16G boost problems

[CrashGNX]

So ive got a Big 16G on my 1g AWD with a stock motor. Ive been fighting for almost 2 weeks now to get boost under control. Ive got a HDI electronic boost control, Ive tried my dejon MBC, ive tried using DMSlink v3 to get the boost dialed in and stay there. So far to no avail.

With my HDI It spikes to 20-25PSI then falls to somewhere in the 10-15 range and varies back and forth in a 8-10psi yoyo effect depending on where I have the boost set. Ive tried using signal from the turbo elbow and direct from the intake manifold. Both do the same thing pretty much. Ive tried putting a .24 boost pill in on the boost signal side to hopefully smooth it out but that didnt work either.

With the Manual boost controller, I went as far as dialing it almost all the way up to where I should have been pushing somehwere in the 25+ range but barely got over 16lbs at spike and 10psi average after.

Trying to manage it with every different combination I could think of on ECU link turned out with even worse results until I gave up.

I figured at this point that my wastegate actuator is either screwed up or something is definitely wrong with it internally. so as a last ditch effort I unhooked all the boost controllers and plugged off the elbow port and left the actuator hose off so it wouldnt get any signal aka no boost control. I got the best spool ive ever seen out of it and boost never fell off a bit until I let off the throttle at 24psi. So I know there isnt anything wrong internally and I know its not just blowing the wastegate open internally (with no boost control hooked up).

I figure its gotta be my actuator is just too weak for the 18-20psi I want to run, as soon as it gets any kind of boost signal it cracks open and gets overrun and blown open until it can shut again when the boost gets low enough.

The solution im going to try is I bought a Force Motorsports adjustable actuator for a EVO X off ebay. got it cheap, $110 vs normal cost of over $220. and I will mod my current bracket to be able to bolt the new one on kinda like putting a Holset actuator on it. My Big 16G has a straight actuator arm instead of the normal curved one anyway and is adjustable. I figure I can just drill out the spot welds holding the old one to the bracket and drill holes for the new one to bolt through, screw on the best length adjusting rod and bolt it back on the car. Hopefully I wont even have to run a boost controller but we will see. I didnt want to use a Holset HX30 actuator because I believe my boost would be held at a minimum of 24+ PSI and I dont want to go that high right now.

Any thoughts of why this wont work or what I should have done?

Thanks

 

[Dsmkauai]

Just get a holset acuator from Justin. It fixe my spike problems and since it's adjustable it works well. With my boost controller 0'd out I see 15psi boost and the arm is only half way turned in. I'm sure I could get it to 18psi if I turned it in more but I need alittle lower boost in 1st gear to help with tire spin. He sells then for like $45-50 shipped bro, and it has a straight arm like yours. I just fabed a bracket and bolted on took less than an hour.

 

[CrashGNX]

Do you know which Holset actuator he used?

Last night I had some time on my hands so I turned down the rod for my wastegate actuator until it only had about 1/4- 5/16 of an inch of travel from closed to maxed out open. Tested it out and my boost is now controllable and doesnt spike or creep back down that I could tell. It did seem to have some lag building boost above probably 4200 or so but its at least controllable and not spiking and dropping anymore. This definitely wasnt the right way to fix the problem, more of a workaround but seems effective in a pinch. Basically what I caused to happen was the wastegate doesnt have enough throw anymore to be blown open to the point of not being able to close until pressure drops but it still opens enough to allow the boost to be controllable. Its probably a small threshold between opening too much and not enough and its probably different on every turbo depending on your build and how worn the turbo is.

My new actuator is already on its way and paid for so ill just use it instead of a holset. Guess I paid another $65 to have one I can swap out springs in !