Just a new IC, injectors and turbo? That said my guess is either a part of your tune or a pressure loss from faster injectors without a faster fuel pump. Most times I recommend that drivers upgrade their injectors with the pump at the same time, In your case If you have a stock pump it would have 10 years of gunk in the filter as well and when the engine is asking for more fuel it might be the bottleneck. I would pull a few logs and look at your actual AFR, if its looking lean during those RPM levels that could be a sign of a pump.
I would also stop running past redline : / If you've only done injectors, IC, and turbo then im pretty sure redline is around 7 not 8. Its not worth running the RPMs that high, most tunes peak around 5,500 RPM, shifting at 6,500 with proper technique t should keep you in boost range and isnt such a risk to the bearings.
13 WRX Hatch - Cobb OTS Stage 1