[swarfman64]

We have lift off!
Here's the short version. I had a faulty map switch which played havoc with my wide band self tuning setup. So, now its fixed I can push through the flutter and get to some good throttle openings. Yep she hauls. I've limited boost to 9psi while I sort a base map. I believe the flutter is caused by too small a turbine housing, spooling up way too early so part throttle the compressor is pumping too much air and surging. With larger throttle openings its all good because there is a place for that air to go. Solution (if my theory is correct)is to use a part throttle open waste gate which opens during cruise or machine 0.010-0.020 thou from the turbine housing and make it a little less efficient. Street riding it is quicker than it was before using only 5000 to 8000 rpm, top gear pulls between 7000rpm and 10000rpm are better than a non turbo acceleration between 9500 to 13000 in 3rd gear. Lots to sort yet but I'll refine this set up to 9psi then build the new motor with the gt12 turbo. cant get the smile off my face.