Thanks guys!
pmuller9: The brick wall is from blowing through the converter. There is just enough left in this converter when cool(not been boosted), that is stalls to 4700 and pulls great leveling off slowly such as 5600 rpm described earlier. After is has been boosted once and the fluid is warmed up, it shoots to 5200 and stays there. You really have to actually ride in a turbo car that's blowing through the converter to get a good grasp of whats going on. Andre at Edge Converters confirmed that it can limit rpm. The other v6 was the same way, until the new converter.
I have put thought in the exhaust pulses, and also considered different cam profiles catering to the 120* firing. You cam and ignition lead a 5hp racing Briggs and Stratton differently than a multiple cylinder engine as well. Low timing helps pulling out of the corners toward the checkered flag on those...anyway... The whole exhaust system is under pressure fluctuating 5psi pressure with pulses on my best gauge. Depending on flow, anything with a Y in it and more time could cause reversion up the other pipe, not good. The log on the other hand, is like a balloon with six straws in it. Don't matter which straw is blowing or when, its flowing out the hole. The efi mani's have terrible bends in them detrimental to flow and reversion could occur there too.
The bottom line: I have see horrible turbo plumbing to the turbo, only to be done proper later with zero benefit. Real world testing is the only way. My truck spools great with excellent back pressures, no reason to change things. I do understand where you are coming from in theory however. The efi mani's could work better, headers with proper heat treatment could work better...Their is a guy selling 1000hp mod motor turbo kits, he will sell you his headers or you can use your manifolds. He said dyno testing showed no difference in power.
Agreed, turbo boost keeps pressure in the cylinder and on the piston....keeping the rod alive. Low timing and proper AFR's save pistons and head gaskets.