So I have been messing with my boost by gear settings for a while now. I can't seem to get first and second gear to run the amount of boost that it's set to run. Its running lower. I have a mac 4 port and at first I was having fluttering issues that I got to go away by setting hz up to 45. Got my dc for boost table setup then pluged in what I want to run in each gear. Can't get 1st and 2nd to run high enough. I keep uping the boost for each gear but it doesn't raise it really.

 

You may not have enough load in those gears to even make the amount of boost you're looking for.

Do you need the dynamic range the 4 port solenoids offer? (3psi spring and need 30psi of boost?)

 

What spring rate do you have in the wastegate?

 

6 psi spring. didn't have a problem last year running 23psi every gear with manual controlerror but it was too much

 

What size turbo ?

Also make sure your wastegate activation pressure setting is correct, this needs to be the same or close to your actual spring pressure, otherwise the solenoid can remain inactive and therefore you won't get target boost as the solenoid is remaining passive in the lower gears.

 

I run the VitViper PWM booster with a 4 port mac solenoid and the duty cycle vs psi increase is almost a 1:1 ratio. 3rd and 4th gear require a little more duty to maintain pressure but with a 6psi spring I'm able to run 35 psi with <50% duty cycle. I think the problem is with a 4 port that most of the time the duty cycle increase vs pressure increase is never linear so you just have to play with your settings or find a better boost controller.