So about a week ago I noticed sporadic boost issues on the car during heavy acceleration where the stock boost gauge would bounce all over the place. I figured that my Turbosmart WGA needed adjustment so when I inspected it, I realized that I could freely move the arm up and down on the flapper which meant I had no preload on the WGA. Relatively simple fix I thought and adjusted WGA per this video below with 2mm of preload:
Once I got it readjusted, I disconnected the battery and the ground to the ECU for 20 minutes to reset it and went on a drive. Things looked good and the boost needle on the stock boost gauge was more stable however it tapped out at 18PSI (and stayed there) which was not normal for the tune that I am on. While in boost, I noticed a "whirring" sound so that could only mean one thing, a boost leak. Got under the car and noticed that the EC charge pipe on the passenger side split a couple of inches from the turbo. Another easy fix I thought and grabbed some scrap aluminum piping I had laying around and replaced the damaged section of the EC pipe. Emailed EC some pics of the split IC pipe and they are sending me a replacement pipe with a lining that is chemical/oil resistant. Great service from EC as always and the replacement pipe should arrive sometime on Tuesday.
So after I replaced the damaged section of the charge pipe, I went on a drive to test things out. Good news, the car is holding boost and pulls like a son of gun at 24PSI however in 3rd gear under heavy acceleration, it seemed like the BOV was cracking under acceleration at 1 second intervals above a certain RPM (can't remember the RPM) and subsequent 1 second intervals. Not sure how to describe it other than :acceleration "brief pshhhh" acceleration "brief pshhh" acceleration "brief pshhhh": and so on. I chalked it up to the ECU still adapting due to the WGA adjustments I made and just left it at that and drove home.
Later that day I had to run some errands and decided to test it again and low and behold, the BOV was no longer cracking at 3rd gear under acceleration and all seemed well. Figured that the ECU finally adapted to the WGA adjustments and just left it at that. Yesterday, I got on the freeway to run more errands and unfortunately, I was greeted with the issue again but this time, it was happening in 5th gear at 3100 RPMs. The issue was easily replicable and the car seemed to let off boost briefly at 3100RPM with the repeating :acceleration "brief pshhhh" acceleration "brief pshhh" acceleration "brief pshhhh": As a test, I dropped it in 4th and accelerated to the point where upshifting to 5th would get me past the 3100RPM BOV cracking and it seemed to not do it in 5th after I got the car past 3100RPMs. The stock boost gauge remained at 24PSI thereon past 3100RPM.
I am a bit puzzled as to why this is happening in 5th gear now and not in 3rd gear anymore. Could it be that I need to back off the preload on the WGA to 1mm vs 2mm? Is my BOV intermittently failing at higher boost pressures and perhaps the blue spring in the BOV is weak and needs to be replaced? Any thoughts or insights that anyone can provide in getting that issue resolved would be of great help.
Thanks again and look forward to the responses of this odd BOV cracking under acceleration issue.