openecu.org

Did that. No change

Try a manual boost controller, just for testing.

To do what? disable boost?

west_minist wrote:To do what? disable boost?

Disable? No.

Use it to try to smooth out the boost curve, and see if the dip in power goes away. The current 3psi drop in boost @ 3.5k rpm definitely isn't helping matters... but, at the same time, neither is the drop in timing at 3400 or the lack of power (too much timing?) from 3500-4000.

There isn't any drop of 3psi in boost at 3.5k?? unless you mean 3 degrees of timing dip...

Could it be running rich with the open/loop transition?

engr wrote:There isn't any drop of 3psi in boost at 3.5k??

Looks like manifold absolute pressure drops from 29.5 to 26.5 right around 3500 to me...

This thread is getting unnecessary long. I'm just too tired from Telecom.

Thats the default boost curve on a wrx 2002-2003. Check the wg setting in stock roms. It does not cause problems in the torque curve.

If you look @ the 17psi log, you will see no boost drops.

The car produce less power almost @ full spool. Its like a leakage or something. It is like pressure builds and lets go a bit.

I feel it has to be around the head.

Please remember, in the 17psi log, The turbo is have good boost pressure. So we need to think of what could be affecting the tq, but turbo still functioning perfect. Ah. My head now want to hurt.

Good luck guys. I will check in later.

How is 17psi "stock" boost pressure again?... please explain.

...........


I posted stock graphs and tune graphs.

Let me replace that abs. psi graph.

Here we go.

Could a leakage around the turbo cause this behaviour?

With changes to the exhaust on the stock map the car may be overshooting the targets in the map. The ecu will use turbo dynamics to try and correct this by reducing wastegate duties but will most likely overdo it resulting in lower than target boost. It then tries to compensate by increasing them but it overshoots again, so it reduces duties again etc. This can produce a boost curve like the one just posted. I have had this on my car and you can feel it happening as well as see it on the boost gauge or in logs.

Have you checked to see if the car is hitting the boost targets exactly or exceeding them ? With the stock solenoid the wastegate duties may need reducing considerably to adjust for the higher flowing exhaust. At 2.3 bar the max duties were reduced from 90 to 55 to correct the overboost. This was from fitting a 3" bellmouth downpipe that tapers to 2.5" and connects to 2.5" pipework with no boxes except the rear muffler.

This curve is almost similsr to others I have seen base on the wg.

Again, it exists all throughout tunes. So that is not the case.

the car hits target boost on stock map.. it was fairly stable and unfruitful, the power dip was still there, but albeit smaller dip..


would slipping tranny cause this as west_minist says?

west_minist wrote:This curve is almost similsr to others I have seen base on the wg.

Again, it exists all throughout tunes. So that is not the case.

If I understand you correctly, it sounds like you have tightened the wastegate arm as tight as it would go? If that is the case, then it is possible you would get a boost spike, even on the stock ROM and every other ROM you threw on there.

The graph you just posted looks like a classic boost spike . Notice how it peaks up and then drops really fast, jumps back up but less than before, then down and then you can see it do this again, but just barely. Not sure what ROM you have, but to rule this out, you could take the turbo dynamics burst's (or intergral positive/negative's) highest and lowest values and set them to 0 and re-log.