4 wheel skid under braking
 

So yesterday I was going up on kennedy north of 407 on my way home, right about where the bmw dealership is. As I was approaching a red light with cars stopped, I went onto the brake. It was only about 40 or 50% braking from about 75 km/h or so. As soon as I brake all 4 wheels skidded and the abs pulsed slightly. I lifted off and braked again and the abs pulsed a bit. The car wasn't slowing down at a sufficient rate and i went hard on the pedal and i moved slightly to the left of the lane just to give myself a few extra centimeters to stop the car before i rear end the guy ahead of me. It was unbelievable how little grip there was. Yes it was dry and brakes were up to operating temperature. And to add insult to injury, an ugly soccer mom in the left turn lane couldn't resist a cheap shot at me, telling me maybe I should put the training wheels on or something like that. What was she driving? One of those ugly bloated SUVs that you always find upside down in a ditch. :shakes head:

After lunch I decided to head back to that location to try and find out why this has happened. Traffic was accumulating in the northbound lanes so I tried the southbound lanes and I was able to replicate the problem twice. Basically a moderately hard braking, about 50% or so causes all the wheels to skid and weakens braking ability. I doubt it was ice mode since I didn't hit any bumps nor did the brake pedal become excessively stiff. There is a lot of construction in the area, so could it be dust from there blowing onto the road? We had lots of rain the week before so I would have thought it would all be washed away. What I am certain of is that this problem is only specific to this stretch of road since I couldn't replicate it anywhere else.

Probably just a slick spot for one reason or another. Someone could have dropped some oil or it could have been dirt on the road. It can be hard to tell sometimes. I've had it happen to me slowing for certain intersections in a variety of cars.

The important thing to take out of it is that we can never assume we will have full grip on the street, so you always need to leave a little bit of a buffer in case you encounter a situation like the one you described.

for a second this story reminded me of my old 02 WRX (was new at the time) that had over reacting biotch ABS where any quick dips or bumps on the road would extend braking distance by about a mile. :icon14:

i pulled the ABS fuse after that incident. i dont think there's anything wrong with the Z's abs.. must be that stretch of road.

also when it pulses people tend to let off the brake pedal. dont. just keep pressing while the system calculates your previous brownie points and begins decleration. ;)

:bowrofl::icon18:

Try washing the tire itself. You be surprised how much fine dust these tires picked up compared to "truck" tires. When I was doing canyon runs, this is one of the reasons why I check out tread design. Flat surface tires are one of the reasons why a bunch of cars meet their maker early thanks to fine dust.

Your other thread could have a lot to do with it...

http://www.the370z.com/suspension-br...-problems.html

oh yah... i remember reading that one. just keep the brakes stock unless you know exactly wat you're doing, i guess.

ice mode

are you sure all four locked up? thats kinda rare. sure it wasnt just the fronts?

I'd be looking for an oil slick somewhere.

Any road construction in the area? I know I've had a similar situation, although not 4 wheel lock when stopping hard on grooved pavement, almost feels like you're hydroplaning?

notsureifsrs/10


So like, you shouldn't tail the crap out of the car in front of you on the dragon?:roflpuke2:

:icon18:

im guessing u play dota?