Power loss - turbo not building boost as before!

[swansem]

Hey guys, I need some help here, my car is 08 GTI TFSI, recently I've been adding some mods to it but the main one being a water/meth kit. I have a Borg Warner K04 installed with Revo stage 3 software (have had it for almost 4 years now), my car would usually boost at peak 25-26 psi and hold around 23 psi, but ever since I installed the WMI and changed the settings using the SPS switch (upped the timing from 4 to 7) my car hasn't been boosting as before. Now, I don't know if it's just a coincidence that this happens at the same time I installed WMI, I also replaced the oem throttle body pipe with the CTS turbo one and replaced the intercooler hoses. I've checked every boost pipe/hose, make sure all the clamps are tighten up, visually at least I haven't been able to find any boost leak.
Other things I've done trying to fix the issue:
. Deleted PCV valve (replaced with oil catch can)
. Replaced DV valve with GFB DV +
. Checked for fault codes using VAGCOM - nothing comes up

I did some logging (requested vs actual boost) with the settings at B8 T7 F9



Once I reverted the settings back to stock, this is what I got



You can see how when the ECU is in stock actual matches up with specified easily and even passes it. So could it be the ECU map?

Any other ideas of what it could be???
I appreciate any help you guys could provide me, this issue has been driving me insane for quite some time now. Thanks.

[swansem]

here's another log I did the other day, notice how actual doesn't meet specified until really late in the RPMs(almost redline), it's like the turbo would be spooling really slow.


Also, it's odd that requested peak boost is only 1500 mbar (21.7 psi), for a stage 3 K04 that seems kinda low, like I said before I was hitting 25-26 psi normally.

Another thing I forgot to mention, at the beginning right after I finished installing all my mods, it was boosting 22-23 psi, coincidentally this happened right around the time weather in my area went to sh*t, it got really humid overnight so I let it pass thinking it was just due to the bad weather since it wasn’t that much difference from before (only like 2 psi less) but then..I decided to do some WOT pulls (to adjust timing for the WMI) and RIGHT AFTER I did this the boost went down from 23 psi to 19-20....

anyone got any idea what This could be?

[pudding]

I thought Revo Stage 3 was for hybrid turbos?

For a K04 you would usually go with their S3/Ed30 Stage 2+ software, which requests about 1.5-1.6 bar from memory (21-23ish psi)

Don't forget these ECUs measure boost in absolute, not gauge, so you need to deduct 1 bar (1000mb) from the requested and actual to get your gauge pressure.

When you say reverted back to stock, do you mean 'Stock mode' or Boost 1?

If you want stock boost, use B1, not 'Stock mode'.  Stock mode is nothing like stock, it's way more powerful.  Revo told me to use B1 for stock after many chats with them.

Anyway, the fact it's requesting 1500mb (8psi guage) points to a problem.   Stock K04 spikes 1.2 bar and holds 0.9 so that's a weird request.  I think you need to speak to Revo mate.

Before doing that, back the timing off to 5 and monitor timing pull with VCDS.  7 is on the high side, even for WMI. Remember you have put a K04 onto a K03 engine which has a higher static compression ('10.5' vs '9.8') so you won't be able to run K04 ignition advance.

The requested and actual boost are theoretical targets if everything is working as it should.  If the EGTs get too high and the ECU backs timing off, you won't get full boost.....hence try less timing to begin with.   Also try dropping the Fuel to 7 or 8.  Ideally you need to see 0.82ish lambda in boost for best power, which is around Fuel 8 from what I've seen.

Assuming all the hardware checks out, I'd suggest an email to Revo......but they will just tell you the same thing......check the hardware or back the settings off!

[swansem]

I thought Revo Stage 3 was for hybrid turbos?

For a K04 you would usually go with their S3/Ed30 Stage 2+ software, which requests about 1.5-1.6 bar from memory (21-23ish psi)

Don't forget these ECUs measure boost in absolute, not gauge, so you need to deduct 1 bar (1000mb) from the requested and actual to get your gauge pressure.

When you say reverted back to stock, do you mean 'Stock mode' or Boost 1?

If you want stock boost, use B1, not 'Stock mode'.  Stock mode is nothing like stock, it's way more powerful.  Revo told me to use B1 for stock after many chats with them.

Anyway, the fact it's requesting 1500mb (8psi guage) points to a problem.   Stock K04 spikes 1.2 bar and holds 0.9 so that's a weird request.  I think you need to speak to Revo mate.

Before doing that, back the timing off to 5 and monitor timing pull with VCDS.  7 is on the high side, even for WMI. Remember you have put a K04 onto a K03 engine which has a higher static compression ('10.5' vs '9.8') so you won't be able to run K04 ignition advance.

The requested and actual boost are theoretical targets if everything is working as it should.  If the EGTs get too high and the ECU backs timing off, you won't get full boost.....hence try less timing to begin with.   Also try dropping the Fuel to 7 or 8.  Ideally you need to see 0.82ish lambda in boost for best power, which is around Fuel 8 from what I've seen.

Assuming all the hardware checks out, I'd suggest an email to Revo......but they will just tell you the same thing......check the hardware or back the settings off!

thanks for the reply, I know it's not actually a "stage 3" but that's what REVO calls it when you swap to a K04, I have checked the settings since I do have the SPS+ switch and I've done tons of datalogging, my REVO settings appear to be fine, don't think it's the ECU map. I did however dropped the fuel to 7 as was advised by someone from REVO (put it at 6 originally but was getting too much ignition timing correction with Timing 7), now I have it at B8 T7 F7 and max timing correction I'm getting is -3 in only one cylinder on a really humid and hot day. My lambda values also seem to be fine (high .70s-low .80s under boost) which was also what REVO tech told me to strive for.

By reverting back to stock I meant stock mode. Also when I said 1500mb I was already deducting the atmospheric pressure, so it's actually 2500mb.

I'm more inclined to think this is an issue with either N75/WG Actuator. Someone on a different forum already advised me to test the resistance on the N75 as he had a similar issue before and it was that so I guess that's what I'm doing next, if it's not that then I'll check the WG, maybe it's just the nuts at the WGA's spring that needs to be tighten up? Will see...

Cheers! 

[pudding]

Yeah it could be either of those things.  Might be worth getting a new N75 anyway as I'm sure VW updated it at some point in the GTI's lifespan.  A pain in the arse to get to though!  Let us know if you solve it