The reason you don't see any threads on low boost GT3582r's is because that would be running them outside of their efficiency range. Had a friend that tried doing this on an H22. I told him that boost creep would be a real issue because a GT35 wants to be spooling to 25psi. Trying to hold it back is going to be difficult and it will be so very laggy compared to the t25 set up. In fact, because the t25 is so instantaneous, it wouldn't surprise me if it wasn't quicker with the tiny turbo versus the the GT35. They just aren't a good match with small bore 4 cylinder engines. And when it does creep, you won't be able to control it. It will sail up to 20 or so pounds of boost and then that minty fresh Z6 will be scattered to the breeze, and pavement. I've see this happen multiple times with people using the gt3582r and wanting a low boost setup. It just isn't the turbo to try that with. You would do better with a gt2860rs. It will bolt right in place of the t25, make whatever power you're trying to make without breaking a sweat. 7 psi would get you to that magic number of 180 wtq. 18psi will make over 300whp. Just some thoughts and my experience.