Hey guys, readers digest version.
I've got 2 turns of preload on my 20psi turbosmart wastegate.
Issue I'm having is I can't tune my ebcs low enough for it not to surge in 4th and 5th.
Will going to normal preload allow me to tune the boost lower in the affected rpms with no issues holding boost up top?

 

You can give it a shot but my guess is that is not the issue. Without knowing your setup, the most likely cause of the boost creeping up is the internal wastegate passage itself, not the actuator. To cure that you would need to port the housing or at least try a higher flowing o2 sensor housing. A lower spring in the actuator could help too. I am running a Turbosmart internal wasteage actuator as well with an 18psi spring and have it setup with the preload as recommended.

 

Setup is stock block, hks 272 cams, Tdo6sl2r/20g, aem 320, fic 1800s, straight 3" tbe, Muse short route charge piping, aem 3.5 Fmic and a map o2 housing

 

New hotside vs the old hotside.
Can see everything is bigger.

 

Your 20 psi WGA is likely your problem. Typically, internal WGAs can hold boosts to double its spring rating. So if you wanted to boost a maximum of 24 psi and lowest of 18 psi, you should have gotten WGA closest to 14 psi. With 20 psi WGA, the lowest you can boost is 22 psi and there's no guarantee that it won't spike over a bit.

 

I don't have issue with boost too high. My goal is 30lbs to Redline, issue is in 4th and 5th it surges from 3500-4k rpms.
Builds boost too quick.

 

My tuner pulls about 3 percent off 4th and like 6-8 precent from 5th for WGDC.

 

I'm running boost by pressure(psi) , not by duty cycle. I've tried with it set to 10lbs thru those ranges but it still surges.
Maybe i should just try it with the ebcs open on those rpms