ryoung

The footnote in that chart in their Brake Bias whitepaper says "Without EBD or ABS active". Probably most who upgrade their calipers track their car; and probably most who track their car, prefer to stay out of ABS (even if they don't pull the fuse). Without ABS, the wrong brake bias will result in increased stopping distances and possible instability. Even with ABS, a badly screwed up brake bias will increase stopping distances slightly.

I'm not sure if any Audi's have Electronic Brake Force Distribution (EBD), but the D2 A8/S8 does not.

<img src="http://www.stoptech.com/whitepapers/stoptech_balanced_chartweb.jpg">

StopTech Sales

We do all our tests on the same car the same day with the same tires. The Chart in question has a footnote regarding rear bias only that says if ABS is disabled then the platform is unstable.

The Stopping tests were done with ABS enabled.
We do have a suite of tests that includes an ABS disabled test to insure we have front bias. We also check heading angle in our J-turn tests to compare F/R bias versus stock.

The distances get worse on any platform as you increase front brake torque past the stock torque (keeping tires and surface mu the same).

Some platforms e.g. 3/4 ton trucks punish you severely if you fall off the stored PV curve.

We are the only after market brake company that bothers to do this extensive testing. We could just as easily make 40-44 calipers as 36-40. The S4 stops better with 36-40 front pistons sizes versus the 40-44. If you put on more aggressive friction and keep the tires constant you will increase stopping distance. We measured a 5 foot increase in a M5 going from stock to Pagid blue at 80-0. Is anyone else trying to explain these issues?

If you do your homework you find we have our science correct. We do not bend the laws of physics to suit our purposes.

Bob Lee
StopTech LLC

qfrog Ti20

I'm just turned off by itty bitty little asteriks with important info attached as if it were meant to be overlooked. That is the sort of thing I expect from somebody that has some thing important to hide. I've never said anything bad about your products, however I dont trust technical information in article form published by mfgs, thats just how I am.

ryoung

that the note "without EBD or ABS active" applied to the entire chart, not just the "Platform Unstable" section.

BTW: I had said "Even with ABS, a badly screwed up brake bias will increase stopping distances slightly." You measured a 5 foot increase in a M5 going from stock to Pagid blue (I assume front only) at 80-0. Going from a stock probably 0.35 cf pad to the 0.48 cf of the Pagid Blue is a huge shift in brake bias. Only a 5 ft increase in stopping distance is a credit to ABS, and I can imagine it'd be a huge increase without ABS.

StopTech Sales

There are never enough footnotes to satisfy the the technical reviewers. Until we raised the bias and balance issues, some people assumed certain manufacturers sprinkled Brake Pixie dust on their kits to make everything work. As the IBM ad states there is no brake pixie dust.
Hopefully we can engage you in the future with more technical data. I have three new non partisan articles planned for our technical section.