I've been having some issues with my car hitting boost cut (22psi) in 3rd. I checked the waste gate and the lines and everything looks fine. My laptops been down for a couple months, so I cant see whats going on in the ecu. I decided to hook up a needle valve between the top of the waste gate and the mac valve to bleed a little pressure off (with a t fitting and about 7-8 feet of line, so I can adjust as I drive).
First pull, it worked, it now only hit 11 psi. Then I started to close the valve to raise the boost to my target... 18psi. The funny thing is that it never got there it only got to 14psi, even when the valve was completely closed.
I figured I had a leak in the connection or the valve, so I folded the line over on itself to seal it and added a ziptie. While doing this, I effectively shortened the line to about 5 feet. Now it was hitting around 16 psi. Now I'm wondering why its not hitting the boost cut, so I shorten the line to about 3 feet and seal it. What do ya know? 18 psi!
My thought is that changing the volume of pressurized air connected to the top of the waste gate changes the pressure achieved at a given duty cycle. It seems that I always have to adjust my duty cycle across the board from winter to summer, maybe just changing the "pinch point" in this line will be a simpler solution?
I still don't know why I had the problem in the first place though, maybe the mac valve is clogged or shitting itself? I don't really care right now, I just wanna hit the track on full boost.
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Topic: Discovered something interesting working on a boost controller issue (Read 2895 times)