Recently I installed B5S4 calipers and slotted cross drilled rotors (from ECS Tuning) and everything worked great. Today, we got the very first snow storm. I took the car out for a short trip to supermarket... man... it was scary... Whenever I press the brake, the ABS came on even when at 5 MPH and hit brakes. It also nearly impossible to stop.

Anyone had or heard about this issue before? What could be wrong?

Thanks.

 

You've got to down shift and control your speed with the gas pedal! The goal for your brakes is to stop the wheels and tires from moving, a bigger brake set will increase your effective braking power. ABS should kick in faster since your brakes are doing their jobs.

If you have an auto use the sports setting or tip mode. If it is a manual, you know what to do!

 

stopping/slowing down in a snow, you gotta learn how to do it, best way is to downshift.
i would suggest for you to go find some parking lot with a lot of snow and practice over there.

 

It's not like I never drive in snow before. But, the car just feels so different when braking in snow after I changed the front calipers to B5S4. Like b4thea4 said, maybe because the calipers have better effective braking power. You're correct too, I need to practice more and get the feeling about those new calipers. The reason I asked here just want to make sure there is nothing wrong with my brakes because they were replaced by me and a friend of mine; not pros. :P

 

if it worked fine before the snow then you should be ok
your new brakes grab harder, so abs kicks in faster and harder too.

are you at least on all season tires?

 

Yup, I am running on all season tires. Well... I guess I'm just worry too much.

 

^ you are

 

Holy ****...I have the same issue. I just bought an 04 A6 s-line and almost totaled it yesterday. Just a bit of snow and as soon as I touch the brakes the ABS goes off and the car slides. Then you are trying to stop a 4,000 pound car with no hope for survival. I used to drive a stick (hyundai) and that thing felt better in the snow. I posted a similar thread just minutes ago and found yours. It seems we need to use the tiptronic more. But I am with you...it was freaking scary. Almost totaled it after 1 month. The brakes just don't help in the snow.
have fun.

 

You've got two friction surfaces you're dealing with here...the brake pad to rotor surface area and the contact patch between your tires and the road. You've dramatically increased the surface area of your braking components without increasing the coefficient of friction between your tires and the road. Basically this means exactly what others have posted...your bigger brakes are making it easier to get to the point of lockup/ABS intervention with less pedal effort on your part.

If you were to swap out for snow tires you'd likely notice a significant improvement as they're going to be alot grippier in slippery conditions, but basically this is the way its going to be and you've just got to get used to it.

I don't recommend you get overly dependant on using the transmission and throttle to do much of your braking...its imperative that your brainf and right foot make the adjustment to learn how the new brakes work, otherwise you're going to get in a wreck when you're in a panic stop situation and you don't have the time to downshift.