I couldn't find ay dual waste gate plumbing diagrams, I'm not sure if they are suppose to run in series or in parallel pictures are alays a good reference to me.

also on the waste gate line do i have to run it into the intercooler tubing or can i run it into the upper intake manifold? (right after TB)

 

Boost refferance usually from compressor housing or on intercooler piping as close to turbo as possible, to the bottom nipple on 'gate. Have a look at installation manuals online for your wastegate if you havnt got it, or if knock off brand check tial or turvosmart sites or whatever. They all work the same way. For twins just Tee everything.

 

i have 2 tial 38mm mvr wastegates, I'm just going to tap in a nipple on my turbo

 

im doing a 6266 on a 12a what gates do you recomend? 38mm or should i go with twin 46's?

 

A well placed single MVR (44mm) will be plenty fine with a 6266. I ran my 6265 with a single MVR with no issues.

 

used a 44 tial on 67mm no issues, held 8psi if wanted

 

what manifold and exhaust setup do you have .