Just picked my car up from the shop. I switched to APR 1+ chipped mode, but the car felt stock, if that. It drove smooth and fine, and it was boosting some, but not much. I was thinking limp mode, so when I got it home I scanned with vag-com, and there were no codes. I then logged requested vs. actual, and even when requested exceeded 2200, actual never went above 1300 or so.

I called the shop and they said they checked for vacuum and boost leaks and found none. They also said I would hear a boost leak, but I don't. Could it be something to do with the wastegate actuator or N75?

I'll be bringing the car back on Tuesday, but in the meantime if there's something simple to check, I will. I already checked the N75 hookups to make sure they were correct. The long nub goes into the TIP, the nub opposite the long one to the wastegate, and the remaining one into the turbo.

Here's a log of 115 (requested vs. actual) and 119 (N75 duty cycle): http://www.patzcatz.com/audi/log-01-115-119-xxx.csv

Thanks again...

 

not my area but it does seem like the vac pipes are crossed one can only try

 

Not sure why they would be around the N75 for replacing the turbo. Sure doesn't look good.

My K03 runs at 2.1-2.2 and logging shows right pressures with the ECS N75 race valve.

 

The N75 is on the TIP and has two vac lines going to the turbo housing and wastegate actuator. So it would be touched. I verified it was hooked up correctly. Maybe some shavings from the old turbo got into it and messed it up.

 

Go to a4mods.com and check out his easy and cheap boost leak tester. Of course the usual check your hose connections disclaimer that everyone says "Duh" on. On the B6, leaks always seem to occur at the scution jet pump. But your requested vs. actual (based on what you say as I haven't opened the logs) is much bigger than what that would cause.
On mine, I had about the same thing. Requested was max that VAG COM would show, but I was maybe getting to 1400 and real late in the RPM range at that. Checked everywhere for boost leaks. No leaks. Ended up finding out that wastegate actuator was stuck open. So, maybe check that.
Hope you find it. Many leaks actually can't be heard and some can't be seen. Cracks in hoses only opens up under boost and you'd only see that under boost test.
Let us know!
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It seems to boost normally, it just tops off at 1350 or so, with requested being near 2400 during a WOT run.

If it were a boost leak, I would think it would be more inconsistent, or I would hear something, or the car wouldn't run right, or a code would be thrown. The car runs great, acceleration is smooth as silk, except for the lack of more than a minimal amount of boost.

If the wastegate were stuck open, it would spool up slowly. It spools up as quick as my old turbo did, it just maxes out at 1350 and holds. So that seems to point at the N75. I'll test it tomorrow.

 

Check the vac hose from the intake manifold to the dv, it could have been damaged when they were working on the turbo oulet pipe. (those vac lines will crack apart).

 

I pulled my N75 valve and tested it. It was clogged. After a few "suck-blow" cycles[:-] it freed up and it's working fine now.

I'll have to log again to see where my boost is, it seems a bit lower than what I remember stage 1+ being, but I haven't been on the highway yet to do a good run.