Is this a legit site? Kinugawa wastegate actuators?

https://www.camposites.com/product/ct15 ... e-actuator

I have no experience with this place. It seems to be toyota specific mostly. Has anyone used this place?

I'm having boost creep issues on a ST215 swap into my ST165. I'm wondering if a better actuator will help?

what turbo and what is the current wastegate pressure spring ?
You can test if your current wastegate actuator is working properly (if you have an air compressor, small is sufficient) by putting the air nozzle on it after regulating it down. For me with my 7psi actuator, I put 10 and then 15 psi to see just how far the door was opening (not 100% until 15 to 20 psi, the door just linearly opens further the higher the pressure.).

If your actuator is good, then you may have to port the turbine housing and wastegate port. I had to on my gtx2860r as I was getting 7psi until 5k rpm, then 10, then 12, then 16-18-20 on the way to 7k rpm.

If you do end up having to port out the housing, there are a lot of guides on rx7club and other rotary forums - fd's have big problems with boost creep after just installing aftermarket downpipes. You want it to look pretty close to the second picture here: https://www.miataturbo.net/general-miat ... ial-80058/ but smoother and with a bit more material taken out. You want the exhaust gas to smoothly find its way to the flapper door. Be careful with actually porting the door itself - you need to leave enough material behind so the door doesn't bind up and get stuck. I left 1/8" just to be safe on mine.

If you are just running the oem ct15 that has that awful all-in-one cast manifold and turbo... godspeed.

Yep. Stock CT15. I have another CT15. Looks like I can clean up the casting...maybe improve it a bit. I just want a reliable 15-16 psi.

it's too bad that you can't separate the turbine housing from the manifold to really get at it from the top. Just be careful when you are enlarging the flapper door hole. If you go too big, you'll have to weld in a larger door. When I did mine, I used spray paint over my housing's flapper door to see how much area the door actually covered, then removed as much metal as i could while retaining 1/8". While working from inside the door, you can smooth out some of the metal on the inside of the housing. I suggest leaving the bottom part as straight as possible and only smooth/taper/etc the top part (the path closest to the upper exhaust manifold section). You want to make it as easy as possible for exhaust to find its way to the flapper door, not keep moving past the door and into the section where the turbine wheel is.

Oh, and in case it wasn't clear, you def need to pull the CHRA and just work on the hot-side alone. I don't think there's any way you could safely grind and not leave some metal bits inside the turbo somewhere.

best of luck. I hope you are able to resolve your overboosting issue.