I was thinking about it, on a perfectly DRY road and u want to stop in a straight line, wouldn't locking them up stop the car faster because of more contant friction over the braking distance??? I can see that abs will give u more CONTROL in braking and be MUCH better in the rain, but for the situation above is abs actually not benificial??? Thanks

 

i think the friction between the brake pad / rotor is greater than that of rubber / assphalt

rubber and asphalt both contain oils while brake pad / rotor does not

besides the pad / rotor is a much more control envrionment than the street and your tire.

 

& long skids eat away at your tires.

 

According to the people who sell the parts (oem suppliers), you will stop faster on dry pavement WITH ABS. On surfaces with reduced traction you will have more control over the vehicles dirction WITH ABS.

Technically if your tires skid the friction is reduced = less friction = less grip. Think of it in reverse - in a race you spin, I win.


My own experience when I used to work for a dealership I was out abusing an Olds Aurora. Somebody pulled out of a driveway in front of me and I LAID on the brakes. I couldnt believe how quickly that car came to a halt! Also I had a sn95 cobra a while ago. That thing had BAD A$$ brakes/ABS.

In most cases ABS = good

 

oh yea, ever try to steer a car with locked front wheels?

 

Static friction is much greater than kinetic friction. You don't wan't the tires to lock up and skid. You will get much less traction that way. You want to stay just below the point of skidding, which is what ABS does, whether it's dry, wet, or snowy surfaces.

I've tested the ABS at the GM proving grounds in Milford, MI. If you ever have two side tires on dry pavement and the other two on a slick surface and you nail the brake, you will instantly start doing donuts. I did this at about 45 mph. It was pretty fun. Turn on the ABS, and no spin whatsoever.

Dan

 

We had a good discussion of braking and traction while I was at a Skip Barber class. The cliff notes summary is that there is a "profile" of traction for a tire, based on the rubber compound, that shows that the best traction (accelerating or braking) happens when the tire slips by X%. X varying by tire compound, and being something like 5-10%. So when braking, you'd like just a little bit of slip, and same with accelerating. An R-compound tire has a taller/skinnier profile that allows higher traction, but a narrower window (ie, push it a bit beyond that slip and it immediately goes to skid), whereas a street tire has a lower/broader profile (ie, lower traction level, but more predictable lock-up).

That discussion leads you to one of how the ABS is implemented. An ABS system on most cars is either on or off, in that it is rapidly releasing brakes (no slip at all) or locking brakes (skid, assuming the driver is pushing the pedal as hard as possible). Neither of those conditions is optimal on the slip curve. So the question becomes one of whether your brain and foot can do better than the ABS flavor of "skid/no slip/skid/no slip/skid" by creating a "slip 5%" scenario.

Dave

 

IMO it would be next to impossible to manually do a 5% slip with your foot especially in an emergency "panic" stop (when it counts).

Also the ABS works according to what it sees @ the wheel speed sensor/reluctor ring which is not necessarily what is happening between the tire and the pavement. Factor in the flex of the tread blocks and the sidewall of the tire and the "skid/slip/skid/slip" at the WSS and reluctor ring might just end up being actual 5% slip between the tire and the road surface.

All I know is it werks gud

 

Good points, Dave.

Were you able to stop better with the ABS off? How many practice tries did it take to master the threshold braking? Are they still using Neons?

In the real world of OMYGOD! emergency braking, ABS will outperform even a Skip-school graduate most of the time, especailly if you have practiced max ABS braking from about 70 mph with lane change thrown in.

IMO, which is never humble, if you try a practice 70-80 mph max stop with a Camaro (or other modern car) on dry pavement you won't push hard enough to get full ABS cycling the first time you try. It's something I think folks should practice under controlled conditions.

My $.02

 

I didnt read it all but looked good on the short round

http://www.team-orion.ch/faq/car-handling2.asp

 

ABS is your best friend unless you want to go off road, but then again, I don't know any F-body owners that take their cars off-road. Maybe some do, you never know. 33" mud-tires and 10 inch lift on a Camaro, now that would be funny.

 

What he said. Also, as someone mentioned already, you can't turn if the front wheels are locked up.

 

I was in their formula Dodge car, which is a neon engined, ~900lb formula. Very fun to drive, but it doesn't have ABS. I can't say I came even close to mastering threshold braking, though we did spend about an hour going through turn 11 at Laguna Seca (for those of you that know the turn) over and over again working on threshold, then trail braking. I can say that when you do get it right (for me 1 out of about every 3-4 tries) you feel like a hero. The rest of the time you end up in the dirt.

Absolutely, apologies if my post implied otherwise. There's clearly a significant difference between the technical classroom description of what's going on, and the real life experience. My ABS fuse remains in the Camaro...

Dave

 

i see, thanks for all the replies. The static friction vs kinetic makes sense to me. I was just wondering because when i changed my rear out i had to disable my ABS and 3 nights ago 2 deer jumped out in front of me at night and i was going about 60. I was used to having ABS all the time so i just mashed the brake to the floor, the tires locked hard core, tires squelling, HUGE tire smoke cloud all over when i stopped, i couldn't see the road or the deer because of all the smoke, lol. It seemed to stop pretty good though, hence the question. Thanks.

 

I'll bet there was deer scat all over the road!

With your ABS on you stopping distance would probably have been shorter, and you wouldn't have the flat spots on your tires.

Hook it back up and practice some "deer stops".