Hi all.
Trying to tune my single turbo FC.

ECU: Haltech e6k.
Turbo: T04E 60 trim (vmount setup, very simple piping, BOV doesn't leak - )
External WG: Greddy 38mm - 12psi spring, lower port connected directly to the intake manifold as vacuum/boost source (basically boosting whatever the spring can do, which is ~12psi max). Top port is disconnected but not blocked. Doubt that it would make a difference if it were capped.

Problem: Boost spikes/jumps throughout the rpm range, and I have no idea why.
When using the EBC (Greddy Profec B) it still does the same thing, so I know it's not an issue of no EBC vs. using an EBC.

Here is a log of my last run. The boost is in psi (blue), the AFRs are red.
The orange line is for my own reference, so that I can tune for mid 10's fro AFR.
Disregard that the AFR, its not so great right now, I am just concerned with boost jumping around.


Any input would be much appreciated.

sil80

 

Where is your map sensor hooked up at? Lower intake or just after the t-body.

 

Just after the T body...

 

So, there are 4 vacuum ports in the back of the IM and 3 in the front of the IM, all of which are right behind the TB.
I was using the top rear port before, and when I switched to the top front, my vacuum/boost signal improved immensely (I also did a little fuel correction, but that's besides the point):



Does anyone know whether and which of the rear 4 and front 3 ports are good to use for sure?
I.e: Which ones of the below can I use for sure:


sil80

 

I am having similar issues, if i run through the gearshard it seems to perform well, but if I am pulling a hill just cruising out of boost then I go to accelerate, once I start boosting i get alot of turbo surge, to the point where my profec II will flash red even though I am under my warning pressure. Looks like moving your vac hose has helped maybe I will try that.
Oh I am running a EK6 as well with a greddy TD07 Turbo