ABS, advantage or disadvantage?

[Guest Hubbo]

If an ABS system could be fitted to a Zed, by whatever means (retrofit, aftermarket, what-ever..), would it be a disadvantage or disadvantage?

 

Logically, something that stops skidding and improves handling underbraking would be excellent. So why do people remove ABS on cars that alreadry have them (like in racing)? Are they really that heavy?

 

I recently came across a pic of an ABS part removed from a skyline. Links:

 

http://www.exvitermini.com/pics/abs.jpg (via the following page:)

http://www.exvitermini.com/pr33b.htm

 

Obviously this isn't the whole system. I guessed it might be the control valves, etc and maybe the pump.

To me it looks rather light.

[johnc]

So why do people remove ABS on cars that alreadry have them (like in racing)? Are they really that heavy?

 

Lots fo reasons:

 

1. Rules - many sanctioning bodies don't allow ABS for various classes.

2. Performance - many race drivers can outbrake ABS systems and this is especially true for older ABS systems. And some of the more recent ABS systems are so finely tuned that race rubber messes up their software and braking becomes unpredictable. Chevy's going into "Ice Mode" is a common problem.

3. Complexity - simplifying anything on a race car is a good thing because it makes maintenance easier and reduces the chance of something going wrong.

4. Weight - as you said and always remember most racers would kill to take 25 lbs out of their race cars.

5. Cost - how much does that ABS valving cost?

[Savage42]

As mentioned, a person can out brake ABS if they are good at threshold braking. I ran a BMW 540i 6-speed at Laguna Seca, which worked pretty well until the brakes got hot and the ABS started acting up. It was a bit unnerving and BMW has one of the better systems out there. I prefer cars without it. It's more of an aid for people who tend to "panic stop" by just stomping on the brakes to avoid or incur an accident. As for weight.....it doesn't make the car faster, so I wouldn't want it.

[Guest Hubbo]

Thanks guys. Some interesting points.

 

If its unreliable how about installing a on/off switch like they do on some driver training cars? ... food for thought.

 

When you guys talk about out-braking some one with ABS, is that just in a straight line, or corners too?

With ABS, doesn't it control individual brakes? To my thinking, an ABS car could reduce braking on an individual wheel to prevent skidding/lockup, where as an 'experienced' driver when threshold braking would reduce braking to ALL wheels just to stop one wheel locking-up.

[johnc]

> If its unreliable how about installing a on/off switch

> like they do on some driver training cars?

 

Now you've added a level of complexity to a supposedly already unreliable system. Also, the brake bias of an ABS equipped car is very different from an identical car not equipped with ABS. Turning off the ABS might make the car almost impossible to stop on a race track (the Acura NSX is one example).

 

> When you guys talk about out-braking some one with ABS,

> is that just in a straight line, or corners too?

 

ABS sometimes screws you up if you're trial braking a car into a corner. Again, with Chevy Camaros and Z06 Corvettes, when the software detects hard braking loads and a high yaw rate at the same time it occaisionally figures the car is on ice and dramatically reduces brake pressure to all 4 wheels. I've seen SS Camaros at autocrosses just fly off course with no brakes until the driver shuts the car off.

 

> With ABS, doesn't it control individual brakes? To my thinking,

> an ABS car could reduce braking on an individual wheel to

> prevent skidding/lockup, where as an 'experienced' driver

> when threshold braking would reduce braking to ALL wheels

> just to stop one wheel locking-up.

 

On a race track you're dealing with pretty much equal surface traction at all 4 wheels unlike street driving. Bumps can upset things and you can throw out the old "oil on the track" argument, but a properly balanced braking system will tend to lock up both wheels on either end instead of just one.

 

What's most important in braking while racing is consistency and predictability, not ultimate stopping distance. Whether Joe Racer can post shorter braking distances with his Super Tho Down Mo Fo ABS system is irrelevant if he can't do it every single time. All it takes is one corner where Joe Racer's ABS system kicks in a little early and, at best, he's off line and at worst, he's off track.

 

Now, that being said, for the average racer out there, ABS on a race track is a great help. If you are allowed to run it, do it. Also, many professional race series (SCCA WC GT and Touring) allow ABS and most drivers use it if testing proves it can work.

[Tim240z]

IMHO anything that assists the driver in controlling the vehicle (ABS, traction Control, Active suspension, active Aero, etc) in a racing situation is bogus.

 

I absoutely love watching old F1 coverage in heavy rain when Ayrton Senna, who was about 8 positions back before the rain, would absolutely dominate as soon as the track got slick. It took HP and chassis setup out of the equation and took it back down to the basics of racing......car control. Senna was a wizard....my favorite driver of all time (with Nikki Lauda, Fangio, Moss and Piquet right up there)

 

Tim

[gramercyjam]

With ABS, doesn't it control individual brakes? To my thinking, an ABS car could reduce braking on an individual wheel to prevent skidding/lockup,

 

You would think so, but I don't think that is the way ABS works on most grocery getters. I think at best, the front and rears may work independently on high end systems. Internet searches would get you the answers.

[Pop N Wood]

Good info from JohnC. I'll use this post in future arguments.

 

I can tell you from my ABS testing on rental cars that some of the cheaper ABS units simply alternate which wheel they want to lock up. I use to get cavaliers up to about 50-60 mph then stand on the brakes. The car would lurch and studder, and in the rear view I would see an alternating stitch work of skid marks where it alternated locking up the right and left tires. Heavier cars tended to work a little more smoothly, but the brakes still noticably pulsated left to right (causing steering instabilities) under full braking. I have never driven a BMW or NSX so I can't comment on those units.

 

Also you do know on gravel or snow covered roads, a car that can lock up the wheels will stop shorter than a car with ABS. Something about plowing a small pile of gravel/snow in front of the tires.

 

I personally don't see the need for ABS on a street car. Just another expensive thing to break. The way most people drive I would think you could add more safety with automatic tire inflators.

[Savage42]

IMHO anything that assists the driver in controlling the vehicle (ABS' date=' traction Control, Active suspension, active Aero, etc) in a racing situation is bogus.

 

I absoutely love watching old F1 coverage in heavy rain when Ayrton Senna, who was about 8 positions back before the rain, would absolutely dominate as soon as the track got slick. It took HP and chassis setup out of the equation and took it back down to the basics of racing......car control. Senna was a wizard....my favorite driver of all time (with Nikki Lauda, Fangio, Moss and Piquet right up there)

 

Tim[/quote']

 

Tim, I have to say AMEN to that. I was glad when Champ Car (aka CART) got rid of traction control. They are talking about changing a ton of rules in F1 to make it more of a driver's sport instead of an engineers sport. We'll see what happens, but I think F1 should just go back to big tires, underbody ventures (so they still have downforce when they get close to each other), no traction control, ABS, or any of that other crap. Nothing wrong with a driver having to learn more finess with the gas & brake pedal, don't you think?

[JMortensen]

I agree with you guys. Watching a driver perform is much more interesting than watching a car perform.

 

I suppose the other argument is that the technology developed there does trickle down to road cars, so if they stop developing this stuff than the potential downside is that we won't see it in the new $1,000,000 Enzo or the new $600K Mercedes...

[Guest Hubbo]

I agree, reducing driving aids brings it back to driver skill and can make a race much more interesting and fun, as with the example of Senna in the rain.

BUT... considering this, to bring it back to a driver's skill the driving aids (ABS, traction control, blah, blah....) must have been doing something, right?

Obviously ABS systems designed for 'grocery getters' weren't meant to be race driven. So hypothetically (theres that would again, ), if we designed an ABS system for the race track and by a miracle of god it was reliable won't we all use it?

[datsunlover]

Figure Id pipe up here.. I HATE ABS brakes. IMO, it takes away something from the driver, and gives it over to a computer.. which I dont like..just rubs me the wrong way. Also, my brother has had a problem recantly with his GM Astro van (95 I beleive..) Middle of a summer day, rolling to a stop sign.. and the ABS kicks in. (WTF?!?!??) Yah. He's literaly rolling through red lights and stop signs and theres nothing he can do about it! Scarry... Personally, I like the ability to lock the wheels up at any time I want/need too and I feel as though I have more control. (even though I am threshold braking or skiding a bit) There have been plenty of crashes caused by ppl relying on their ABS and the 'false sence of security' that it gives them. My girlfriend is a prime example. she hasn't cracked it up yet, but her 2002 Grand Am has ABS and WOW does she rely on it! Brakes way too late, drives too close behind ppl, and is always hamering on the binders as opposed to a slow aplication. (wonder why I had to replace the pads/rotors last fall.. yah, on a 2 year old car.) The idea is good, but IMO the tech/conputer end of it is not quite good enough yet. (as far as the general 'for the masses' vehicles) Yes, the newer systems are good, but I think it's more of a sales pitch for most cars "Its got ABS, it's safer." and it's worked. People like us understand this kind of thing, but a lot of the general public just thinks 'well, it's better becaue the car co. says it is'. Anyway, I would have to say it would be a dissadvantage IMO on a Z.

[Guest das280zx]

Purists don't like abs, and I didn't either, but I must say that they can be of great help on the track. In autocross, abs is known to provide a clear advantage. As a human, there is only so much you can do to modulate the brakes at near lockup. A good abs system can really be a benefit. But not in all situations. Like braking on ice is kind of sketchy with abs. ABS is definately not a necessity if you know how to drive good, but it can provide a good advantage, even for a skilled driver. Why do you think car mags always get better 70-0 braking distances with abs equipped cars? It is not because the testers are crappy drivers.