After driving my 7 for awhile at ten pounds figuring I needed a electronic boost controller or to adjust the wastegate, I noticed I had crazy boost leaks, fixed those, now It's currently zipping right past 20psi if I try to go anywhere near half throttle or more.

I'm running an HKS sport turbo kit, with the HKS divided mani, though i swapped out the compressor wheel and housing for a GT40 Precision cold side. Boost is supposed to be controlled by the HKS dual port wastegate actuator, and I have the waste gate passages ported to the limits really of the gate door and as far as I felt safe with the runner walls.

I have the line from the cold side to the actuator port closest to the compressor housing, and the port further away from the cold side, vented to atmosphere. Is this correct? I wasn't 100% sure about this actuator but from what I found online this seems correct.

The wastegate arm is adjustable as well, I have the arm adjusted to the point where there is just enough pressure pulling back from the actuator to hold the door closed kinda firmly. That would equate to the lowest base pressure able to be held by the actuator correct? I imagine having the arm tighter would take more pressure to open the gate?

I'm tempted to just disconnect the arm leaving the gate door open to see if I am just creeping to that extent.

If anyone has any ideas to try, or knows anything about the adjustable actuator that I don't lets hear it.

Thanks

Matt

 

those kits creep bad. Internal wastegates are not rotary-friendly, especially with the larger 82mm compressor wheel you have on there. I had the exact same turbo last year, and ended up welding the flappers shut and running an FD HKS divided cast manifold with external wastegate. I would really suggest doing this. It's not only about the size of the WG runners on this kit, but the placement. I believe the largest you can go is a little over an inch in diameter each runner? Even that is only equivalent to a ~36mm wastegate, with **** poor runner placement.

Now, as far as the internal wastegate goes, I believe you have it setup properly, but test the bottom port with compressed air and a regulator to make sure it's cracking at about ~8psi AFAIK. Top port vented. If that all works, then switch out manifolds and get a proper wastegate.

 

I figured as much, I know we've talked before about this setup Trots, I guess there isn't any avoiding it, Ill test the actuator but your probably right, I'll have to go external.

 

It sucks, I know. I was determined to get it to work, but failed miserably

Last option could be to remove the actuator arm and flappers, bore the hell out of the runners, and modify the back housing to seal the wastegate runner area from the turbo discharge, and weld a flange on the back cover to fit an external wastegate to it. Someone did this with an S5 hybrid before, but it's a lot more work and close to the same price as the other alternative.

 

I had this idea as well, just take the back plate off, weld in a divider, make a flange for an external gate, The only thing is that wouldn't help much seeing as what is restricting me now the exhaust would still have to pass though, like you mentioned most likely the runners.

That would most likely be futile, though I know I've seen the thread where its been done before, I'll go back and reread it see how it turned out for him.

Another idea, though space would be a concern, cutting a hole in the manifold and welding the gate there somehow.

More than likely I'll just have to find a different manifold just sucks, going to have make new lines, modify the DP, oh well.