Powerlogger files, Surging Issue, Help!

[bholker]

Been troubleshooting an issue where the car will surge up and down at mid boost, (10 PSI or so). If I hold the throttle in this boost range it's very noticable, not as much when at WOT and just go across this zone, but my AFR is real erratic 'til I get into 2nd gear at WOT.
Just installed the TurboTweak 6.0 chip and got some input from Eric, but still don't have it nailed down.
Figured it was related to my boost control, but last thing I tried was to disconnect the boost control line completely from the wastegate and plugged the PSI line from the turbo. Light on throttle watching boost real close and it still does it. So must not be wastegate actuator related.
Run 1 file is from part throttle form a WOT run. Notice that as boost comes in AFR spikes way rich, then it's up and down 'til it finally settles out 'bout the time it shifts into 2nd.
Run 2 is a part throttle run holding at around 9-10 psi boost. This run you can see the boost up and down along with MAF, RPM, AFR, and probably some other stuff.
Both these runs were with the wastegate plumbed per normal, but same issue when I disconnected the wastegate. What thinking maybe the wastegate was opening and closing, but that must not be it.
Anyone see anything in here that may point to root cause, or have ideas on how to toubleshoot the issue.

 

[NCTURBOS]

What turbo?


K.

 

[bholker]

Stock Turbo.
Running straight E85 w/ TT E85 6.0 chip.

 

[TurboDave]

Run 1 looks pretty normal to me. And your A/F ratio didn't exactly spike WAY rich, it only went to 11.6

Run 2 there is some compressor surge but not huge.

I'd suggest trying to run normal gas for a while with a non E85 chip. See if it clears up.

Is 12.2 norma for E85 WOT A/F ratio. Too lean for gasoline, but I don't know what's good for E85

 

[4-71/Z-28]

That is very lean for gas, I thought e85 afr's were in the neighborhood of methanol 5.0-1, but a point or 2 leaner because of the 15% gas