OVERBOOSTING PROBLEM

[JOEL]

Hi guys,

Car is R32 with RB25 S2 engine, link g4x ecu, I was wondering if anyone can help me out as to why my car is over boosting.

Was tuned on dyno, all was fine for a few months, upgraded turbo to a slightly slightly larger one, waiting for another tune now.

It's meant to only reach 1.2 bar, but its going up to 1.5 and hitting cut.

Just want to confirm it is not something mechanical before I take it in for a proper re-tune.

Things I've done:
- Recorded the waste gate while driving (to make sure its opening)

- Ground out my bell mouth dump pipe, to make sure the flap isn't getting caught on anything, it opens fully.

- Went over vacuum lines, replaced some, all were fine.

 

Ive attached the log here, also the tune file.

You can see at around 2:30 where it happens.

Let me know if you see anything,

Thanks heaps

overboosting.llgx JOEL.pclx

[Adamw]

It appears that map has been changed since the log was done.  The log shows there was 74-54% duty cycle going to the wastegate, but the map now has zeros in it.  

[JOEL]

Sorry, may  have uploaded wrong file.

Please see attached @Adamw, Thanks heaps

LATEST.pclx

[Adamw]

Yeah thats more like it.  

Zero out the watsegate DC table and confirm it controls a spreing pressure.  This table will have to be completely re-tuned when you change anything turbo related.

[JOEL]

Still seem to be overboosting, spring is a 14psi spring,

I've set the map limit to 255 to fix the cutting temporarily but its still overboosting hard which is a worry. Its boosting to approx 20.8 psi now, feels fast as fuck but its just not right lol

Hopefully the enging isn't going lean. My tuner told me it was tuned to around 11 afr for safety so I doubt its going lean

[Adamw]

If it overboosts with the wastegate DC table set to zero then it is not ecu related.   It could only be either plumbing or mechanical.

[JOEL]

3 hours ago, Adamw said:

If it overboosts with the wastegate DC table set to zero then it is not ecu related.   It could only be either plumbing or mechanical.

Thanks Adam, I'll look at some different options of routing the vacuum lines and go from there.