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19' Q50
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Discussion Starter · #1 · (Edited)
I didn't found anyone in the forum talking about this issue so...
H E L P
2019 q50 (300hp)
modification list:
bms heat exchanger
aem meth injection kit
ams intakes
3"full downpipe
3"exhaust no cats or whatsoever restrictions
currently ecutek tuned by mastuning (local tuning garage)
_
I have an issue with my car (boost creep) on ((both)) turbos when full throttle-> boost cut then goes into limp mode after 1 or 2 pulls even though the wastegate set to minimum 20% the boost still hits +25psi
also 2 codes appeared several times after full throttle
P0234
P1334
IMG_20201117_000902.jpg

car is new, only at 12k miles, didn't run into any issues before...
from my digging on other forums and articles I came up with 4 possible causes..
1- possible leak in the system?
from a superficial look all the hoses looks intact, no major leak from them,, where could it be?

2- waste gate issue.. actuator stuck maybe?
no codes regarding boost controller sensors,, do I need to port the wastegate passage since ours is too small?

3- faulty sensors? MAF?
I dunno about that I didnt touch any, maf installed properly, and the car is new, they seem reading fine :)

4- 3" Fdp and straight pipes causes both turbos to spool uncontrollably?
maybe I need to add more backpressure?
____

what should I check first, second... etc
what did I miss?!! 馃槶
 

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Newport, Oregon
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My guess would be #4. A catless 3" downpipe and exhaust with no mufflers could induce boost creep easily. You've added CAIs also to improve airflow through the engine. It is a mechanical limitation of the wastegate that occurs from running a catless exhaust and intakes combined with cold temperatures (typically below 40* F). Boost creep is exaggerated with every restriction that is removed from the exhaust. Boost creep is caused from the lack of back pressure and the physical wastegate being too small to bypass all the exhaust gas.

Since the exhaust can鈥檛 fit through the wastegate, it is forced through the turbine wheel which causes the boost to uncontrollably rise. I'd get back with your tuner and see if there is anything he can do but boost creep typically can't be tuned out. You may find you need to install cats or mufflers to increase your backpressure. 25 PSI is dangerous to a VR30.
 

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Newport, Oregon
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19' Q50
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Discussion Starter · #5 ·
Ok I its more clear now, thanks @IridiumRS400 ,, but still I found it illogical that there are many vr30 with full 3" dp and aftermarket highflow cai and no one of them ran into this issue before? That means I can install for ex.2 high flow cats and 2 mufflers and problem solved? :unsure:
Also I didn't fully understand the egr code can anyone explains it in a simple words or how its related to this boost creep:unsure:
96932
 

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Ok I its more clear now, but still I found it illogical that there are many vr30 with full 3" dp and aftermarket highflow cai and no one of them ran into this issue before?

Also I didn't fully understand the egr code can anyone explains it in a simple words or how its related to this boost creep:unsure:
View attachment 96932
The VR30 doesn't have an EGRTP, nor an EGR, so you might be misinterpreting the P1334 code. The takeaway is your tuner needs to dial-down the boost, which includes allocating for boost spikes, boost creep, etc., despite having meth addition. The 3" Full DPs are fine, as long as the boost limit is adjusted.

The stock Garrett turbos like to run a peak boost of 19-21 psi., which is at the top of their efficiency range. Any more than that, and it's more heat than boost.
 
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Newport, Oregon
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Ok I its more clear now, thanks @IridiumRS400 ,, but still I found it illogical that there are many vr30 with full 3" dp and aftermarket highflow cai and no one of them ran into this issue before? That means I can install for ex.2 high flow cats and 2 mufflers and problem solved? :unsure:
Also I didn't fully understand the egr code can anyone explains it in a simple words or how its related to this boost creep:unsure:
View attachment 96932
I'm not sure where you got that DTC definition but it's not for this car.

P0234 - Bank 1 (passenger side) boost sensor is detecting an excessively high turbocharger boost.
P1334 - Bank 2 (driver side) boost sensor is detecting an excessively high turbocharger boost.

Your DP/CBE/CAI combination makes your engine more susceptible to boost creep and your tuner didn't take that into account if you're seeing 25 PSI boost spikes. You need to have your tuner readjust your tune to compensate before you damage your engine.
 

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19' Q50
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Discussion Starter · #10 · (Edited)
I'm not sure where you got that DTC definition but it's not for this car.

P0234 - Bank 1 (passenger side) boost sensor is detecting an excessively high turbocharger boost.
P1334 - Bank 2 (driver side) boost sensor is detecting an excessively high turbocharger boost.

Your DP/CBE/CAI combination makes your engine more susceptible to boost creep and your tuner didn't take that into account if you're seeing 25 PSI boost spikes. You need to have your tuner readjust your tune to compensate before you damage your engine.
The tuner told me that he adjusted the wastegate to a minimum value (20%) and still saw a major boost rise,, "out of control" he said, what else can he adjust to lower the boost other than wg?
,,, thats why I considered a leak in the system and/or my cai dp cbe combination being with minimum restrictions as possible,, any suggestions on how to increase back pressure a little bit?
Also where can I search for vr30 DTCs,, couldn't find it anywhere
 

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I am so tired of hearing people say that FDPs and exhaust cause of of control boost creep. Your tuner should have zero issue controlling boost and if he can't then he shouldn't be your tuner. If there is a mechanical issue, your tuner should be able to troubleshoot that.
 

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SW New Hampshire
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Who is your tuner? This should be fairly easy to tune out by lowering the target boost at higher RPM.

If the desired boost is 20 psi at 6K and the target boost is 20 psi but you are getting 24 psi, lower the target psi until you get the desired psi. So the "target" psi may need to be 18 psi at the higher RPM's to actually get your desired 20 psi.

AMS, and Specialty Z are very competent VR EcuTec tuners.

I got an overly agressive tune that felt wonderful, but over boosted and put me in limp mode. Got a corrected map later that day.

With my Pure Stage 2 turbos I get 22 PSI max with my AMS tune.
 
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