Boost control question......

[1hawaiian]

I HAVE A MAC SOLENOID HOOKED UP TO MY S300. MY QUESTIONS WAS IM SETTING UP MY BOOST/GEAR/DUTY CYCLE. I HAVE IT SET TO ONLY ENGAGE IN 3RD GEAR BUT AT 5000RPM AND HAVE IT SET PAST THAT. I HAVE THE ACTIVATION PRESSURE AT 8PSI. NOW MY TURBO IS 57TRIM AND .63A/R BUT IT COMES INTO BOOST AT 4500. NOW AT 4600 MY DATA IS SHOWING THAT THE SLOENOID KICKS IN AND STARTS BOOSTING UP TO 30%DUTY CYCLE WHICH I HAVE IT SET TO BUT ITS EARLY, @4600 INSTEAD OF 5000RPM. I WILL LOAD THE DATA LOG AND CALIBRATION WHEN I GET OFF WORK BUT ANY IDEA'S WOULD BE APPRECIATED.

[MarkC]

I'm having a hard time understanding what you are trying to do. The PWM output will start outputting to the solenoid at the activation pressure, no matter what the RPM are. So if you are getting 8psi by 4600RPM, then the you will see 30% on the PWM data. That is good thing.

I don't know whay you are only having it set to engage in 3rd gear and at 5000RPM? To set it up you should be using the "Fixed Duty Cycle" option at 30%. Then see what boost level that gets you. Then change to 40% and do another run... record boost level. Etc, etc up to 80% or the highest boos tyou want to run.

[1hawaiian]

I SEE....I WAS UNDER THE IMPRESSION THE ACTIVATION PRESSURE WOULDNT ENGAGE TILL 5000RPM. I KNOW I HAVE IT AT 8PSI BUT I THOUGHT THAT IT WOULD JUST ARM IT IN THE ECM THEN ACTIVATE THE SOLENOID AT 5K. I HAVE IT SET UP.....5000 5500 6000 6500 7000
DUTY CYCLE.......50.......45.......30......30......30
THIS IS MY SETUP IN 3RD GEAR, WHEN IT HIT 8PSI AT 4500 THE SOLENOID IS RIGHT AT 30% DUTY. EVEN AS I PULL TO 5500RPM IT STAYS AT 30%.

[1hawaiian]

HERE IS MY LOG AND CALIBRATION.