I just check your thread again.... you say you have after market actuators running stock X50 program? if so why? what makes you think the ecu will not "freak out"? it will.... the TB is closing because there is a boost limiter map... and your exceeding the values running too much boost... usually the stock map is at 1.3 bar on a fully warm car...
your running to much boost... am I correct to say that you are on X50 program?

 

Thanks for all feedback during this process!

Timeline went as follows:

- Mounted slightly used K24. Seller says they are 0.8bar wastegates, or so I remember at least.
- Put car on dyno - big misfire.
- Tried different steps on the tune to make it work. No luck. Decided I have to troubleshoot hardware b/c it's not possible to tune it whatever tuner did with it to make it work. Put in stock X50 file just to troubleshoot.
- Changed sparkplugs and coils. Car runs better - no big misfire anymore.
- Done some logs. Now it's clear the wastegates are not at 0.8 bar.

The troubleshoot is the only reason the car has stock X50 flash at the moment, and that I thought the wastegates were set to 0.8bar.

Now that I know, the car will go back on the dyno as soon as I checked that the wastegate actuators are balanced. Monday I hope.

 

Ok I see now... good luck....
mark

 

Adjusted the wastegates by simple tools and car runs much better.

WAS: Each wastegate started to released at 15psi and cracked open at 16 psi. It took 22psi to get near half open. Hm.

NOW: Wastegates start to release at 11psi and crack open at 12psi.

LOG: Tried appr 10 times to get a good log, but every time Durametric would crash. I reduced the sample rate to minimum and removed O2-sensor values and in the end I snuck in a half-a** run to 5000 rpm just so I could hit save before the program crashed again. It would run for minutes, but as soon as I did a hard pull it would end up crashing just as I coasted down to save the file.

At least it seems now the throttle body stays open at this level w/o wastegates being out of control.

Imo actual boost seems pretty delayed vs setpoint but maybe it's normal?

 

Your tuner need to change the pd/factor, if set to low you will get this result.

 

Thx!

+ He will change a lot of things.

This graph was taken with a bone stock X50 flash (no edits made yet), however actuators were upgraded.

 

Did you ever find a solution to this?

 

I had a similar problem at 28k miles. It ran normal with a K16 tune, but shuddered on boost when I flashed it. Just had the plugs changed, and they were hammered.

I haven't reflashed yet, though. Will update when i have.

 

I have a 2004 996 x50 4/04 build date, Ruf and notice that when I use CA 91 octane (CA premium) the car runs very different, 491 HP, multiple runs with telemetry/weight calculated sorry not Dyno, no all wheel drive dyno's around, after filling with 97 or 105 Octane (97 seems to do it), and about 5 starts and drives, it feels like a different car, even the exhaust note sounds very different, and it is at 592 on a one mile telemetry run, and definitely feels much faster and gets up there much quicker, could it just be the knock sensor turning off, and the ECU adjusting?, or is there more to it. no one ever seems to explain exactly what causes the huge difference, how much advance is changed/retarded by this knock control, there is a tag on engine lid that says knock sensor was added, even seems that the 1.3 bar appears quicker, people that see my car daily can even tell when I have the good gas in it just from the sound.
Anyone have insight on this? Is it just the Octane, and knock sensor? How much advance does this knock sensor actually back off?