why is there a tee on the line to the wastegate? there shouldnt be. i want you to hook the n75 up like this, and only this. no extra lines, no nothing else. also, note the differenet length nipples and what they are used for. don't mess them up. also, grab the wastegate acuator rod. if you can so much as jiggle it, you need a different wastegate.

 

The line coming from the wastegate is too small to fit on the N75 nipple, that's why I think they used a junction and a bigger hose to connect it to the MBC's nipple (same size as the N75). I don't know if they changed the stock line with a smaller one, I can try to see if warming up the rubber I can fit it on the N75's nipple with no extra stuff.
Right now I'm tring to figure out how to fix the wire, I tried today but between the 8F that was today's weather and the fact that it got detached right where the wire connects to the plug I had no luck...
Whenever I can work on it with a slightly better weather Ill make sure the nipples are connected to the right spots: on the picture the right to the wastegate, the lower to the rubber air intake hose, and the left after the turbo, correct?

 

No. The right one is wastegate, bottom is turbo, and left is intake

 

Thanks! I'll make sure to check the position of each one when I take it out and report back.

 

Ok so I reconnected the wires with a new plug (from a Passat) to the N75 today. I also checked the nipples and they are plugged in the right way (bottom turbo, side long intake, side short wastegate). I tested the car and now the boost pressure reaches around 4psi, which is pretty much what it was doing before with the MBC, maybe slightly less, but the car feels a still slower.

Does this sound more like a bad N75 or a pressure leak? Also if I have to replace the N75 would an E revision work properly? Almost all the N75 I see for sale are either the race H version or the E.

 

Update: I unplugged the line going to the wastegate and took the car for a ride. I carefully accelerated and the boost had no problem reaching 10psi. I think I need a new N75, and Im probably gonna get the E revision.

 

So I bought I new N75 (E revision) and installed it this morning. The connections are correct as from the schematic above. I test drive the car and still get only 2-4psi. WTF??? The only other thing I can think about is the MAF is malfunctioning and is sending the car in limp mode, so maybe the N75 wasn't the problem... But I'm starting to worry that there's no end to the problems in this car

 

It is possible your MAF is sending an incorrect reading. You can simply clean the sensor with rubbing alcohol or MAF cleaner and go from there (there is a DIY on this forum).

Also have you performed a boost leak test? You never know...

 

I wanted to try cleaning the MAF and I read the DIY, but I can't unscrew the weird *** bolts with pliers so I'd need to find that specific tool. And Im also thinking if I clean the MAF and the boost still doesn't work, how do I know that the MAF is not screwed (and cleaning doesn't fix it)?

Disconnecting the wastegate I was able to bring the boost to 10psi so I don't think it's a boost leak.

 

If you completely disconnected the wastegate you should boost a lot more than 10. You have an another issue