I only have 12, 17 and 24 psi springs. I was always told that I should run half to two thirds target boost as the spring rate.

17 sounds good. I was told wg spring can handle up 200% rated psi assuming no boost creeping.

using the Perth-WRX mobile app

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MY08 STI 422whp at 1.5bar on E85, built by Diversion Garage, assembled and tuned by EvoR

Update from new owner: 375whp at 1.4bar on 98, at Tokyo Motorsport

I think external gates tend to allow the turbo to run closer to peak performance levels but too much effort required for custom fabrication for me to worry.

If I will lotto then I may build a big rotated mount externally gated toy but for now it is back to reality.

I meant the other way around.

My understanding is boost control's function is to chock the air from post turbo to actuator.

My butler dp has very little gap for wastegate flow, as the result, boost creep from 1.3 to 1.5 bar at top. Im only on 70 wgdc with 0.8 bar spring. The dp is doing some work for boost solenoid.

If u r hitting the boost with higher dc, that means ur invidia dp is not restrictive.

using the Perth-WRX mobile app

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MY08 STI 422whp at 1.5bar on E85, built by Diversion Garage, assembled and tuned by EvoR

Update from new owner: 375whp at 1.4bar on 98, at Tokyo Motorsport

Did some more testing last night after my latest version tune still didn't manage to raise boost past 12psi. Confirmed plumbing was correct on ebcs.

I disconnected the vacuum line to the wastage and went for a gentle drive. Didn't take much at all to hit 15psi. My ebcs seems faulty. Also discovered that it buzzes when the ignition is on but engine is off.

I will try and grab a new one today. My tuner has given me a new map with some lower settings for i, sport and sport sharp so that we can confirm that this is the problem, without me suddenly smashing 30 psi into the engine by mistake.

Got to love cars. So many learning opportunities! ;-)

I also tested the swing of the wastegate flapper yesterday to ensure that it was able to move through its full range of motion. No problems here at all. Go invidia.

I have heard that with bigger turbos that have bigger flappers that they can hit the inside of the dump housing as you have said may be the case with your Buttler design.

What about the hole size in the waste gate.

I always set my actuator 5 full turns (about 6-8mm) shorter from the flappers closed position - there should be a substantial amount of actuator spring pressure holding it closed.

Otherwise your wastegate will leak during spool & induce lag/wastegate creep.

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[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

Will give this a try. Thanks for the tip. It is actually a difficult topic to research as it usually just ends up being boost leaks. Up pipe, BOV or outlet/y-pipe causes.

Mine is different as if I disconnect the wastegate actuator I can easily go past the current boost levels.

thats normal.

wastegate actuator needs pressure to open. if you disconnect it, it wont get pressure, and it wont open. And the boost will continue to increase.

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Doing it for all the wagons out there