I have been using a GM solenoid to control boost recently and I noticed a couple things.

I can hear my wastegate opening and closing and the boost fluctuates about 1psi as it does that. I am not using pills of any kind.

Has anyone experienced this? It makes the car feel wavy at full throttle.
Would pills help.

 

Boost logs would be helpful.

You are holding 295 load at 7,000 rpm?

 

i am also having the same problem sounds like the wastegate is fluttering and you can feel it slightly

 

I think your Load target is way off. Your BCLO is set @ 160 and your BDEL is @ 150 @ peak boost/torque. That means that your target load is 310. Are you hitting 310 when logging the 2byte load?

 

yes my target load plus offset very closely matches my load. I am on meth running 26 PSI.

Its odd, sometimes the logs show the psi wavering, and sometimes they dont.

Let me find a log that shows what I am talking about.

 

Have you logged WGDC as well?

 

Here is a log and a screen shot of it in DLL.

Boost, WGDC, and 2byte load are logged.
The Load is offset by 100 so it is easier to graph. Add 100 to the load values you see on the DLL graph.

Also I just realized the maps posted in the first post where what I am running now, this log was done with boost offset set at 140 NOT 160.

The tune is not finished so please no comments on what the timing and AFR look like.

This is with a GM solenoid.

Boost stays kinda flat but load, and even Injector Duty Cycle goes up and down

LOG

 

I didn't think that you could go over 100 in MWGDC, I figured any higher wouldn't matter
I have noticed just by watching the boost gauge that mine will sometimes peak and then drop and then raise slightly. I havn't logged my boost yet though, I can't get my zeitronix logger to log simultaniously with evoscan(anybody know how to log both programs at the same time?)
I would think it is all in how you set up your MWGDC numbers, but what do I know I'm still learning this whole gm solenoid thingy anyways
ed

 

Does it do this with the TBEC table set to 0 as well? If it doesn't then your BCLO+BDEL is off. If it does, then something mechanical is at fault.

 

you could try turning down your correction. I have mine at 8 / -8 on either end of the correction table.

8
8
8
8
6.5
4.5
3.5
2
0
-1.5
-3.5
-5
-6.5
-8
-8
-8
-8

 

I will try turning down TBEC and also setting it to zero to see if it makes a difference.

I might not get a chance until this weekend but I will post up the results when I can test it.

Thanks for the help guys.

 

I would reduce the "Boost Desired Engine Load" @ 3000 on your program. Your log indicated WGDC was from 85 - 81 between 3K and 3.5K RPM (where it varied the most). It was consistant from 3500 RPM on....

Also, I would fine tune the max WGDC... It seems that you never hit more than 85 but you have 90ish on there...

I'd put correction with higher number like (you could say lower number mathmatically) like -20 for ECU to adjust quickly if you see more than 15% difference in postive boost........

There is no answer but for you to log and adjust the setting closer to what you want! I normally use the "Max Desired Engine Load" last to fine tune to boost curve and MAX WGDC to minimize the spikes or full boost under partical throattle....

Again, it is entirely up to you...

 

The wavyness that your seeing could be the ECU applying correction. Allowing more correction is likely to worsen the jaggedness. Alot of people 0 out the correction map and tune the wastegate duty to be close to their BDEL + offset and then turn back on error correction with lower numbers to allow the ECU to correct to differing enviroments / gears.

 

ya you cant have more than %100 dutcy cycle. Dutcy cycle by definition is amount % time ON to OFF. a signal say 2ms with %50 Dutcy cycle would mean 1ms ON and 1 ms OFF. with %100 it would mean 2ms ON and %0 OFF.
so you can have and output bigger than the input of 2ms.
so ya adjust your Duty cycle and adjust your error correction. Sound like when you hitting above you load no adjustment is being made, then its overshooting big time because of you low end error correction.

 

That's assuming you have dialed into the boost you wanted... Can you imagine having zeroed out correction and run a car in 4 season (weather) like PA?... It would be like having a MBC in your car....