correction is off
It's set at 16

 

You want the gate to open before you hit target boost, let alone wait til 6 psi above it Turn gate pressure down to a setting a couple psi below your target boost.

 

So my target boost is right around 21psi. So set the gate at 18 then?
SP1 is at 40 and sen is 20. These sound right?

I'd like it to stay at 21psi if I can under load.

 

Yeah you can try 18. If it overboosts, turn the gate pressure down a bit. If boost takes a while to settle, turn sensitivity down. Also, SP1 at 40 for me is like 15psi. Around 50 is 20psi. Might be different on your truck.

 

It spikes to 20 and then settles to 10. Tell me what to put in there and I'll try it.

 

Oh, I see. In that case, turn sensitivity up. See what 25 does.

 

I set the SP1 to 50
GP1 to 18.5
SN1 to 25

Max boost was 22.5psi. It jumps right up there and drops off. What needs to change to make it stay closer to 20psi?
Turbosmart doesn't recommend the sensitivity be over 30.

 

It sounds like your solenoid to wastegate lines are reversed. Like its not letting any air to the wastegate until 18psi, it spikes to 22 right after, and then applies boost pressure to the bottom of the wastegate and opens it back up. That's just what it sounds like.

 

I checked them and they're hooked up like the picture I posted.

 

I wonder how it'll work if I use two port method 1 connection. Says single turbo with high back pressure. Leaves port 3 to the atmosphere, port 2 to the top of the wastegate, port 1 to pressure source with lower wastegate port tee into pressure source line.