After putting some K16 Hybrids on my TT
(2005 with only 36.000miles on it)
i realized that the original WGs are to soft to hit
the Boostlevel I want.
I had an solid FVD Tune and it works great with the hybrids, but only capable of boosting 1,1bar because of the original WG Springs.
After installing 1bar WG Springs I hit 1.3bar max Boost,
but now there are some "Waves" that feels like timing retard but its only
in actual Boost via Duramertic Log.

The tuner told me, that the Tune ist programmed for the 1bar WGs,
and there must be some mechanical problems.
I checked the WGs... ok
WG set to 0,6bar start open... ok
Sycro WGs... ok
Pressure Test... ok

Since the Problem starts, the following parts were changed:
MAF new
N75 new
710N new
Sparks (NGK Iridium) new

Parts installed:
k16/24 Ext. Tip.....
997GT2RS ICs
997TT injektors (650ccm)
HJS 100cell PE-Cats
997GT2 Exhaust

Any Ideas?

Phil

 

your datalog doesnt show rpm and exact boost....

base boost setting for 1bar wastegates with 0,6 bar is way to low....0,8bar preload is minimum

your boost waving are only below 3000rpm under full throttle and in high gears?

 

The Waves are between 3800 and 5000U/min in high gears as shown in the log. The higher the more the waves are present.
The Log is in 5th gear.

Phil

 

i would adjust first the wastegates to open at 0,8 bar (if its 1 bar wg)

maybe not enough preload at the wastegates... check that the gates open and close smooth .... and close with the correct preload

boost leak? check it..... that is what good members at the forum are always saying

do you only see the wave at the datalog ore do you feel it

 

I can feel it....

Phil

 

similar thing happens to me. I have a 996 Turbo S 2005 MY and i get spikes of boost up to 1 bar, i lift off the gas and press it again and then boost goes up to 0,6
The car has uprated WGs and a roof exuast with stock ECU and stock k24s
It has covered only 20k miles in total and its in like new condition

 

set the WGS to start to open at 14 psi- BUT only if you have a tune for after market WGS.... you need a hand pump to set them up correctly...
how did you do a pressure test? you need to do it from the lower boost hoses and pressure test it to lets say 20 psi and it must hold for 30 seconds...
I bet between both of those things I mentioned you will find your issue... this is easy you r just doing something wrong and or the way you put it together is not right.... not to mention the tune should be set up for stronger Wgs...

 

The WGs are synchrone set by handpump to 9 PSI.
Made pressure test from lower boost hoses at 18 PSI. -> No leaks.
-> Have to check the Tune again?

Another Question:
If I set the WGs to 14PSI, what about boost pressure at partial trottle?
At the moment at partial trottle setpoint boost claims 970mBar while boost pressure sensor shows 1.200-1.300mBar in Durametric
Because of the WGs can´t open with that small amount of pressure over the WG-control-lines / N75??

 

You basically answered the question.
You have a tune for stock wgs and your trying to manipulate 1 bar wgs ( I'm guessing that's what you put on) to work properly thruout the rpm band.
You will face issues as you are.
Either put back the oem wgs or get a tune for after market wgs. Thats the right way of doing it and you will not have any inconsistent boost issues.
Keep it simple. That's what's going on. Your current tune had the n75 maxed out at 95% but you have after market wgs. You will over boost at wot and have a laggy car down low.
Again , assuming you have 1 bar wgs or so.
Markski

 

I hope your running injectors at 1.3 bars!!!!

 

Yes, running 997tt 650ccm inj. No problem with lean AFR.
Quite the opposite, its a little bit rich.

Have found a log with N75.
I dont think its maxed out.... looks like it doesnt match the needs.
Am I wrong?

Phil

 

data logs from durametric my friend... not graphs you make please...
your not understanding what Im saying about the n75 being maxed out or not... its not.. its where the values are set...

 

Excuse me Markski,

enclosed now the logs of that testrun.

Phil

 

I was right.
Notice n75 is at 96%. That max setting. It's a tune for oem wgs not 1 bar. Now u can play with it and make it work better but don't complain why your not happy.
It's that simple
Usually 1 bar wgs are set to open 14 psi and the duty cycle is somewhere in the low 80s or high 70s at full throttle. And that has nothing to do with part throttle ( that's another story )

Markski

 

Thanks Markski for the open words!
Tuner told me that it is for 1bar WGs so this was the last point on the list.

Just thinking:
How is it possible to change the n75 by Software to be more open than 96%?
96% means that all pressure goes to the WGs.
That confuses me... How can it be more open?

Phil