mobeeno
Contributor
How important is it to have the correct IP setting for different second stages to be paired with certain first stages?
IP settings
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Well, if you want the second stage to operate at it's design performance, it's pretty important to hit within the spec range on IP. If you can stand a little extra propensity to freeflow or a little more cracking effort & breathing resistance, then the importance is less so...mobeeno:
Rick
Unbalanced second stages will tend to freeflow if they are put on a first stage with a significantly higher IP than the one to which they were tuned.
Conversely unbalanced second stages will tend to have an excessively high inhalation effort if used on a first stage with an IP significantly lower than the IP of the one to which they were tuned.
Balanced second stages are a bit less sensitive to changes in IP, but tuning the IP to the IP of the specific first stage on which they will be used is still critical if you want peak performance.
The IP range used by nearly all manufacturers is 120 to 145 psi. which is a pretty broad range. If you want to be able to mix and match first and second stages over the course of a season, you need to have the tech set the IP the same on all your first stages and tune all your second stages to operate at that IP.
Generally speaking, an IP at the high end of the range is desireable as, like turbocharging a car engine, it allows more mass flow through a given system in a given amount of time. There are exceptions however as, for example, a 120 psi IP on a Scubapro Mk 25 makes it a bit more reliable in very cold water (and it has more flow rate than it needs anyway even at 120 psi.)
Conversely unbalanced second stages will tend to have an excessively high inhalation effort if used on a first stage with an IP significantly lower than the IP of the one to which they were tuned.
Balanced second stages are a bit less sensitive to changes in IP, but tuning the IP to the IP of the specific first stage on which they will be used is still critical if you want peak performance.
The IP range used by nearly all manufacturers is 120 to 145 psi. which is a pretty broad range. If you want to be able to mix and match first and second stages over the course of a season, you need to have the tech set the IP the same on all your first stages and tune all your second stages to operate at that IP.
Generally speaking, an IP at the high end of the range is desireable as, like turbocharging a car engine, it allows more mass flow through a given system in a given amount of time. There are exceptions however as, for example, a 120 psi IP on a Scubapro Mk 25 makes it a bit more reliable in very cold water (and it has more flow rate than it needs anyway even at 120 psi.)
