Volkswagen GTI Forums - My Fast GTi banner
1 - 4 of 4 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
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 F6

Rectangle Slope Plot Font Parallel


Once I reverted the settings back to stock, this is what I got
Rectangle Slope Plot Font Parallel


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.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #2 ·
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.

Rectangle Slope Plot Font Parallel


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 shit, 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?
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #4 ·
Were you able to figure this out? Would a broken diverter valve or wastegate cause something like this?

Sent from my SM-A505W using Tapatalk
yes, in my case it was an issue with my WMI spraying too much, after I changed the nozzle jet to a smaller one the issue was fixed
 
1 - 4 of 4 Posts
Top