Hey I'm kind of curious about something with my boost controller (profec b). Off = 5lbs (spring pressure) low = 10lbs high = 15lbs My low boost stays at 10lbs. I've never had to adjust it since the day I orignally set it. However, my high boost setting seems to fluctuate....by nearly a half a turn on the knob it seems. When it was colder outside, I had the knob turned maybe at 40%. Now its 70% plus. When the temp drops back down outside, I have to turn it back down so I don't over boost. Why is it that my high boost setting jumps around, but low boost is always the same?
Kind of understand duty cycle, but that still doesn't explain why sometimes i have to have the high boost at 10oclock and sometimes at 4oclock to maintain 15lbs....but low boost knob is ALWAYS in the same position to maintain 10psi
You basically have a manual boost controller that can be controlled in the cabin. It has no logic to compensate for heat, altitude, humidity, etc. Lower boost levels closer to your wastegate spring is easier to control.
That makes perfect sense. Thanks for explaining it. I had tried doing a google search, but didnt come up with much explaining why it would happen with high boost but not low boost. Yeah its a manual boost controller w/ knobs. Here it is. This picture was from when it was colder outside. I now have the high boost turned up about 5 or 6 dots from where its at in this picture. Is that normal to have to adjust it THAT much?