PFS PMC boost control
 

I just got the Interacq software. Does anyone know how the pfs pmc actually controls boost ? The explanations on wades page make no sense. He says more primary vent means more pre-spool. But more venting = more primary boost = less pre spool. Is it an additive over the stock vent value ? Is primary before 4500 and secondary after ? In other words, if I put 20 in the primary vent value for 10 psi and I'm at 3000 rpm, boosting 10 on the primary, will it add 20% to the duty cycle?
And if I go to 11 and I have 30 it will add 30 and so on ? Otherwise, the numbers should go backwards, right ? You would vent 100% until 10psi and then you would start venting less to control boost. All the screen shots I've seen the vent goes up with the boost.

you should just turn the vent value on, go take a couple of hard runs and then turn the vent value off and you are good to go.

by the way, where did you get the software and how much?

Software is available from Plus One Micro. Email Paul (the author) at plus1m@mindspring.com. List is $299, but he may discount for direct sales. Vent learn was turned on and the values were kind of strange - 25 65 57 93 75 - that sort of thing. I'd like to control it directly. I'm going to try some vent settings today and see what happens.

do you have the latest software on the PFS or not? I don't have the latest software. Mine says 1996 and I don't know if the Windows software would work.

Amel

You would probably need an eeprom upgrade. Paul can tell from the numbers on your chip. After thinking about it, I guess the vents are what should produce that boost. 0 = 7 psi, x=8psi, y=9psi, z=10psi. So if x is 25 and your target boost is 8 then the pfs will vent at 25 to try to get 8 psi. If it is learning, and it gets 9psi at 25 then it could try a lower value.

Who is this Paul guy and can he upgrade my PMS to the latest software? Is he related to the PFS company?

Amel

Paul wrote the software. The PMS has an eeprom chip which can be upgraded. The latest software works only with the later eeproms. I think EFI systems has the eeproms.