Hey guys,

Now that my IDC issues are in check, I am tackling the boost curve. I have the familiar problem of the roller coaster boost curve.

I have ensured that error correction is not a factor and WGDC are constantly rising. I am not sure what else could cause this except for a leaking BOV.

I have boost leak tested to ~25psi using my compressor pressure gauge and didn't notice any significant noise. I don't mind doing another boost leak test if you guys think it's neccessary. Maybe I should crush it anyways

Can you guys think of another reason? Mivec?

Sorry for the crappy phone pic...

 

Image of WGDCs?

Make sure the last two columns are the same.

 

I'll get them to you after lunch...can't access laptop right now.

 

Are you just speaking of that first hump? In Derekste's car I was noticing that but he is on an MBC. Normally in the VIII / IX world this would be too high of a ramp rate on your WGDC near spool. Error correction can't do much about smoothing it, but leaving error correction off as you have can help tune out the initial "spike".

A text log might be more helpful.

 

Yeah, I'm talking about the initial hump. Though it is only a 1 psi or so dip, load changes more dramically and I can feel the dip while accelerating, kinda annoying.

I'll get some more data by EOD. I have limited access to data at work due to policy.

 

Tried taking a pic of the Boost tables in ECUFlash with my camera phone, but it's really unreadable...

Will post screenshots tonight along with CSV dump.

 

The stock BOV likes to let go after the 25 mark. You can hear it make this trailing flutter sound.

 

Are you using the stock boost control system? How could your reactive WGDC isn't maxed out at 100%? Boost pill?

 

Yep stock solenoids with boost pill.

 

I am not an ECU boost control expert, but I would imagine I could add in some passive solenoid action around the time of the dip right?

 

So I'm not familiar with the boost pill, but on cars without the boost pill, the stock map already uses 100% reactive WGDC at WOT. If it were my car, I would try to set reactive WGDC to 100% everywhere above 2500 RPMs (maybe set to 80% at 2000 rpms). Then try playing with your passive WGDC - most likely you will have to raise it just before it dips. However, I've noticed that some characteristics of the engine will cause natural dips that are pretty hard to tune around. Maybe someone else will have better ideas

 

Evoscan log included along with Pic of boost tuning..

 

Have you tried using the passive to tune it out?

- Bryan

 

Not yet Bryan, that's what I was thinking of doing, but wanted to ensure I was on the right track...

I'll play around with passive tonight.

 

increase reactive duty cycles in the backwards "hump" area. its that easy.