braking behavior in snow.

[naimouasta]

so its snowing tonight here in SE PA where i live. not so much yet, maybe 1in, but its so slippery out because below the snow is ice patches everywhere. almost fell on my ass.

 

not running any snow tires. kumho asx 235/40/18. not the most ideal size or tire but i managed as long as i wasn't being stupid. there was a big hill with a stop lights in the middle of it. i was able to make it up the hill with no trouble, while many people went no where, except the outback following me. subaru power! LOL.

 

anyway on the back roads i was testing braking and accelerating and took some observations.

 

1. accelerating really hard up small inclines, the car wanted to pull right most of the time, with the steering wheel straight. alignment issue?!?

 

2. the abs comes on with moderate braking, but if i put the brake pedal through the floor, the abs turns off and just locks up?

 

3. whenever the wheels lock completely at slow speeds coming to a stop, the car suddenly slides laterally to the right; everytime. where does EBD come into play? isn't it supposed to keep the car straight? is this an alignment issue with pull to the right?

 

4. having no LSD sucks balls, as bad and slow as some of you say the vLSD is, i'd rather have one. without one, you can tell the power is escaping through either one of the wheels. its very unpredictable, sometimes power gets to the wheels and its goes, sometimes it doesn't and goes no where; so it doesn't respond like you would want to.

 

compare that to my old wrx, my brother 2.5rs, or dad's forester; all with lsd's, yes the rear kicks out easier, but they are more predictable and controllable with proper skills.

 

conclusion: fun time tonight. just curious how abs and ebd come into play. also curious why my car keeps pulling right.

[SubyShop.com]

My guess would be the slight pitch of the road is causing the car to slide to the ride when slippage occurs. Seems odd about the abs coming on with moderate braking and turning off with the pedal to the floor. Maybe you are just seeing variations in traction on the road surface?

-Franz

[naimouasta]

My guess would be the slight pitch of the road is causing the car to slide to the ride when slippage occurs. Seems odd about the abs coming on with moderate braking and turning off with the pedal to the floor. Maybe you are just seeing variations in traction on the road surface?

-Franz

 

hmm. maybe i'll try in a flat parking lot and see if my car still slides to the right. and it does seem odd that abs stops with very hard braking. i had my brother stand outside and watch and he says the wheels do just lock up and stay locked. maybe thats just how the system works in very low traction situations vs. on the dry street. should be nothing wrong with my car, no flashing abs/brake lights of any kind.

[ebpda9]

Well abs only works when it sees a difference in speed between the wheels. Once all 4 wheels locked up the abs controller thinks that the car is stopped so it won't cycle anymore, that's why the wheels stay locked up.

 

As far as the pulling to the right mine does it too, regardless of the inclination of the surface i am on. I noticed that all the 2.5i's 05+ have a slight lean to the left, less caster on the passenger side. That leads me to believe that the geometry of the car has more to do with the pull than the braking system or tires.

[naimouasta]

ic, that makes sense about the abs.

 

also aren't all subaru's uneven in height anyways which explains uneven geometry left to right.

 

12+ inches tomorow! i don't know if i should be scared or happy. be safe everyone

[mwiener2]

1. probably has more to do with the actual road, the weight distribution of the car, your tires, the surface conditions than alignment

 

2. under moderate braking it's working fine. When you press hard all four lock up and as mentioned before, the car thinks it's stopped. If you had a manual transmission, you'd stall the engine. (if you don't clutch)

 

3. EBD simply moves brake force to the rear of the car when needed. Such as when you have a lot of stuff in the trunk, or 3 people in the back seat. It's meant to shorten stopping distances in panic situations from higher speeds. Like coming up on stopped traffic on the highway.

 

4. yeah, sucks

 

you may have an alignment issue, get it checked if it concerns you. Most places only charge $25 for a check