Ferocity02

iTrader: (59)

Added a log to the first post if anyone cares to take a look.

nonnieselman

iTrader: (10)

I would start by fixing all the exhaust leaks.

BLK02WS6

iTrader: (2)

Are you guys using a caculated pid to determine your fuel economy mpg, or actually filling the tank and figuring the mpg based on mileage? if you are using a pid (as GMCtrk eluded to), you may be having issues because of how the pid calculates mpg... I would have to look at the pid to find out, but that is a possibility...

Ferocity02

iTrader: (59)

I am using a calc.pid, and it's pretty close to actual. The mpg numbers I quoted are from the calc.pid averaged over my cruise, for both before and after the turbo. It uses the speed, injector flow rate, average injector pulse width, and engine speed to calculate fuel economy.

MPG(mi/gal) = {SAE.VSS.mph}/({GM.INJFLOW.lbpm}*(({GM.IBPW1}+{GM.IBPW1})/2)*{SAE.RPM}*4/6073)

For fun, I lowered my O2 switchpoints from 450mV to first 400mV, then to 370mV. There was no appreciable change in the wideband AFR, but the average O2 voltage dropped from ~460mV to ~405 mV, then to ~395mV. In stoich cruise my O2's range from about 40 to 740mV with the switchpoints at 370mV. No codes. I know this wouldn't fix the issue, it was more for experimenting.

GMCtrk

iTrader: (27)

Which injectors are you using?

smokeshow

iTrader: (16)

What kpa do you idle and cruise at?

Ferocity02

iTrader: (59)

Bosch LS2 72# @ 3bar injectors from FIC (I think). The invoice and flow data says 60# @ 3 bar, but they seem to think they sent me the wrong injectors.


Idle ~42 kPa
Cruise ~ 63 kPa

Vacuum was about the same before the turbo.

KHester84

Are you sure your timing is staying where it should when cruising? Do you have hills, etc on the road while logging? Just want to make sure this is this steady state, no boost mpg logging. I'd do a manual mpg calculation just to make sure the calculated PID is not off with the new injectors.

Ferocity02

iTrader: (59)

Timing is what it should be. The MPG calc pid closely matches actual MPG. The calc pid accounts for the size of the injectors so nothing should change when you change injector size.

TX Tahoe Z71

iTrader: (28)

In for results. Hope you get it figured out.