Help - Am I overboosting

Hi guys,
I recently straight piped my exhaust, and I noticed the car boosts a lot easier (I have a boost gauge), but I noticed that i'm making about 25 psi according to the gauge. I just did some vagcom logging and found out that peak actual map is 2550 mbar. I have no CEL or overboost codes. Do you guys think this is bad? or am I still in the clear?
Thanks

You are overboosting. You are probably just under the threshold time-wise for the code to trigger.

Disconnect the vacuum hose (and plug it) to the actuator and see if it still looks that way. The vane lever or actuator rod might be stuck.
Check the actuator with a mity vac and see if it can move full stroke (~5/16" at the end of the lever) and how much vacuum it takes to draw the vane lever to the stop screw. Should start to move about 3-4"hg and end about 18"hg at the stop screw. If not, and the lever can move full stroke, then try lengthening the actuator rod until you get that reading. The N75 valve duty cycle looks to be running at around 100% when it is trying to dump boost. Much more than 80% means that it is struggling to do that.

Also, make sure that the vacuum relief hose from the N75 valve to the air box is not restricted.

You're going to need to lengthen the VNT actuator a few turns to compensate for lack of catalytic converter.

2550mbar is the upper limit that the stock MAP will ever read. You will get MAP sensor overvoltage codes soon.

OK thanks guys. I know a couple months ago I checked the actuator and it was bang on with full range of motion. I'll have to check it again

ace123655 said:

OK thanks guys. I know a couple months ago I checked the actuator and it was bang on with full range of motion. I'll have to check it again

Click to expand...

You will need to actually be more than the 'bang on' settings for catalytic delete. The reduced backpressure causes more difficult boost control and the turbo boost spikes much easier.
Either lengthen the rod by trial and error, or do it out of the tune.

Enabled said:

You will need to actually be more than the 'bang on' settings for catalytic delete. The reduced backpressure causes more difficult boost control and the turbo boost spikes much easier.
Either lengthen the rod by trial and error, or do it out of the tune.

Click to expand...

Good to know...

Greeting to all,

Thank you all of you for all replies and solutions offered so far. Now i have a big problem, i face with a lot of overboost, spikes that killing the turbo especially in the first gears, even when the car was stock. The problem is a little bit complicated. The car was remapped last year, and it works very well, until a few days ago, when it became very lazy. First of all i checked the vacuum hoses, every pipe. Then i checked the actuator, the MAF, (switching with another MAF), the n75, trying 3 pieces of valves. I also checked the turbo pipes to the intercooler, and there's no leakage. Finally i discovered the n18 with no vacuum on it. I checked with a multimeter the voltage at the plug and it shows around 12v. Also here i try another valve. It is possible that the n18 be cancelled from ECU, when the car was remapped, and that's why there's no vacuum? I will return with a log if it helps. This car is drive me crazy, the boost gauge it shows around 2 bar in 2-nd gear. I don't know what can i do. Please help.

Is there no vacuum to the N18 or from the N18?
The N18 is a pressure converter for exhaust gases.
The N75 controls boost
http://uk-mkivs.net/topic/34834-vnt-tdi-turbo-how-to-adjust-actuator-cure-boost-problems/

What is the engine code?
You list your car as a 1.9L PD and here, in North America, the EGR on the PD (BEW code) is a motor driven valve, not vacuum. Is it different there?
A log and maybe a picture of the set up would help.

JETaah said:

What is the engine code?
You list your car as a 1.9L PD and here, in North America, the EGR on the PD (BEW code) is a motor driven valve, not vacuum. Is it different there?
A log and maybe a picture of the set up would help.

Click to expand...

is an ATD code. PD from "Pumpe Düse" engine.

BobnOH said:

Is there no vacuum to the N18 or from the N18?
The N18 is a pressure converter for exhaust gases.
The N75 controls boost
http://uk-mkivs.net/topic/34834-vnt-tdi-turbo-how-to-adjust-actuator-cure-boost-problems/

Click to expand...

No vacuum from N18.

Hi there,

Sorry for late. I solved the problem few days ago.
1) The main problem was a vacuum leak, probably around n18 valve. Indeed there was no vacuum from n18, as long as the EGR i canceled from ECU.
2) After a few logs i saw another problem, the MAF. At idle the value was around 200 mg/str. With the new MAF the value is around 400. After that, the car goes very well, but it was still a little bit overboosting.
3) Then, it decided to lengthen the rod. Now the rod has 9 spirals instead of 7. At full load the max pressure is 1.4 bar.
4) Finally I removed the n18 from the vacuum line, but i kept the n239, because is a little bit shuddering without n239 when i turn off the engine.


I attached the new vacuum line.
I don't the have the logs, because i forgot to demand them.


http://postimg.org/image/svlgektx9/