I just posted my build thread and I've had a pretty serious issue. I posted the issue in the conversion section, but I figured that I'd post it here as well:
Ideas?After resolving two different boost leaks with Mike, we went for some logs before dynoing the swap. What we found was that at about 3600 RPM at WOT, the car loses all boost. With less than 45% throttle, this issue did not seem to occur. We swapped N75s, measured vacuum to actuator during runs, change actuator length, swapped ECUs, and checked tunes. We were unable to resolve the issue. I don’t believe there is a rip in the actuator diaphragm because I tested it with a Mighty Vac when initially installing this turbo. We also tested vacuum between N75 and actuator. The ECU looks to be requesting boost, but vacuum drops between the N75 and actuator. I know it is not a rip in the vacuum line because the turbo is happy to hold 27-28 psi of boost pre 3600 RPM. The next steps are monitoring power to the N75 during runs to see if the issue is an electrical command/problem or if it is a mechanical issue with the actuator/turbo (extremely unlikely). While this is a problem that will majorly limit my peak power and stopped me from dynoing the R-TDI, this doesn’t really present an issue with everyday driving. I desperately want to solve this so that I can get a baseline dyno, but it will have to wait until I have time/resources to start fixing this. I have a deep suspicion that the issue has to do with an intermittent relay 109 code that occasionally shows up when scanning the ECU. If that is the case, this may take some serious work to solve. The issue could likely be a short in the ALH wiring harness as well. I am not sure yet, but I have some good places to start looking. All ideas welcome (thanks Matt [FixUntilBroke] and Mike L. for the ideas thus far).