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.