So I think I am on to something with my shutter/miss issue at higher boost. This is a turbo 6.1 on E85. I have a full fore fuel system with solid fuel pressure. I have reviewed countless logs and the only thing that stands out is that when I get up past about 11psi my AFR's drop down to 0.68. When I am around 5-10psi they are typically around 0.75 on the lambda scale. Also, NGK 6510 plugs are gapped @0.024.
The car runs absolutely fantastic up to 10 psi, but then will pretty consistently miss above that and that is where my AFR's seem really rich @ 0.68.
3 logs are attached showing the boost/AFR scenarios. Open to any suggestions to lean this thing out a little at higher boost!
tune.hpt <<<Tune File
lowboost.hpl <<< 9psi boost log=0.75 lambda (no miss!)
Highboostmiss.hpl <<< 13psi boost log=0.68 lambda (miss/sputter)
Highboostmiss2.hpl <<< 13psi boost log=0.68 lambda (miss/sputter)