Category Archives: Brake

Brake Swap In Progress

Given the better resistance to brake fade that the Stoptech brakes exhibited as compared to the stock S4 brakes during my braking test I’ve decided to install my Stoptech brakes on the Avant.

I began with removing the Stoptech’s from the driver’s side of my Silver Sedan and then removing the corresponding stock S4 brake from the Black Avant.  I was equipped this time with appropriate plugs for the ends of the brake hard lines, so that I did not have a brake fluid mess to deal with.

The install of the parts on the new vehicles went without fanfare.

Stoptech 332 BBK Installed on Audi B5 S4 Avant
Stoptech 332 BBK Installed on Audi B5 S4 Avant

With the driver’s side complete, aside from bleeding the brakes, I’ve stopped for the day and will try to get the passenger side completed tomorrow.

Also noticeable in the background is the blue shielding that covers the line to the Stasis/Ohlin Motorsport Oil Reservoir, the Motorsports are now completely in place on the Avant.

Brake Check ‘After’ Results

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:

Audi RS4 ABS Bias vs Audi S4 Brake Bias
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.

More Brake Checking

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.

S4 ABS Brake Bias Setting Data
S4 ABS Brake Bias Setting Data

Next up is the RS4 bias check.