[pyrax]

Hey people of e90 post!

So i just got my custom tune from Justin @ TwistedTuning and while I was getting logs for the car, I noticed under load, I kept getting the 2ABC and 3100 codes and was put into limp mode. The codes go away after being cleared, but come back after I hit WOT.

I think I am overboosting and thats what's causing the limp mode and codes. I have boost max set to 18psi and the boost safety setting set to 20pst (I have the 2.5 bar sensor), but according to my logs, Im hitting ~ +21 psi.

Before people tell me to check my wastegate plumbing and such here is some background info:
- My mac solenoid works, I hear the clicks when testing
- I have 2 Tial wastegates with 10psi springs each.
- Wastegate vacuum line plumbing is correct, as I had an issue where I wasn't hitting boost but fixed it via the lines.
- I don't have a vacuum fitting on my turbo so I made that line go to the stock vacuum location and plugged the other tube (the 2 tubes that go across the valve cover)

Here are the specifics of the build:
- Borg Warner S366 Turbo
- 2 tial wastegates
- knock-off hks bov (Yes i know, I'll get it replaced soon ): )
- Walbro 255 LPFP
- 5in Intercooler
- VSFR Chargepipe
- STOCK 2.5BAR MAP SENSOR


I'll attach the most recent log I have of the problem occurring. Any and all help will be appreciated. Thank you everyone!

[Ozzie335i]

Send the info to Justin for advice.

[pyrax]

Originally Posted by Ozzie335i

Send the info to Justin for advice.

I already did that about a week ago. He hasnt gotten back to me yet so I thought i'd get some alternative input from the forums too while i wait (:

[pyrax]

bumpp pls help someone haha

[Aceway]

Jb4? There's a firmware you need to download for single turbo, not sure if you've done that.

[pyrax]

Originally Posted by Aceway

Jb4? There's a firmware you need to download for single turbo, not sure if you've done that.

yes jb4. Its a custom tune from Justin @ TwistedTuning so im using his single turbo backend flash

[Aceway]

Originally Posted by pyrax

yes jb4. Its a custom tune from Justin @ TwistedTuning so im using his single turbo backend flash

Ok but did you download the firmware? It's step 2 on the JB4 single turbo guide.

[pyrax]

Originally Posted by Aceway

Ok but did you download the firmware? It's step 2 on the JB4 single turbo guide.

Yes i have the single turbo firmware. Im on the beta v139. I had stable v136 before but updated

[pyrax]

SOLUTION: After researching for days. I decided to try a new vacuum source. I hooked up the line to the meth plug in my charge pipe and now all is good. I originally was using the OEM vacuum source for the twin turbos with one line capped off. This seemed to be my problem. I didnt have a nipple tapped on my turbo so and I didnt want to tap one myself. If anyone else is having a similar problem, try using the meth plug as your vacuum source.

PS: Another sign your vacuum source is lacking is your target boost will be significantly lower than your actual boost pressure (:

[relative4]

Originally Posted by pyrax

SOLUTION: After researching for days. I decided to try a new vacuum source. I hooked up the line to the meth plug in my charge pipe and now all is good. I originally was using the OEM vacuum source for the twin turbos with one line capped off. This seemed to be my problem. I didnt have a nipple tapped on my turbo so and I didnt want to tap one myself. If anyone else is having a similar problem, try using the meth plug as your vacuum source.

PS: Another sign your vacuum source is lacking is your target boost will be significantly lower than your actual boost pressure (:

Do what? You're using the charge pipe as a vacuum source? Well, that'll prevent overboost for sure. As soon as the turbo starts spooling, you'll get pressure instead of vacuum to the wastegate actuator and immediately reopen the wastegate.
At this point, I highly recommend taking the car to someone experienced with modifying N54 setups, and then getting it re-tuned.

[pyrax]

Originally Posted by relative4

Do what? You're using the charge pipe as a vacuum source? Well, that'll prevent overboost for sure. As soon as the turbo starts spooling, you'll get pressure instead of vacuum to the wastegate actuator and immediately reopen the wastegate.
At this point, I highly recommend taking the car to someone experienced with modifying N54 setups, and then getting it re-tuned.

many other people have done the same setup with single turbo. I personally logged by runs too and can confirm the wastegates open and control boost at the desired levels. I needed a positive pressure only source. That's what I meant to say, sorry for the confusion.