely wrong with my thoughts ?

These kits are well made I must add and it’s worked very well on my shooting partner impact

You need to start your tuning from CERO all over again, no need to add a lighter hammer. Is not plug and play, is plug, tune and play. And 99% sure is not a "kit" problem

 

[villaman]

Yep the kit is all good it’s probably me 

one question, would put spring guide ,spring then hammer weight or spring guide into hammer weight then the spring ?

 

[GQ]

Just watch how Ernest Row fine tune.

https://youtu.be/PdY3i62mhow

 

[GQ]

villaman, did you measure this ? To make sure the transfer port is perfectly aligned with the barrel brass port.

 

[villaman]

villaman, did you measure this ? To make sure the transfer port is perfectly aligned with the barrel brass port.

No what do I measure?

 

[GQ]

Watch the picture carefully. It must be between 44.45 to 45 mm

 

[GQ]

I suggest that you watch and learn all the Masterclass FX Impact video.

You will fine all the details.

Ernest give us the details in this video what to measure and how to adjust.



https://youtu.be/TGyUkswtdws

 

[heavy-impact]

Yep the kit is all good it’s probably me 

one question, would put spring guide ,spring then hammer weight or spring guide into hammer weight then the spring ?

The hammer weight replaces the plastic spring guide. They are never used together.