Originally Posted by
Karlos G
Fair play DazC perhaps with a standard ECU this is the case and with Stu's chips.
You would not have infinite boost as the Amal is only bleeding off as much as the jet size allows.
Certainly with the chips I have used, Collins, Superchips, Ahmed Bayjoo, and Power Engineering, none of them have retained any sort of boost control that i've experienced.
Interesting to know though!
What you'd do then is set the boost using the actuator and the boost characteristics would remain, just with a higher pressure. If the valve was either open or closed then you would get total bleed off or none at all. Disconnect the valve and you will get no (very little, usually 4psi on a standard car) boost. Wire it up live all the time and the actuator will not see any air as it will all be diverted down the R line to the metering unit, hence infinite boost. It fails safe so air is ported to the actuator set to lift at 4psi and is then raised to 7.25 via the PWM signal bleeding off the actuator signal.
On my own car I set the actuator to lift at 1ps and the amal valve then increased it to peak 16 and hold 14. I then turned up the pre-load at a later date and the boost increased linearly (e.g. peak 18 held 16, peak 20 held 18).
On the other chips, they just switch the amal valve open to port air from the C port to the W port (switch off the amal valve). The jets will still affect the peak and hold characteristics but to have any form of boost you'd need to add a lot more pre-load to the actuator as no bleeding off is carried out by the valve anymore.