Split thread: Older cars and safety

[Bad Bird]

I said nothing about abs.

[Barry_v]

Originally Posted by UNR8D

My point was an overall better brake package

I think you're just struggling to find any real difference to speak of, so you're now going to try and put this 'black and white' difference down to magic.

Originally Posted by UNR8D

its about FACTS ffs... its proven beyond reasonable doubt that new cars crash better than old cars.

err.. so why didnt you argue that point instead of rubbishing an XC falcon's steering and braking?

you made a stupid statement and we called you on it, deal with it.

[Barry_v]

Originally Posted by Bad Bird

The funny thing is, most people don't realise that number of piston calipers is irrelevant for brake force.

I understand what you're saying, but in the case of EL-AU I believe the total piston area was increased (to match the slightly larger diameter disc). but I agree that going to twin piston calipers certainly didnt make a huge difference.

[geckoGT]

Originally Posted by xy500

You might want to do some research to as to just how braking surface area and number of caliper pistons actually improve braking, you might be surprised when your 80-0km braking distance doesn't change substantially.
And it's braking, not breaking (that's what you were just saying the new brakes don't do...)

You may want to read through this test
AFF brake test

It seems you may be wrong. These were the same class of car from the same model, the only difference is the size of the brakes and in general the large brakes out performed the smaller.

I also find it interesting that a statement was made that larger brakes require more clamping pressure to be as effective in a single brake application and that apparently as new cars came out this clamping pressure has not increased. Then in the same post it was stated that new cars have larger brake boosters to give a lighter pedal feel. Which way is it? If I have a larger and more powerful brake booster in my new car than an old car, would I not apply more clamping pressure at the calipers if I apply the same level of pedal force? It seems to me that new cars do apply more clamping pressure and I doubt anyone can really dispute that.

So, lets look at some hard figures in terms of old and new brakes, but lets compare apples with apples and look at the XC Cobra Hardtop and the FG GT. I have selected these because these are the performance models of the respective years and as motoring enthusiasts this is what we should be talking about.

XC Cobra Hardtop

Kerb mass = 1498 kg
Front brakes = 286 mm ventilated with single piston calipers
Rear brakes = discs, unknown size and ventilation
Tyres = Difficult to find for cobra, only details I can find for XC is 6" pressed steel safety rims (globe alloys for cobra) and 185 x 14 tyres.

FG GT (without brake upgrade options)

Kerb mass = 1852 kg
Front brakes = 355 mm ventilated with 4 piston calipers
Rear brakes = 328 mm ventilated with single piston calipers
Tyres = 245 x 19

So you can see in the comparison here that the XC is 354 kg lighter (not the approx 500 kg some here have stated, a XC is not 1300 kg) or what is approx 23.63% lighter. Front brakes of the FG are 24.125% larger on the front with a much larger pad surface area and rotor thickness. Rear brakes are unknown at this stage but I think it is safe to say the rear brakes are much larger on the FG. Now before you say that rear brakes do not matter as 30% of the braking is on the rear and 70% is on the front, that is a general rule but suspension will affect that and not many will argue that XC suspension is better than FG.

Lets also look at the tyre (which by your admission is the limit of all brakes). The XC from what I can find has 185 width tyres, the FG has 32% more at 245. Therefore the FG has more grip which allows more of the available braking power to be used.

I think it is pretty clear from this that the FG will out brake the XC not only in single emergency brake application but also in repeated brake applications with no trouble, to suggest otherwise is crazy.

Now, lets get back on topic (which was pre 80's car compared to a new hatch) and compare the performance car of the time to a performance hatch now.

XC Cobra Hardtop

Kerb mass = 1498 kg
Front brakes = 286 mm ventilated with single piston calipers
Rear brakes = discs, unknown size and ventilation
Tyres = Difficult to find for cobra, only details I can find for XC is 6" pressed steel safety rims (globe alloys for cobra) and 185 x 14 tyres.

Mini Cooper S R56

Kerb mass = 1105 kg
Front brakes = 297 mm ventilated rotors twin piston calipers
Rear brakes = unknown, single piston calipers on solid disc
Tyres = 205 x 17

So the Mini is 73.76% of the mass of the XC, yet it has 3.8% larger front brakes and 10% larger tyres. Not hard to see which one will out brake the other there.

I can illustrate this point in personal experience. At a club skid pan day we did a braking exercise from 60 km/h and then 80 km/h on a wet surface. Our Mini (yes we took the Mini for something different) managed to pull up quicker than all the Fords including BA XR8's and a BF Typhoon. The Mini was the car that had the shortest stopping difference, by a considerable margin. Even the instructor was surprised and said that in an emergency brake he would prefer to be in the Mini.

I am sure if you went to the hassle of finding the information on other hatches and compared them to pre 80's cars of similar performance levels (so no WRX against Falcon 500 or vice versa) you will find that the newer cars generally have more braking capacity. Personally I can not be bothered doing this and it is time for the other side of the debate to actually do some research rather than just giving opinion and unsubstantiated statements.

As for the statement a while back that "threshold braking and ABS do not mix", absolutely incorrect. Threshold braking and ABS mix very well, find the threshold point well and you will pull up fast, go too far and ABS will take over. The process of applying half pedal pressure until weight transfer has happened and the tyres are loaded up, then squeezing on more pressure until the tyres are bordering on slipping (threshold braking) can be done with a ABS vehicle. It is pulse or cadence braking that should not be done with a ABS equipped vehicle. They are two ways of doing the same effect except ABS can cycle many times faster than your leg and is therefore more effective. ABS can not operate properly if you pulse brake as you keep releasing brake pressure.

[geckoGT]

Originally Posted by Barry_v

on another note, its hilarious that new falcons still dont have ventilated rear discs like disc brake XCs.

Not really, the non ventilated rear brakes on modern falcons are now only on lower spec (non performance models), the high spec performance models have 328 mm ventilated rear rotors. Now lets compare apples with apples, the non performance XC models had drum rear brakes, it was only the performance models, e.g cobra that had discs, that were no doubt a lot smaller than 328 mm considering the fronts were a lot smaller than that.

So I see a clear improvement in new over old when you compare equal models, but don't let the truth get in the way of a good story.

[xy500]

so professor breaks has let us know that bigger brakes will always stop you faster, no matter what. It has nothing to do with wider rubber apparently. I find comfort knowing it wasn't you who designed any of the cars on the market. If you want a fair comparison between the two brakes, put the same rubber on both cars and then take them to the skid pan.

[UNR8D]

Originally Posted by Barry_v

I think you're just struggling to find any real difference to speak of, so you're now going to try and put this 'black and white' difference down to magic.

im not the one struggling here...

err.. so why didnt you argue that point instead of rubbishing an XC falcon's steering and braking?

you made a stupid statement and we called you on it, deal with it.

compared to the NC or my Lexus it was/is RUBBISH, dosent mean I dont like the car but facts are just that fact.
It was a play on words to get a point across.

Interesting how you can have a point of view, but when it goes against your way of thinking its time to find the pitchfork.

[UNR8D]

Originally Posted by xy500

so professor breaks has let us know that bigger brakes will always stop you faster, no matter what. It has nothing to do with wider rubber apparently. I find comfort knowing it wasn't you who designed any of the cars on the market. If you want a fair comparison between the two brakes, put the same rubber on both cars and then take them to the skid pan.

It was 12 at night and I made 1 spelling mistake, do you feel like a big man you picked up on it..

but by that exact theory your car is then modified so not apple's vs apples then is it ;)

[geckoGT]

Originally Posted by xy500

so professor breaks has let us know that bigger brakes will always stop you faster, no matter what. It has nothing to do with wider rubber apparently. I find comfort knowing it wasn't you who designed any of the cars on the market. If you want a fair comparison between the two brakes, put the same rubber on both cars and then take them to the skid pan.

What are you on?? Please do not give any out as it is way too powerful.

The discussion is about stopping ability of old versus new, not brake size (brake size comes into with other factors). A very correct point stated tyres comes into as the limit of all braking power (I agree huge brakes are no use without grip for them to work on). I pointed out in the spirit of the topic that new cars achieve better stopping distances through not only bigger brakes but more grip too.

I am sure you do not have to be "Professor Breaks" (or should that be Professor Brakes) to understand that.

[Boosh Brus]

http://www.youtube.com/watch?v=ly62FoZH_Dc

Pffffttt ABS what an evil marketing ploy.

[geckoGT]

Originally Posted by Boosh Brus

http://www.youtube.com/watch?v=ly62FoZH_Dc

Pffffttt ABS what an evil marketing ploy.

Not sure what you mean here.

Yes a well practiced driver can use threshold braking to out brake a full ABS stop, that is without doubt and I have proved that on skid pans in my advanced driver training. In a Mercedes ambulance using threshold braking I can stop slightly shorter than I can if I just bury the foot and let ABS do the work. The difference is only about a metre and an impact at that point is a bump that would really only knock a pedestrian off their feet, maybe break a leg.

The problem is that threshold braking is a skill that requires instruction and a lot of practice in the individual vehicle, change the vehicle and the threshold changes requiring more practice. The simple fact is that most motorist simply do not have the skills to learn this in all the vehicle that they may drive. Get the threshold wrong and induce full lock and the distance is a lot more in braking distance, enough to be a fatal impact on a pedestrian.

So yes, I will concede that in the right circumstances a non ABS car (with all other brake characteristics being equal) may out brake a ABS application. The limiting factor here is all the right circumstances being in place are rare.

[Boosh Brus]

The videos conclusion was:
1.) Threshold breaking rocks
2.) ABS is awesome but not as rocking a threshold breaking and;
3.) non ABS compared with ABS - "but this time I disabled the ABS system in my car... you can see the braking distance has dramatically increased.... I have no control over my steering"

The average driver is not a professional racing driver.

[UNR8D]

Originally Posted by Boosh Brus

The videos conclusion was:
1.) Threshold breaking rocks
2.) ABS is awesome but not as rocking a threshold breaking and;
3.) non ABS compared with ABS - "but this time I disabled the ABS system in my car... you can see the braking distance has dramatically increased.... I have no control over my steering"

The average driver is not a professional racing driver.

What? So you’re agreeing that ABS is better for the average driver, as in an emergency stop you can mash the brakes and still maintain full control of the vehicle, where as in a non-abs equipped car you simply don’t have that option?

If you take note of my previous posts I have also said ABS won’t stop you any quicker, but it allows control of the vehicle in an emergency brake situation.

ABS allows you to stand on the brakes 100% and then use all brain power to make suitable decisions to avoid an obstacle or make it less painful, and in addition to that most ABS now days has BA (brake assist) which gives full brake assistance in an emergancy stop bridging the gap between threshold braking and simple ABS.

[Boosh Brus]

Originally Posted by UNR8D

If you take note of my previous posts I have also said ABS won’t stop you any quicker, but it allows control of the vehicle in an emergency brake situation.

No in the example above the car with ABS stopped in a shorter distance then with ABS disconnected. The extra control was a bonus.

The average Joe wont be threshold breaking when the roo jumps out.

[UNR8D]

Originally Posted by Boosh Brus

No in the example above the car with ABS stopped in a shorter distance then with ABS disconnected. The extra control was a bonus.

The average Joe wont be threshold breaking when the roo jumps out.

ahh ok, makes more sence and yes I do agree.

[Boosh Brus]

Might not always be the case but locked wheels suck and are not helpful when trying to stop.

In the basic RTA motorcycle training they teach you how to avoid locking wheels. Its a shame there is no emergency breaking test for cars.

[geckoGT]

Originally Posted by Boosh Brus

Might not always be the case but locked wheels suck and are not helpful when trying to stop.

In the basic RTA motorcycle training they teach you how to avoid locking wheels. Its a shame there is no emergency breaking test for cars.

It is the same in WA, they teach you about applying the front brake to load up the front wheel with the weight and then once weight has transfered and the front tyre has max grip, then squeezing on more brake to maximum braking. Not only do they teach you this but they also test you on this and you have to be able to pull the bike up in a minimum distance from a set speed.

I agree, this should be a part of a car license as well.

[Barry_v]

Originally Posted by UNR8D

compared to the NC or my Lexus it was/is RUBBISH, dosent mean I dont like the car but facts are just that fact.
It was a play on words to get a point across.

Interesting how you can have a point of view, but when it goes against your way of thinking its time to find the pitchfork.

that isnt a fact, thats your opinion - which quite frankly defies common sense when you realise the following:

the NC's disc brakes system is nigh on identical to an XC disc brake system. All the components could practically be interchanged. If you think one is rubbish compared to the other, your **** meter needs recalibrating.

For the record I have a 1979 P6 LTD (ie an XC LTD) and my previous car was a 92 DC LTD (NC LTD). Having worked on both brake systems I know there isnt any magical upgrade that occured. Both even have the crap disc brake handbrake. I owned both at the same time for a few years and can assure everyone to there being no measurable difference in stopping power.

not going to argue with you any further, people can judge themselves which one of us is talking rubbish.

[geckoGT]

Originally Posted by Barry_v

that isnt a fact, thats your opinion - which quite frankly defies common sense when you realise the following:

the NC's disc brakes system is nigh on identical to an XC disc brake system. All the components could practically be interchanged. If you think one is rubbish compared to the other, your **** meter needs recalibrating.

For the record I have a 1979 P6 LTD (ie an XC LTD) and my previous car was a 92 DC LTD (NC LTD). Having worked on both brake systems I know there isnt any magical upgrade that occured. Both even have the crap disc brake handbrake. I owned both at the same time for a few years and can assure everyone to there being no measurable difference in stopping power.

not going to argue with you any further, people can judge themselves which one of us is talking rubbish.

True they are the same size brakes at 286 mm front and rear ventilated but the vehicle mass is different, kerb mass for the P6 is 1832 kg and the NC is 1672 kg so I doubt with the extra kerb mass that the P6 would pull up as well as the DC but in size of brakes they are the same yes.

Compare it to the other examples that I gave and the P6 will do worse than the Cobra as the P6 is 334 kg heavier, it is just a question of maths and physics.

[svo supporter]

UNR8D. Mate, take a front wheel off your ABS equipped car and stick your head near the strut. You'll see a wire there, which goes to a sensor, which points to the back of the hub. Break your sensor wire , drive down the road and jam the brakes on. Then come back on here and say, that particular corner didn't lock the brake. (Complete with a vid of the test of course) Then I'll gladly replace the sensor out of my own pocket. (It costs a couple of hundred dollars too)

DAVWAY. Mate, stick your head underneath a heap of cars and look at tyres. I happen to have to do this every day of the week and the crap I see on modern cars is unbelieveable and they say, "she'll be right" or "I've got no money". These tyres have either got wire hanging out, or they are legally bald. Strangely enough, the older car drivers are willing to dig into their pockets just to make sure the tyres are in legal condition, so that's one less thing for coppers to pick on them for. They might only be recaps, but at least the tread is legal, even if they don't like recaps.

But hey, what would I know. I only play with wheels and tyres for a living. or as I commonly say, a dumb tyre fitter

[geckoGT]

Originally Posted by svo supporter

UNR8D. Mate, take a front wheel off your ABS equipped car and stick your head near the strut. You'll see a wire there, which goes to a sensor, which points to the back of the hub. Break your sensor wire , drive down the road and jam the brakes on. Then come back on here and say, that particular corner didn't lock the brake.

DAVWAY. Mate, stick your head underneath a heap of cars and look at tyres. I happen to have to do this every day of the week and the crap I see on modern cars is unbelieveable and they say, "she'll be right" or "I've got no money". These tyres have either got wire hanging out, or they are legally bald. Strangely enough, the older car drivers are willing to dig into their pockets just to make sure the tyres are in legal condition, so that's one less thing for coppers to pick on them for.

But hey, what would I know. I only play with wheels and tyres for a living. or as I commonly say, a dumb tyre fitter

The thread is talking about the cars, not the owners. If we started on that line then we could all start posting pics of 1970's rust buckets that would explode in a cloud of powder rust particles in various places if they hit a pot hole too hard. Now that would not be fair would it, I am quite sure more old cars will have significant mechanical faults than new cars?

I do not see all that as valid points to the debate, lets compare apples with apples, not apples with lemons.

[svo supporter]

Originally Posted by geckoGT

The thread is talking about the cars, not the owners. If we started on that line then we could all start posting pics of 1970's rust buckets that would explode in a cloud of powder rust particles in various places if they hit a pot hole too hard. Now that would not be fair would it, I am quite sure more old cars will have significant mechanical faults than new cars?

I do not see all that as valid points to the debate, lets compare apples with apples, not apples with lemons.

I understand it's about cars and not the owners, however if you look back at page 9 of this thread, you'll see some comments directed at me. UNR8D posted a diagram up, insinuating that a particular wire didn't exist whilst DAVWAY is insinuating I'm crapping on, when it comes to older cars not being looked after as well as newer cars.

As for mechanical faults. Much for much ness, from my job. I do admit, I'm no roadworthy inspector, however I have commented from what I have seen from my employment stand point. If people want to believe it, good, if not, no skin off my nose. However, before saying I'm full of it, with what I have just posted, go stick your head around and use your own 2 eyes first.

[geckoGT]

Originally Posted by svo supporter

I understand it's about cars and not the owners, however if you look back at page 9 of this thread, you'll see some comments directed at me. UNR8D posted a diagram up, insinuating that a particular wire didn't exist whilst DAVWAY is insinuating I'm crapping on, when it comes to older cars not being looked after as well as newer cars.

As for mechanical faults. Much for much ness, from my job. I do admit, I'm no roadworthy inspector, however I have commented from what I have seen from my employment stand point. If people want to believe it, good, if not, no skin off my nose. However, before saying I'm full of it, with what I have just posted, go stick your head around and use your own 2 eyes first.

I do see what you are saying but in my job I also see a lot of cars and I have to say that I see many more "death trap" cars that are 15 years old or older, than I do those under 5 years old.

I never said you were full of it, if I did please show me the quote. I just said the comparison was not really relevant to the discussion, that is not saying you are full of it.

As for the broken ABS wire, everyone that has had one break please put your hand in the air? Out of all the cars I have had with ABS and all the ABS vehicles I have driven, over 100,000's of km's, not one has broken.

It does not change the fact, break one of those wires (if you are unlucky) and the brakes still operate as older pre ABS models do.

[WMD351]

Originally Posted by svo supporter

Mate, take a front wheel off your ABS equipped car and stick your head near the strut. You'll see a wire there, which goes to a sensor, which points to the back of the hub. Break your sensor wire

Yep, I'm curious to know how often these wires break.
Are you trying to argue that no chance of ABS is better than some chance?

[geckoGT]

I did a search for "broken abs sensor wire" as that is the phrase I think is more likely to be mentioned at least once in a post or article, 297 hits worldwide. Drop the sensor out of the phrase to "broken abs wire" and you get 1500 hits.

To me that means it is not a frequent occurrence and many of the ones I saw were to do with 4WD (probably ones that go off road, they do exist). Do a search for "timing chain rattle" and you get nearly 400,000 hits.

Personally I think if this wire was vulnerable enough to consider a safety risk it would have to attract millions of hits to show it was a common problem.

[Nikked]

SVO supporter is clutching on straws. Got nothing at all.

[UNR8D]

The same black wire that has never failed after all the punishment ive given my cars? the same black wire that doesn't just break on any 4x4 crossing some of the crappiest roads known to man? same black wire that despite coil overs and some of the crappiest roads out west has just *not* broken on my Lexus?

They don't just break, I want to know how many of these so called wires break on a regular occurrence rendering 1000's of abs equipped cars.......well not any worse off than a non abs equipped car.

Its a MUTE point why are you arguing about this?

[Barry_v]

Originally Posted by geckoGT

True they are the same size brakes at 286 mm front and rear ventilated but the vehicle mass is different, kerb mass for the P6 is 1832 kg and the NC is 1672 kg so I doubt with the extra kerb mass that the P6 would pull up as well as the DC but in size of brakes they are the same yes.

If you're going to get that nitty picky with the kerb weights (which i wouldnt trust anyway, when you put a car on a weighbridge its often no where near the quoted figure) etc.. you could argue that an XC will theoretically outbrake the NC because it is lighter yet has the same brakes. in reality I doubt there would be any measurable difference. even a few hundred kilos either way is a pretty subtle thing to notice.. I can't say i've noticed the brakes suddenly becoming ineffective in any car just by having a couple of passengers.

[geckoGT]

When I drove over to Brisbane from WA in my XR8 (BA) I had it fully loaded with a heap of gear, two bikes, full boot, full backseat etc. It was at least 200 kg and I could feel it. I know I can feel it in a car when it is 200-300 kg heavier, both in braking and handling

300 kg was the weight loaded into the back of that yellow commodore for the crash test that featured before, you know the one that completely disintegrates. 300 kg is a lot of mass when you have to pull it up.

[Barry_v]

Originally Posted by geckoGT

When I drove over to Brisbane from WA in my XR8 (BA) I had it fully loaded with a heap of gear, two bikes, full boot, full backseat etc. It was at least 200 kg and I could feel it. I know I can feel it in a car when it is 200-300 kg heavier, both in braking and handling

300 kg was the weight loaded into the back of that yellow commodore for the crash test that featured before, you know the one that completely disintegrates. 300 kg is a lot of mass when you have to pull it up.

I seriously have no idea where you're going with this... I've demonstrated that an NC and an XC have identical braking systems and the you've said the XC is lighter. I did this because UNR8D insinuated that there was a huge difference between the two.

are you saying I should be able to percieve a difference in braking capacity between a DC and a P6 because one is (according to the magic interwebs) a mere 160kg heavier. Sorry, my spidey sensors arent that good.