April 2015 vfacts - Commodore 6th, Falcon nowhere

[prydey]

Originally Posted by castellan

what happens is under wheel rotation it detects lock up and releases, but the wheel has to do a full rotation at less strength braking power until it detects again.

i don't think the wheel needs to do a full rotation.... you can feel the modulation, thats not a full rotation.

Originally Posted by castellan

The brake thumps donk donk donk donk before it stops and each donk is a brake release, I can out brake it by 1/4 the distance or half

ok. i'd be curious to know how you tested this theory.

[Spammy]

Originally Posted by castellan

I seen him loose his VS SS ute once coming around a sharp bend on the race track, I am sure what happened was the lean of the car was very much and it pulled on the proportioning valve mid right hand corner locking the rear a touch, he came back spinning out saying did you see that, I sad yep ! the VS SS ute does not have a rear sway bar and they lean over very much more so.

Hell I know what ABS is capable of and what it is not, than to have some twerps of the street try to inform me of something that they think I don't know of.


To know a cars capability's is a good thing as that way you know what it can and can't do.

on.

Can you explain how pulling on the brake proportioning valve locked the rear brakes. As I understand it, pulling on the valve releases the brake pressure to the rear to stop the back end locking up.

And you are completely wrong on abs full rotation story.

[Sprintey]

Originally Posted by Kieron

Yes it does, google it, rear steer due to the rods introducing lateral movement in the rear axle and it's the reason why a watts link is superior. I had a VC Commodore company car in the 80's, then a VK followed by a VL, all would oversteer when pushed, the VL was the worst. Even drove a retired Commodore Cup car about 10 years ago and the trick was to anticipate the oversteer and 'drive thru it'.

Originally Posted by castellan

As for the panhard rod and oversteer, it's mainly got to do with balance and the front set up geometry.
The VB would be totally controllable oversteer, it was magic.
The VL Turbo I drove was just rubbish dog handling as they came out.

It's been a very interesting thread actually, all this discussion of ABS, driver skill; with the P76 and suspension tuning thrown in. No racing here, just a mug punter with a couple of million country kms under the belt, so ABS for me.

I can add to the quotes above, driving brother's mint VH 253 auto and overtaking a long semi trailer at 130+ in a 2 lane setup coming down a hill on a sweeping left bend, a bump or corrugation unsettled the rear and suddenly the car was in oversteer. Quite a shock when all I had experienced of the car was smooth and docile before this. My HZ (or ED or anything else) would not have done that.

[castellan]

Originally Posted by prydey

i don't think the wheel needs to do a full rotation.... you can feel the modulation, thats not a full rotation.



ok. i'd be curious to know how you tested this theory.

It feels like a full wheel rotation it may not be a full but it sure feels like it when you are nearly going to run up the rear of another car.

It's not a theory, it a fact as each donk you hear is the less brake power.

Just toddle along at 30 km/h and slam on the brakes, not all ABS is the same as some are more advanced than others.

As I just mentioned it once to my mate and he said he had the same experience him self.

[Kieron]

Originally Posted by Spammy

Can you explain how pulling on the brake proportioning valve locked the rear brakes. As I understand it, pulling on the valve releases the brake pressure to the rear to stop the back end locking up.

Thats what I would have thought too. Potentially I guess, heavily loading one wheel in a when cornering could trigger the proportioning valve to open

And you are completely wrong on abs full rotation story.

Definitely wrong. ABS has a 'tone ring' with many teeth that will trigger brake release on lockup.

[XR Martin]

Dont forget Electonic Brake Force Distribution. Basically when the ABS computer thinks you're doing an emergency brake it applies 100% pressure to all brakes.
Something a car without ABS cannot achieve.

[castellan]

Originally Posted by Sprintey

It's been a very interesting thread actually, all this discussion of ABS, driver skill; with the P76 and suspension tuning thrown in. No racing here, just a mug punter with a couple of million country kms under the belt, so ABS for me.

I can add to the quotes above, driving brother's mint VH 253 auto and overtaking a long semi trailer at 130+ in a 2 lane setup coming down a hill on a sweeping left bend, a bump or corrugation unsettled the rear and suddenly the car was in oversteer. Quite a shock when all I had experienced of the car was smooth and docile before this. My HZ (or ED or anything else) would not have done that.

Hi Sprintey
Bad shocks will do that in any car and HZ Holden's had a panhard rod.
Bad tyres wrong pressure will only add to that.

I drove a dudes ED falcon for him once and the shocks were just hopeless, it was totally a danger to drive and I know of another dude with a VR commodore that's the same, it just wallows all over the place, they think they have a nice car that rides well, but the fact is people who drive cars like this around are just morons and if they ever run into and kill someone with a car like that, I would call that premeditated murder.(no one has a hope of truly controlling a car like that)
I don't know how many people I have come across that are just so totally ignorant of the facts.
I say to them, listen mate, when it comes to the point at hand, in say the lead up to that when one has to take action, to avoid a situation, it's at this point that one must understand that the common sense importance of knowing and understanding what can or is happening or will happen when trying to be avoiding the crash, they have failed to comprehend this point totally, as it's out of mind out of sight. you just can't tell them.

It's like if you walked down the street and some punk tried to punch you, then you would be taken by surprise. but if you were wise and prudent walking down the road and some punk try's it on you, well you are prepared to deal with that situation directly at hand.
It's all about for knowledge in dealing with mastering things, instead of people just being a dill and just getting about in total ignorance, like most people do.

In court they say 'I just lost control of the car'! that's no excuse !

[Express]

Originally Posted by XR6 Martin

Dont forget Electonic Brake Force Distribution. Basically when the ABS computer thinks you're doing an emergency brake it applies 100% pressure to all brakes.
Something a car without ABS cannot achieve.

As XR6 Martin has already mentioned, to compliment ABS there is also EBV (electronic brake force distribution) to monitor and control the brake pressure on the rear wheels to improve driving stability when braking.

There is also Brake Assist.

My Merc calls it BAS (brake assist), my BMW calls it DBC (dynamic brake control) and my VE Ute calls it EBA (electronic brake assist).

I quote from my Merc owner’s manual.

BAS operates in emergency braking situations. If you depress the brake pedal quickly, BAS automatically boosts the braking force, thus shortening the stopping distance.

Keep the brake pedal firmly depressed until the emergency braking situation is over. ABS prevents the wheels from locking.

The brakes will function as usual once you release the brake pedal. BAS is deactivated.

Mercedes says these systems offer several advantages: a system that doesn’t lock the brakes, a system that improves stability, a system that applies far more pressure than a human can therefore decreasing braking distance and these systems take into account the natural instinct of most drivers who hit the brakes hard in an emergency and continue to apply as much pressure as they can on the pedal until the vehicle stops.

People who can’t see the benefit of these systems for the everyday commuter are nuts.

[castellan]

Originally Posted by Express

As XR6 Martin has already mentioned, to compliment ABS there is also EBV (electronic brake force distribution) to monitor and control the brake pressure on the rear wheels to improve driving stability when braking.

There is also Brake Assist.

My Merc calls it BAS (brake assist), my BMW calls it DBC (dynamic brake control) and my VE Ute calls it EBA (electronic brake assist).

I quote from my Merc owner’s manual.



Mercedes says these systems offer several advantages: a system that doesn’t lock the brakes, a system that improves stability, a system that applies far more pressure than a human can therefore decreasing braking distance and these systems take into account the natural instinct of most drivers who hit the brakes hard in an emergency and continue to apply as much pressure as they can on the pedal until the vehicle stops.

People who can’t see the benefit of these systems for the everyday commuter are nuts.

Most people are just ignorant I would say, as they think it's some magical fairy at work rather than a system.

One could Say this ABS system is better than another ABS system and one can start up a conversation on that line, as to asking why it is so.

Any ABS system is better for the average commuter and I have never heard anyone say that's it's not so ever. it should be mandatory for idiots.

When people look to buy a car, they look at all the safety features and think these things are going to save them, the biggest safety feature is the one who is driving.

The biggest problem we have is governments lacking the guts to make people do practical hands on driver training instruction, to prove they are capable of controlling a car and all.

Peter Brock invited me to the Norwell performance driving centre and their were a lot of people who came to the place in nice performance cars and then when putting their skills to the test, I was shocked to see how many were just so hopeless, they had no idea how to control a car much at all.
I just thought that people who drove performance cars would be of a better class than your average bear, before that day.

[Express]

I don’t claim to be a great driver, maybe I’m marginally better than my wife. I started to learn car control in the clover fields back home when I was about 7 or 8. There was no such thing as driver assists back then in the mid 1960's apart from a steering wheel.

One thing I have noticed over the years is the number of people who when met with an emergency instinctively go for the brakes in a big way. Anyone who’s done a driver awareness course of some type would know there are many instances when that is possibly the biggest mistake they can make. Once you’re on the brakes physics takes over and that doesn’t necessarily mean a good thing for the vehicle occupants.

Driver’s assists are great for the most of us because we are never taught to drive a car (car control) we are taught to get a driver’s licence.

That will always be my argument, cars are being designed for the masses or if I was to be cruel, the lowest common denominator in much the same way as our laws are legislated.

[Davehoos]

DRIVER EDUCATION.

I attended a 2 car crash as a fire call out last weekend. turbo falcon ute over taking slow traffic-P plater that slowed to allow to pass. It had gone wide over fog line putting rear tire on loose stone. After the stone was 1 tyre skid mark that helped it to over steer into the overtaken car. then there is 3 skid marks that I guess that when the forester pushed the falcon off the road. the Ute spinning off the road anti clockwise into a long grass wet field through the fence around 100 meters.

VH commodore had panhard rear. they also had many and varied suspension setups before the owners modified them. MY VH would often jump around due to mismatch shock/spring rates. some had fixed or varied rate springs.

The cars of the 70's had been much more forgiving. I owner a P76 that used a holden like 4 link system [Cortina copy]. It would lift a leg as the spring was bolted to the arm with very little travel but the front wheels had miles of travel.

[asagaai]

Originally Posted by Express

One thing I have noticed over the years is the number of people who when met with an emergency instinctively go for the brakes in a big way. Anyone who’s done a driver awareness course of some type would know there are many instances when that is possibly the biggest mistake they can make. Once you’re on the brakes physics takes over and that doesn’t necessarily mean a good thing for the vehicle occupants.

Driver’s assists are great for the most of us because we are never taught to drive a car (car control) we are taught to get a driver’s licence.

.

See I agree with the thrust of what you are saying- drivers today are not taught how it feels to lock up brakes at 100 kph in the wet, or what a slide round a corner feels like.

Just taught my daughter to drive- tried to do some lockup stuff and heavy braking and I was vetoed by all the progesterone in the house. She got her licence first up-I did not think she was ready....

I learnt with my brother- pair of us hoons- remember dragging an unmarked v8 cop car at lights in his worked Cortina te- full on drag race that the cop was into as well, next lights he finally pulls up to me and flashes his badge yelling abuse- ****ed being dragged by a car with L plates- did not book me cause he was in on the raced as well.

We took our cars on pads, tracks etc pushing, I wiped out a lot but learnt about how to handle a car. Unlike my daughter.

But, in terms of a real emergency, a person running out in front of you etc, a good driver will react and brake fast, but invariably hit too hard and lock up. A good driver will be quick to react and release and steer- but that's where abs is so good.

I remember driving back from a surf in my Cortina TE at probably 65 in a 60, and a kid on a bike svered across the road in front, I hit the brakes, locked up, released, re applied and steered to the left- he was cutting right. Closest shave I have ever had hitting a person-and I was not good enough to avoid locking up-abs would have helped me.

I think everyone should learn how to drive in a car without traction control abs and do all that sliding stuff, but still think abs is invaluable - for all drivers on the road.

[prydey]

Originally Posted by asagaai

I think everyone should learn how to drive in a car without traction control abs and do all that sliding stuff,

i don't agree.

how many accidents or deaths are as a result of lack of car control, and of those, how many were already breaking a range of other rules before they got to that point?

the biggest killer on the roads is probably drugs and alcohol, and inattention.

enthusiasts are an absolute minority. most people just use their vehicles as transport from A - B. they don't get anywhere near the limits of what the vehicle is capable of.

[asagaai]

Originally Posted by prydey

i don't agree.

how many accidents or deaths are as a result of lack of car control, and of those, how many were already breaking a range of other rules before they got to that point?

the biggest killer on the roads is probably drugs and alcohol, and inattention.

enthusiasts are an absolute minority. most people just use their vehicles as transport from A - B. they don't get anywhere near the limits of what the vehicle is capable of.

See I don't agree.

I remember riding my pushbike in the wet into Monash Uni as a student, while going round a roundabout I heard a screeching sound and turned around and there I saw this girl- who was in a slide- locked up brakes, and SHE HAD released the steering wheel and was covering her eyes and screaming.....obviously the first time she had experienced a slide in the wet and she panicked and FAILED in car control.

I was involved in a case where a lady was cruising at 100 kph along a freeway and on a curve she hit water that was running off from a public utility access road, she got into an aquaplaning slide, locked up and went sideways into an oncoming holden going at 100 kph.

Killed herself and her daughter.

I managed thousands of personal injury cases -CTP, for insurers, ironic given I am a now frustrated revhead.

Over the course of some 14 years, most deaths were caused by alcohol, drugs, and literally I can recall accidents involving racing/excessive speed of itself causing some 4 accidents.

A surprising number caused by road conditions, inappropriate speed for weather conditions, poor tyres, some fatigue often involving shift workers.

So I agree with you, that the major cause of car accidents is alcohol and alcohol/drugs, but have seen accidents where people were obeying the law but due to unfavourable conditions the car got into slides and they were unable to control them.

[prydey]

Originally Posted by asagaai

See I don't agree.

I remember riding my pushbike in the wet into Monash Uni as a student, while going round a roundabout I heard a screeching sound and turned around and there I saw this girl- who was in a slide- locked up brakes, and SHE HAD released the steering wheel and was covering her eyes and screaming.....obviously the first time she had experienced a slide in the wet and she panicked and FAILED in car control.

I was involved in a case where a lady was cruising at 100 kph along a freeway and on a curve she hit water that was running off from a public utility access road, she got into an aquaplaning slide, locked up and went sideways into an oncoming holden going at 100 kph.
.

i'm not saying things like that don't happen, but by the same token i could list off 80yr olds that have driven millions of km and never had an 'out of control' moment in their whole driving career.

i hear noise every now and then that advanced driving courses should be mandatory, but i don't agree. i guess all i'm saying is, of all the carnage on the roads, i can't see advanced driving courses reducing it by any percentage big enough to make them worthwhile.

[Express]

Originally Posted by asagaai

But, in terms of a real emergency, a person running out in front of you etc, a good driver will react and brake fast, but invariably hit too hard and lock up. A good driver will be quick to react and release and steer- but that's where abs is so good.

We are basically on the same page.

My argument though maybe not as well articulated as yours was that ABS is essential as most driver’s don’t know what to do in an emergency and will in most cases get on the brakes as hard as they can.

It’s ABS and other modern braking systems that will go a long way to help save them in these situations.

Without ABS when they hit the brakes hard they will most likely have a vehicle that is now out of their control.

Anyway I'm happy to have these systems and if there are people that don't, they'll have to start driving older cars which are a lot be fun in their own right because they require much more driver input. I just wouldn't want the roads to be full of them.


.

[asagaai]

Originally Posted by prydey

i'm not saying things like that don't happen, but by the same token i could list off 80yr olds that have driven millions of km and never had an 'out of control' moment in their whole driving career.

i hear noise every now and then that advanced driving courses should be mandatory, but i don't agree. i guess all i'm saying is, of all the carnage on the roads, i can't see advanced driving courses reducing it by any percentage big enough to make them worthwhile.

Yeah - on a cost benefit analysis you are probably right- resources would probably be better spent ensuring cars have good rubber, abs and stability control.

And ensuring drivers and not intoxicated/drugged -and I include all medications in this.

[Express]

Originally Posted by asagaai

Yeah - on a cost benefit analysis you are probably right- resources would probably be better spent ensuring cars have good rubber, abs and stability control.

And ensuring drivers and not intoxicated/drugged -and I include all medications in this.

You’re right, there are a huge range of factors that can cause an accident that doesn’t include poor car control.