Just more turbo talk for people who want to know more on how turbo's work. Let me remind you that this is HRC turbo setup.. i think stars have an external wastegate(?).

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Mystic511: what's the actuator do?
MUR1X: sets the boost level of the turbo
MUR1X: sets when the wastegate opens
Mystic511: isn't boost level set by boost controller?
Mystic511: see why i'm confused? heh
MUR1X: a boost controller bleeds off the signal sent to the wastegate as to trick the turbo into seeing less boost so the wastegate does not open
MUR1X: the actuator is the actual spring controlled arm that is attached ot the wastegate to open and close it
MUR1X: all turbos have a point where the wastegate will open which is controlled by the actuator and this is the lowest point you can set on the boost controller. It is impossible to open the wastegate at a lower setting than what is set by the actuator
MUR1X: without a wastegate the turbo would just keep spooling
MUR1X: it bleeds off air
MUR1X: a slow acting wastegate can actually cause lag
MUR1X: but is is smoother
MUR1X: the profec b has a setting for this
MUR1X: mild/sharp
MUR1X: you can control how smoothly it opens/closesd
Mystic511: the 9 psi actuator would force me to run at 9 psi or higher?
Mystic511: or up to 9 psi?
MUR1X: it would mean you always run at least 9psi
MUR1X: BUT
MUR1X: it would actually be around 7-8psi due to pressure drop
MUR1X: which is why it works out perfectly for stage II
Mystic511: ah, ok
MUR1X: it opens at 9psi at the turbo which is actually 7-8psi at the manifold
MUR1X: depending on your setup - intercooler etc
Mystic511: so the closer i mount the boost gauge to the intake mani.. then the more accurate it will be
MUR1X: exactly - for an accurate reading it should receive a signal from the actual manifold
MUR1X: the S20G comes with a 15psi actuator
MUR1X: it is impossible to run less than that on Armonds car
Mystic511: so would it be ok to run s20g with a 9 psi actuator or would that just break things?
MUR1X: it would work but would not be worthless
MUR1X: but would be worthless I mean
MUR1X: big turbos might be more efficient
MUR1X: but at low boost levels it does not matter
MUR1X: because you are not pushing the smaller turbo hard enough really
MUR1X: once you are there then look into a larger turbo
MUR1X: besides, it only costs $500 to convert a S16G to a S20G
MUR1X: large turbos at low psi in my mind do not make a faster car, only a more peaky and laggy car
MUR1X: to justify a large turbo, you need to run a lot of boost where they make more sense