NefMoto

So my APB motor had grenaded itself after the timing belt snapped (Long story, it was a new belt). I swapped a BEL motor from an allroad, and swapped the K04s from my old APB to this new BEL. Wired it up, and all is well. Except that if I boost to 12 psi it takes around 4 seconds for the passenger WG to open completely and stay open until I let go of the throttle. If I boost to 16+ psi, it open immediately, and again stays open.

To test the N75, I've completely disconnected all the lines. Still same story. Replaced my DVs with my old spare ones, just in case it was the DV that opened, same thing.
I then disconnected the passenger WG line(from the 3 way splitter) and applied pressure then vac, to test for leaks. Nothing. After doing that however, I can now boost to ~14 psi with no issues.

I am going off my rocker here, and am hoping someone can help me, as well as pray that it isn't a god damn wastegate as I am tired of pulling the motor out (3 times in the god damn past month).

Also, did a log, the actual vs specified boost, car is still trying to run 10+ psi, while the actual can sometimes dip into vacuum while WOT. Throttle cut goes to max of 82%

One of the most important aspects of tuning is ensuring the hardware is right. You should always check wastegate preload, and synchronize them prior to install. Sounds like one of yours is hanging.

I have not changed the tune, nor have I changed anything on the turbo. As it came off the running APB motor, is how it is installed on the BEL. I've logged the runs, but the log is a bit shitty thanks to my slow vaggy. I also have a video of it occurring, uploading it now.

The shitty log
and heres the video
https://www.youtube.com/watch?v=IJIhguBnvq8

Just found a new fact, it only does this after 4k rpm. If I build boost in say 3rd up a hill, it runs and holds beautifully UNTIL I hit ~4krpm.

Another fact that I just noticed and remembered, my passenger intercooler was damaged as one of my coworkers threw a rotor in his bay towards a pile of my parts, so I used a stock intercooler temporarily, while retaining my upgraded one on the drivers. Which reminds me of how much of a fucktard I am, and will be putting the stock IC on the drivers side tomorrow. Hopefully that should resolve my idiocy. Thank you Daz for all your help once again, you truly are the audi god.

Turns out that wasn't it. Both intercoolers are now the stock ones. Replaced the N249, n75(race and the other one I had from my old motor), both diverter valves. I am not planning to change the entire vac and fuel rail system. I don't understand how a wastegate will just fail on its own after being transferred to another motor.

Log. Please not VCDS.

Sorry nyet, but my VCDS cable isn't currently playing nice with nefmoto nor any other cable. And one of my buddies jacked my galleto cable several months ago.

However, I can tell you that at exactly 4000rpm, WOT, 2nd gear, car requests 1910mbar, and gets 940mbar. Throttle actual angle at 100%, and engine load is at 71%.

And this seems to always happen at high boost levels (10+), and past 4k rpm. It's fucking driving me nuts, and I've just finished replacing the spider hose, and the entire vac & fuel rail lines. Including the injectors.

Next up is dropping the motor a few inches to see if I can reach and readjust the wastegate. It seems to only come from the passenger turbo.

Aaaaaand found the problem. Passenger wastegate. The rod somehow... detached itself.

so yeah, anyone know if a  K03 wastegate matches the K04 turbo for spring tension?

DO NOT DO THIS

You want the two wg's matched perfectly. Stop trying to save a buck here.

Is it possible to adjust the rods based on applying measured air pressure to the wastegates?

Yes but you still want to use the same wg for both turbos, because you really need the travel to be identical as well.

Don't bother doing any more work until you have a functional logging setup. You're just setting yourself up for wasting a ton of time and effort.

OE K03 and K04 actuators are the same. You won't have any issues running a K03 gate, as long as it's syncronized. I suggest setting both at 6psi, and ensuring the open at the same time.

Spooky that it was a wastegate huh?

The spring rates are different though, IIRC. So swapping in/out actuator bars themselves might be ok, you can't mix and match springs.

I am 90 percent sure that the spring rates are the same, and that the actuators are actually the same part number.

Last time I tried this I ended up with a setup that had the same opening pressure, but due to the way we had to preload one to get them to sync, the actuator range was totally different. Maybe a bad actuator?

Nyet, I feel offended that you think I'm stupid enough to swap just one out. I've got a set of brand new k03s lying around, and was planning to check the spring rate manually . Either way, I'll either replace the rod and sync the turbos to 6 psi as DD said, or I'll just try and see if the K03s work as well. Also with sync.

Also, I don't know how many times I said this but, I AM NOT TUNING ANYTHING!!! I already have a tune! I am just trying to get my engine to run properly again, as the APB motor did.

Apologies, no insult intended.

Definitely good to hear you'll make sure they're sync'd up properly. I just worry because I've been down that road and spent way too much time fighting misbehaving wastegates... something you kinda take for granted on single turbo projects...

I meant the "offended" playfully, don't worry :) I'll keep you guys updated tomorrow, as to how and what I do.

I smacked the wastegate rod back into shape. Turns out I somehow managed to bend it during reassembly. It works perfectly now. Thank you nyet & DD for all your help!

Nail, meet head.

AWESOME news, glad you got it dialed.