Greddy Profec Boost Controller HELP

[Taylor822]

I have searched and have had no luck finding help. I have a Greddy Profec Electronic Boost Controller on my S13 Silvia. SR20DET, GT2871R turbo with supporting mods (fuel, intake, exhaust, etc.).

I have been having a hell of a time trying to get this thing tuned. I have gone through and replaced every gasket, seal, and hose that could cause a boost leak. The car boosts fine when running on wastegate only, but the turbo response is much slower than using the boost controller. But when trying to use the boost controller, seems like no matter what settings I have, it will boost to 9-10psi, drop down to 5psi or so, then start building boost up to my target boost. The initial turbo response is amazing, builds boost super fast, but then it almost acts like the boost controller is limiting the boost or opening the wastegate prematurely.

The turbo has the stock wastegate so it has a 1 bar spring and is only a couple years old and haven?t driven the car much since I?ve been troubleshooting it a lot and working on it.

Is anyone else using this boost controller and if so what are your setting?

My setting as of yesterday are:
Set: 20
Gain: 15
Start : 15
Warning: 20
Limiter: 20

Thanks for any help!