Today the Silver S4 went back to the Dyno for a series of pulls with some hardware configuration changes. Data from that is still under evaluation.
10/21/2016 Dyno Session
Because I was changing some hardware configurations I removed the front bumper and headlights for the morning. This allowed me a clear view of the intercoolers, or more correctly the thermal camera a clear view of the intercooler.
I snapped these images during one pull, the left image is from the early part of the pull and the right image is from the last part of the pull as the dyno operator lets off the accelerator.
SRM SMIC Thermal Image During Dyno Pull
As makes sense, the lower part of intercooler, where the charge air enters the core, is rising in temperature more rapidly than the upper part of the core, where the cooled air exits.
After setting the ABS bias to the RS4 code I went out to log stopping distance a few times in order to compare with the previously recorded S4 bias distances. With the larger StopTech 332 brake setup on the front of the car the idea with making the ABS bias to that of the RS4 is on account of the RS4 using larger brakes than the stock S4.
After swapping out stock S4 brake components for the larger StopTech setup, you “should” update the ABS bias to match the new setup more closely, how true is that idea?
Here’s the results:
RS4 ABS Bias vs S4 Bias
From these results it does not look like adjusting the ABS bias makes all that much difference to the stopping distance.
During three of the five S4 setting pulls the results were the same as what was achieved with the RS4 setting, or at least close enough that I consider the differences to be within a procedural margin of error.
It does not look like there is a significant benefit to changing the ABS bias from S4 to RS4 when upgrading the front brake setup. On the other hand, there’s no sign that doing so has any adverse affect.
Continuing on from the prior data logging session I recorded three more trials of hard breaking to get some additional data for the baseline case. The baseline setup uses the S4 brake bias setting along with the StopTech 332 Big Brake Kit on the front of my S4 and the stock setup on the rear, with the exception of StopTech’s stainless steel brake line at the rear as well as front of the car.
