i've been working with an 02 GTI 1.8T i recently picked up on the cheap to experiment with. it was a factory 150hp car as the original ECU part number was 06A 906 032DL. the BIN and XDF i've been using is from the cars 180hp counter part and its part number is 06A 906 032HS. overall the BIN works great stock and the car definitely wakes up a bit but my problem is when i adjust any of the suggested mapping to try and get some more boost out of it there seems to be no affect. on WOT pull in third i only see 10 to 11 pounds and bleeding down to 8 psi by red line. if im rolling at light load in third and floor it the boost will spike up for 12psi than bleed down to 8 again.

the car was a pretty badly molested car, the previous owner had all the vacuum lines out of whack and what i did to cure that was what i feel simplify the vacuum lines down to just 4 lines. 1 is for the diverter valve, 2 is for the N75, 3 is for the FPR and i put a T off of the FPR for the boost gauge which makes 4. the rest of the vacuum ports are blocked off on the intake. i edited ESKONF as per instructions to do away with everything emissions related. there's no N249 anymore, no SAI pump, i made a block off plate for the EGR on the side of the head and installed it and shut down the tank vent valve, downstream oxygen sensor is deleted too.

this is what my ESKONF looks like.
AA FF 00 F3 FF FB FC

i also followed what to do to set the readiness up and delete everything as well and over all everything seems to be working right on that end as i have no CEL for any of that stuff and readiness is always up.

the car has a pretty much stock engine, i put a brand new K03S on it from ebay, it has an ebay FMIC kit, ebay 3in downpipe and full 3in exhaust, forge splitter diverter valve, ebay cold air intake. most of the stuff was on the car when i got it.

over all i know there's a good bit in this car and i cant figure out how to get it out of it. im on the border of figuring out how to ditch the N75 and put a manual boost controller on it so i can get the boost levels i want and work with timing and fuel from there.  i attached the BIN file from my last attempt at trying to get any gains out of the car. im not looking for criticism, im asking for help because i cannot see what im doing wrong. every thread i've read says change this and that. i feel like i ended up changing half of the mapping and just screwed the BIN all to hell. the car does run and drive fine it just lacks any gains at all.
please help me find the errors in what i've done. thanks guys.  

i put 3 different N75's in it with all the same results. thinking about just doing away with the N75 all together and going with a manual boost controller. tuning all these maps is a PITA especially when nothing has any affect on how it runs. only thing thats helped is adding some timing to it and adjusting the target lambda table with the boost the way it is.

forge splitter because it came on the car when i bought it and its better than a stock plastic valve. 90% of the stuff was on the car when i bought it. its getting an audi TT 225hp intake that faces the drivers side and all new intercooler piping made because the current ebay piping fits horrible and i think i can build a cleaner looking setup based off the TT intake manifold.

it has nice polished surface 

because they make cool "bro noises" ?

I'd typed up a reply last night but fell asleep.  The Forge Splitter is the worst, they leak like hell, and it's pretty much a BOV, but can redirect "some" flow.

The 1.8t management is NOT suited to this - as the lost air isn't account for.

The standard 710n valve is a diaphragm based valve and perfectly capable of holding 26 psi - as mine has for 140k in its life (the last 20 with atleast 23psi).  No leaks.

The Forge based stuff is piston actuated - which HAVE to leak, as they cannot perfectly seal.

Anyway, I'd be replacing the valve and starting with a boost leak check.

What maps have you changed?  A list of them, a good WOT log pull - WITH ME7Logger, your .bin and your .kp would be useful.

FYI the splitter on this car does not vent to atmosphere, i have that portion capped off. not sure if you realize they come with caps to block either or side to make it full atmospheric or full recirculation. i just like the adjustable hat, makes my life easier to get it dialed in for whatever boost levels the car is running.