Hey guys, I know forums are way less popular now, but just wanted to give it a shot here.

I have been battling boost issues for a couple months now, and just wanted to look for a second opinion before just keep throwing things at it.

I'm running a MAC 3 port ebcs, to a FP red. The 19psi wastegate actuator is 4 turns preloaded and is new as that was a separate issue. A BLT was done before doing these logs.

One picture below is of wastegate pressure; the AFR and boost is rock solid. The other one is with WGDC set to 40%, and as you can see, the boost is fluctuating quite bad, AFR's go wonky, and the whole car rocks back and forth. Last one is with the WGDC at 25%, and that's holding steady...

Also, there was a time when I mistakenly ran without boost control, the car hit 30psi no problem and held it for around 700rpm with no hiccups.

 

i would set the wgdc to 0 and then see how it acts on spring only.

if it does the same on just spring, then its something in your wastegate.

if it doesnt, then i woulld guess the mbc

 

I essentially did it by looping the hose from the WG to the turbo. It holds rock steady boost.
I did more testing today, and now it seems both a mbc and a ebc does not control boost. Both systems have the same fluctuation, and boost does not increase with wgdc change and not with the mbc fully cranked.

I'm completely stumped. I'm leaning towards a WG problem, but I don't want to drop 200 bucks on a new one. Sigh

 

Check your 3 port.. wire one wire to positive acc, and 3 port sol will "tkats" on to ground other wire.

 

I don't know what you mean haha. the 3 port is operational both testing it with the software, as well as testing it with 12v and ground. As for the wiring its just wired up to the original BCS wiring, standard stuff.