A few updates.
I ended up purchasing two piggyback units and will be exploring them over the next few months - JB4 and ESS. I'm enjoying the logging and customer support of the JB4. I haven't yet decided if I will put on the ESS but we'll see. The ESS probably provides more gains than the JB4 from what I've seen but Stage 1 on the JB4 provides unbelievable power as is.
Admsit all the worry about potentially throwing codes upon installation of a piggyback, just before I was about to install the JB4 my *stock/babied* 6MT F80 with 5k miles threw a drivetrain error code coasting down the street. Pulled over, car idled rough, cycled the ignition, and code goes away. Hasn't been back. Maybe it was gas.
So all the threads about these cars throwing codes seems to be true. In fact, when I cleared my codes after installing the JB4, I had 13. (I also got a drivetrain error when I coded the VO to activate enhanced bluetooth, but I ended up returning to that to stock.) I suppose showing up at dealer without any codes is more indicative playing around under the hood than having them. (140010, 140210, 140001, 140201, CD8420, 121530, 000000, 0000F1, 241044, 022812, 15F125, 302812, anyone?)
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I will attempt to illustrate how the car responds in terms if boost at an elevation of 6000 ft. Shown below are log runs using Map1 on a JB4 in comparison to Map 3 and Map 4. Map 1 provides a constant +4psi regardless of RPM. Map 3 is designed to be slightly more conservative at higher RPM for low octane fuel. Map 4 is a bypass map and simply allows you to log your information.
This first graph shows three logs. The recorded psi "ecu_psi x" after the car has compensated for being told that the boost is too low, the actual manifold pressure due to the piggyback "boost x", and the added boost "target boost". The target boost for Map 4 is zero since it is a stock map. You can see how Map 3 adjusts the target boost up then down and how the actual MAP pressure changes in response.
Also of note, the car stock produces around +18psi maximum boost at an elevation of 6000 ft with air temperature at 32F. This is similar to what I've seen others show at sea level. So the car does not appear to be adding more boost at elevation than at sea level unless the boost goes up considerably when the intake temperatures are hotter, which it should. Stated otherwise, it does not seem like the car is trying to achieve an absolute MAP pressure of (18+14.7) = 32.6psi, rather it is happy producing less power at (18 + 11.9) = 29.9. I'll get another run when it warms up.
(3rd gear, 6000ft, 32F, no mods other than JB4)
The second image shows the air to fuel ratio for all three maps. Nice alignment between the three.
(3rd gear, 6000ft, 32F, no mods other than JB4)
