Since I got my new Zelos I've been obsessed with its tunability, particularly regulator pressure vs hammer spring tension. Thanks to the knowledge and experience of members here, I've learned a lot. After many test sessions with a chronometer and varied regulator pressure vs hammer spring tension I've developed a theory which I present for critical review:
Out of the box, the hammer spring has little or no tension and the regulator is set to about 1800 psi and this combo seems to be the top of the fps curve for that pressure. As regulator pressure is increased, increasing spring tension by one turn in for every 200 psi increase seems to give the highest velocity. (but not necessarily the most efficient setting) Here's how it charts out:
psi vs turns in to yield max fps
1800 psi - 0 turns in
2000 psi - 1 turn in
2200 psi - 2 turns in
2400 psi - 3 turns in
2600 psi - 4 turns in
2800 psi - 5 turns in
I didn't test beyond 2600 psi, so any thing beyond that is just extrapolation.
Out of the box, the hammer spring has little or no tension and the regulator is set to about 1800 psi and this combo seems to be the top of the fps curve for that pressure. As regulator pressure is increased, increasing spring tension by one turn in for every 200 psi increase seems to give the highest velocity. (but not necessarily the most efficient setting) Here's how it charts out:
psi vs turns in to yield max fps
1800 psi - 0 turns in
2000 psi - 1 turn in
2200 psi - 2 turns in
2400 psi - 3 turns in
2600 psi - 4 turns in
2800 psi - 5 turns in
I didn't test beyond 2600 psi, so any thing beyond that is just extrapolation.