One thing I want to warn everyone about with the GTM kit and internal wastegates: If you want the option of running < 10psi and you aren't running a stock exhaust/cats, don't get them.
I made such a big deal about how theres no reason for externals and its a waste of money blah blah blah, now I feel like an idiot. Our engines flow a fuckton of air (technical term), the end result is that in 3rd-6th at 6k+ there is basically TOO much air flowing for the internal wastegate ports on the Garett turbos. I have the actuators at basically 0 preload, just enough tension on the flapper to keep them from rattling at idle, and I had boost creeping to 13psi at redline in higher gears.
You basically have 3 options for controlling boost creep when you have too much exhaust flow:
1.) run external wastegates, large wastegate opening flows more air, duh.
2.) port the internal wastegate housing, have to remove turbos
3.) restrict the exhaust flow (add backpressure)
I am working on option 3 right now, I have re-installed my old invidia gemini which is smaller diameter and more restrictive path than the aam 2.5". This reduced my creep from 13psi down to about 11psi, which is great but still not what I want. My next option is to either install high flow cats in place of test pipes, or install exhaust restrictors. An exhaust restrictor is basically just a metal plate you install in place of a gasket that has a smaller diameter opening.
If I was made aware of this issue when purchasing, which I wasn't, I would have gladly just went with external wastegates and recircd. I am not blaming GTM for this issue, but this is something they ABSOLUTELY should make clear when people purchase the internal wastegates.
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