If you don't mind I would appreciate more info to try to sort this out and get the confusion out of my head. As I understand it:
Assuming all other factors are the same (bolt, barrel, dwell, etc.) In order to maintain the same fps by dropping air volume or air pressure you need to increase the other and therefore the same bang. By changing any one of the factors (bolt, barrel, dwel, etc.) you hope to improve the efficiency and therefore are able to drop either the air volume or air pressure while still maintaining the same fps.
[*]If I use a lighter bolt it takes less air volume or pressure to drive it therefore higher efficiency and less bang.
Correct. But with the difference in bolt weight being very small, and the distance the bolt has to move small. this effect is marginal.
The Stock bolt loses alot of air out of the tail when its moving.
If you take the body cover off and fire the gun you can feel this blast of air. This is much more significant than the energy needed to move the bolt.
Thats why most bolts alter the design of the tail area, either by adding more orings or removing the tail completely, to give an improvement in efficiency.
Thats also why the QEV helps the efficiency of a stock ion so much, but an upgraded ion less so. Because it speeds up the bolt giving less time for wasting air.
[*]If I use an insert I get a better ball to barrel fit and consequently don't waste air through the gaps between the barrel and the ball so I need less air volume or pressure to push the ball out at the same speed. Just need to make sure I don't use a too small insert in order to not need more air volume or pressure to overcome the friction between the ball and barrel. So again higher efficiency and less bang.
Remember the paintball travels the length of the barrel in a blink of an eye.
Air takes the path of least resistance, which is not squeezing past the crack between a speeding paintball and the barrel wall.
You have to overbore by quite a bit before you really see changes in efficiency.
Those in the business of selling multi peice barrel kits, will claim increased efficiency, accuracy and whatever else they can think of from sizing your barrel to the paint.
Its not based on actual evidence, testing or anything like that.
Its just made up to get you to part with your cash. They would tell you it would increase the size of your wedding tackle if they thought it would get you to buy it.
The reality is most people use one large bore barrel for large paint and one medium for the rest, because there is no difference from messing around with kits and inserts.
[*]Heavy porting comes in play after the ball has achieved max velocity by going through a snugly fitting insert. From that moment it is just a question of releasing the air as gradually as possible in order to get more of a hiss and less of a bang. During this faze the velocity of the ball might actually be dropping.
Yes, got it in one. The noise comes from a very quick change from high pressure to atmospheric pressure.
A ported section allows that transition to happen slower. Causing a longer sound which contains similar energy but doesnt seem like as harsh of a bang.
Thats why the barrel has the largest effect on sound signature compared to anything else.
Get hold of a 4 inch barrel and you will know what I mean haha...
Its a little 2 button pad people stick to the back of their ions grip frame in preference to the annoying stock button.
Stock 180psi, don't know the stock dwell but must be higher as well. I assume that means that you have significantly improved efficiency by having reduced both the air pressure and air volume. That should mean less bang and sounds good to me.
Lowering both the pressure and the volume will reduce the velocity your paintballs are firing at.
You can either have a high pressure, small volume, less efficiency losses.
Or low pressure, large volume, high efficiency losses.
I could be all wrong about this but that is the picture in my head. Please correct me if I am wrong so I don't go off spending money on completely the wrong stuff.
Seems like you got your head around most of it.
There is alot of snake oil in the Ion upgrades market.
I shouldnt be so critical of some of the products.
But it upsets me when somebody sees an ion with (for example) a hollow point or an L7 and off the back of that they go and buy one of these non-upgrades like the firebolt. (ALIHISGREAT there is nothing wrong with the firebolt, its just not really an ugprade).
Its no wonder alot of people sell their ions after upgrading.
The only way to be sure about most upgrades is to get hold of one and judge it for yourself.
By the way how do you measure the psi in your marker?
You can make a pressure tester that screws on to your reg out of an old ASA and a pressure gauge.
Just for reference, our teams ion setups are 220psi with a volume spacer.
Always L7 or hollowpoint bolt.
Those with QEV, the dwell is around 12-18.
Without QEV (but with mac noid) dwells around 28-32.
Our Ions can be set to shoot 300fps with 100psi and a dwell of 8.
Its just that in the interests of maintainig perfect concistency during rapid fire, we choose not to set them up that way.