Is a 46mm wastegate with a 10psi spring a good match for an s475 83mm 1.1 AR T6 on a stock head and cam lq9? I read on turbosmarts webpage, big turbo + low boost needs a big gate but it doesn't specify just how big the gate needs to be. The gate will be placed directly under the turbo exhaust flange. I will be using Tricks Twin Scroll T6 manifold.

 

It's plenty big enough to control boost... Even around 7-10psi range

 

Check out Synapse engineering they design the best blow off/by pass valve on the market truly. they are all tested to 200psi of boost pressure with zero leaks. it is what I run on my truck. Synapse Engineering | Official Page for Blow Off Valve, Wastegates, Intake

 

I would personally use a 50mm gate but 46mm gate should be fine.