Thought I'd share what I've been up to recently. If you didn't see my other post about the map sensor, I'll recap a lil. Comparing my boost gauge with torque pro, I noticed the engines map sensor would stop reading at 22psi. Thinking I had a faulty sensor, I started researching and found out that the crd's stock sensor reads up to 2.5 bar. 1 bar = 1 atmosphere, or 14.7 psi. Since the sensor is an absolute sensor (that's what the "a" in map sensor means) it reads from true 0psi, which is 30" of vacuum. This meant that the engine couldn't see the additional boost my setup is putting out, and therefore couldn't properly control the fueling.
I found another sensor that would fit but is rated for 3.5 bar, or 36psi of boost. This will let the computer control the fueling all the way up.
I also started putting things together for a compound turbo setup. I needed a gt35r turbine wheel with a 71mm compressor wheel, in a gt28 center housing. Only problem, they don't make it! The largest turbine wheel the 71mm compressor comes on is a gt30, I need a gt35. Tried seeing if it would work, but no one has done it, so me being me, I ordered parts (thanks crown royal). Came in the other day, so I snapped some pics, turbo is sent out getting put together with some custom machining on the compressor wheel to fit it to the larger turbine shaft.
Here you can see the billet 71mm compressor on the left, the gt2560 wheel in the middle, and the crds stock 56mm wheel on the right. That is a lot more airflow.
The gt35 wheel on the right is 1.6 times bigger than the gt25 wheel on the left. Ideally you want the second turbine wheel to be 1.5 times the size to properly scavenge the leftover energy from the first turbine. The exhaust is cooler, less dense, and takes up more space, which is why you need a larger turbine to properly handle the flow. My next option is a gt30 wheel that is 1.4, I opted for the larger size for safety.