Golf Gti Mk5 k04 - ebays finest components - overboosting on partial throttle

Hi all,

help and insight please on a golf 5 gti dsg with a chinacharger k04, oem equivalent diverter valve, twintercooler, ebay intake, autotech hpfp upgrade, s3 injectors, full exhaust (3inch downpipe and no cats)

Car runs like a raped ape on wot, peak boost in midrange is 25/6 psi, tapering to 17psi at redline, actual lambda is spot on, requested and actual fuel pressure follow perfectly, no knock / misfire events on WOT however on partial throttle it will over boost in the midrange and trigger over boost code, it will run past 30 psi in the midrange with a light throttle, sub 30% pedal angle, but it obviously trips the boost cut and the ecu switches the boost off until a key off / on cycle resets it

I am looking for some guidance on solving this
I think the fault sits, in either the PR ratio limit table and/or the dbw throttle desired pressure ratio in boost or is this a maximum desired load issue ? I am a bit lost in the math's now of getting this to line "back up" from lots of changes made

I have made loads of changes and the attached file is by no means the correct one, just getting a bit lost in this and feeling like tail chasing is going and its time to pause / engage and think about this, any and all feedback welcomed or if anyone knows the maths needed to get those tables to line back up it will be great

or is this potentially a hardware issue with the chinacharger and its associated N75 valve it came with ? or hardware issue else where ?

Quote:

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Originally Posted by 3barboost

Hi all,

help and insight please on a golf 5 gti dsg with a chinacharger k04, oem equivalent diverter valve, twintercooler, ebay intake, autotech hpfp upgrade, s3 injectors, full exhaust (3inch downpipe and no cats)

Car runs like a raped ape on wot, peak boost in midrange is 25/6 psi, tapering to 17psi at redline, actual lambda is spot on, requested and actual fuel pressure follow perfectly, no knock / misfire events on WOT however on partial throttle it will over boost in the midrange and trigger over boost code, it will run past 30 psi in the midrange with a light throttle, sub 30% pedal angle, but it obviously trips the boost cut and the ecu switches the boost off until a key off / on cycle resets it

I am looking for some guidance on solving this
I think the fault sits, in either the PR ratio limit table and/or the dbw throttle desired pressure ratio in boost or is this a maximum desired load issue ? I am a bit lost in the math's now of getting this to line "back up" from lots of changes made

I have made loads of changes and the attached file is by no means the correct one, just getting a bit lost in this and feeling like tail chasing is going and its time to pause / engage and think about this, any and all feedback welcomed or if anyone knows the maths needed to get those tables to line back up it will be great

or is this potentially a hardware issue with the chinacharger and its associated N75 valve it came with ? or hardware issue else where ?

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logs and stock tune would be helpful, I can offer some help once I see those :)

hi, can do logs, not sure if i can get the stock tune, let me look for it - the car had been previously tuned

what I have seen in comparing this file with other vw ones, is in this definition there is no max overboost value exposed, I dont really want to go switching the code off as that is a bit cowboy

without logs i would look at the following...

you should set [ECM] 14803 - Compressor Overspeed PR Limit to 3.98 on the whole map and then tune boost using [ECM] 34893 - Maximum Desired Load and varients

also you need to tweak [ECM] 32900 - Optimum Engine Torque to request 100% torque as well as the inverse load axis of this map to represent what your load will be at the new torque request