Finally after corresponding with Doug at FrankenTurbo and the support at Auber Instruments for a few days I was able to get the Auber Air Temperature sensor properly wired up to the LMA-3 so that I could log air temperatures coming out of the the turbocharger compressor.  The sensor probe is located in the metal hard pipe that joins the turbo compressor outlet and the intercooler inlet – so these readings are approximately what the compressor is putting out without the benefit of passing through the heat exchanger.

It was a bit late in the day when I finally got it hooked up and the S4 out onto the road for a test drive to see how the logging worked, so there’s only a very small boost event that is in 2nd gear.  Nevertheless the results below are interesting to me.

The chart above shows on the left hand vertical axis boost pressure, both at the compressor (CAP), and at the Intake Manifold (MAP).  The AFR is also logged on this axis.  Even at these low boost pressures there is some noticeable drop in boost pressure from the compressor to the intake manifold.

Along the second vertical axis is the temperature scale for the Outside air temperature (OAT), the intake air temperature (IAT) as measured by the vehicles intake air temperature sensor, as well as the new addition, the Auber recorded Compressor Outlet Temperature (COT).  Even the performance of the S4 Stock Intercoolers looks impressive when the flat line of the IAT is compared to the compressor outlet temperature.  On the other hand at four to five psi the turbo’s are pushing the air temps up approximately 30 degF, I’ll be curious to see what happens with these temperatures with higher boost levels.

Been working on setting up an Innovate LMA-3 Aux Box on the S4 to add in some additional sensors and to complement the Innovate LM-1 that I already have.  The Aux Box has a number of options for using internal and external sensors.  Today I was able to get the RPM input connected and configured as well as the 3 BAR MAP sensor.

The LMA-3 MAP sensor is tied into the wastegate signal line which is fed from the compressor housing, I’m very interested to compare the pressure at the turbo compressor housing with that at the intake manifold, where pressure is measured by the vehicle MAP sensor.

For kicks I loaded up a couple of tunes that run more boost than the stock profile, one targeted around 16 psi and the other just passing 20 psi.  Two of the more interesting results from this new configuration are displayed below.

The chart above is the most relevant to the new capabilities offered by the LMA-3, it shows how at lower rpm the pressure losses from the turbo compressor housing outlet to the intake manifold are minimal, but around 4000 rpm at 16 psi the pressure at the intake manifold is beginning to drop below the level at the turbocharger.

The car is presently equipped with stock intercoolers which during the Intercooler Faceoff flow testing were shown to lag most aftermarket options with regard to pressure drop across the core.

The next chart is one that I was interested in just for baseline comparison purposes, to be able to assess some of the larger turbocharger options against the smaller K03’s in the one area that a K03 should have an advantage, that is in spool up at lower rpms.  The F4H-BT tune was set to hold 21 psi so as that boost level is approached the boost rise rate slows.  If the boost level for the F4H was left higher the rate would have continued along the path it was taking prior to reaching 21 psi.