Recently I built my MY2012 Octy 2 vrs tsi dsg into a 4wd haldex k04 project. I will do a write up on the build but for now I'm facing an issue with my k04 setup.

On the engine I used:

• Borg Warner K04-64 with a modified outlet (to clear the TSI block) (bought it used with 1000km).

• Intercooler upgrade (2.4" thick core) LINK

• 2.5" throttle pipe (from intercooler to throttle valve) LINK.

• EA113 DV relocation kit (like an S3 8p). LINK

• High flow Downpipe with sports cat. LINK

• OEM intake and airfilter.

• OEM backbox.

I'm running a Revlimit ST3 K04 ECU tune and ST3 DSG tune.

The ECU tune still needs tweaking but my tuner says I need to add preload to the wastegate to achieve 2.5bar of boost (absolute). I have tighten it quite a bit (12 turns?) and barely managed to raise it from about 2.1 to 2.3 bar.

I'm starting to get boost surge and turbo flutter at 2.5 -3k rpm at mid throttle which makes me feel the WG might be a getting too tight. I think this can be tuned out with the n75.

Tightening the WG is quite a job now with the transfer box in the way. Is there a way to diagnose a leak or too loose WG from logs?

Here are some pulls and some "surges" I Iogged:

https://datazap.me/u/etche/boost-logs?log=0&data=0-7-8-9&solo=7&fbclid=IwY2xjawMcOyhleHRuA2FlbQIxMABicmlkETE4cEZrc1duM2trUFRldTh3AR6uaK7sT0yZ1tKUSRPYvSZNlvGf_6gPd36vHobk3Nby3X2YltXyLrrRsbzM0w_aem_oJVWWY_IGD2O2xSP_t0F6w

When surging timing advance goes negative!

Just to close this topic: I ended up tightening the WG.

How to on a 4WD car (with bevel transfer box in place):

• Remove airbox, battery and battery tray as if you were replacing a box mount.

• With a long 90degree pick remove the safety lock from WG nuts (it will fly away. try to find it to refit it later).

• With a deep 10mm socket (and a couple of extensions) loosen the nut closest to the battery. I had to file down the socket tip as it wouldn't seat properly on the nut.

• With your hand turn the other nut towards the WG (1 turn ~ 0.1 bar).

• Now tighten the 1st nut with the socket.

• With a short 10mm open wrench (or bend one) hold the inner nut while you tighten the outer with the socket.

• Refit lock (I lost mine).

• Refit battery tray, battery, airbox and plug MAF.

This is the easiest way I found to do it. Trying to access it from underneath seemed impossible as there is the transfer box in place now.

Some references that helped me:

• https://motozaperformance.com/wp-content/uploads/2018/10/WastegateAdjustment20T.pdf

• https://www.audizine.com/forum/showthread.php/420536-Wastegate-Adjustment

Regarding surge: seems pretty common on boosted K04. I'm still getting 15ish retard on ignition which doesn't seem to be cylinder retardation related at all. It happens when actual boost is about 200mbar over specified.

2.5 bar reached!

Ignition retard when surging. Typically at around 3k rpm and mid throttle.

Sometimes followed by flutter noises when upshifting.

WG actuator with lock in place. Seen from battery side.