[adneo]

Originally Posted by Jeroen

The 2019 Fiesta in your original link above claims to have drums at the rear, even though it is over 100BHP?

Attachment 2085887




Actually, they are getting worse, a modern Fiesta apparently has a much longer brake distance than the older (by seven years).

2012: 34.7m (disc/drum)
2019: 43m (disc/drum per spec or disc/disc per Ford notes?


The plot thickens!

Jeroen

Cross posting from an old TeamBhp thread


https://www.team-bhp.com/forum/attac...ngdistance.jpg


Fiat Linea TJet - 41.1 m
Fiat Linea 1.4 Petrol - 48.8 m
Fiat Linea 1.3 MJD - 50.7 m

Originally Posted by silverado

Hitting the brakes and Praying to god! It seems like you are driving above speed limits on most occasions.I can understand you enjoying your Tjet

me.

Powerful brakes will alway help whether its at 60 or 100.You will stop earlier and without any drama.

[venkyhere]

I think the discussion is going in circles, getting too technical and intricate. Both Jeroen & adneo are talking about the same thing , bit with two perspectives. I think post #4 will shoehorn in nicely at this juncture link

[arijitkanrar]

Originally Posted by adneo

Powerful brakes will alway help whether its at 60 or 100.You will stop earlier and without any drama.

Having too powerful brakes without ABS, EBD etc. would cause the wheels to lock up potentially causing an accident.
Most brakes today (disc/drum) are more than powerful enough to lock the wheels. To control that ABS, EBD is required. This means that in most panic braking situations, the peak braking force is practically never used (because it will cause a lock up). The electronic systems will only supply enough braking force to prevent a lock up. Thus which is a stronger braking system and whether is a disc or drum is immaterial as long as the system is powerful enough. Cost and complexity are more important. And thus manufacturers choose to use drum brakes as they are less complex and cheaper than disc brakes.

[R_Gowardhan]

Originally Posted by adneo

Dont you guys think both manufacturers and the customers start looking at such safety aspects more critically than going hyper over sunroofs, touchscreens etc?

I would happily buy a car with a generic audio system with Bluetooth, without sunroof and rather have such safety features along with a rear independent suspension if the makers are generous enough to throw one in.

We live in a country where people ride two-wheelers wearing masks but don't bother wearing a helmet in-spite of the fact that CoVid-19 has claimed 1.35 Lac lives so far but 1.51 Lac people were reported to have lost their lives in road accidents last year alone. Sunroofs in India should be renamed Brain-less Roofs / Suicide Roofs as most people want it in their cars to stick out their heads (ignoring personal safety and law) rather than to subtly enjoy a well lit and airy cabin. As for the large touchscreens, I personally upgraded my regular OEM stereo to a 10 inch screen 6 months back and I must admit that it is a HUGE distraction and Irritant while driving. The only useful function of a screen inside of a car is for reverse camera.

When I upgraded from Ritz (non ABS) to Jazz (ABS and well calibrated brakes), I could see a world of difference in the braking character from day 1. I can only imagine how an all-4 disk brake car would further enhance the experience by inspiring further confidence.

But I am not too hopeful that we will get many all-4 disk brake cars even as options anytime soon unless the rules mandate it. Most manufacturers are inclined to develop and sell India specific models (Low on safety - High on feature - Cheaper on cost) and happily ship them to other developing countries (Latin America , SA etc) where either the rules are lax and the customers do not protest either.

[sumeethaldankar]

Pardon me but I am the technically inept here. Dosen't the ABS has some channeling feature single channel, dual channel something? And doesn't it work better if there discs all around rathern than just drums which makes it a single channel ABS or something?

[vj_torqueaddict]

Originally Posted by adneo

The second feature which comes really handy in such situations is autonomous brake assist or whatever they call it, basically the radar driven brake assist which applies the brakes automatically to avert a collision. Due to multiple factors a driver could have missed the car which jumped out of the bus lane, ranging from bad headlights to heavy rain fall. Its also just not limited to cars since Indians love crossing the road recklessly and we always have to watch out for people jumping out of the median on to the fast lane.

Excellent post! Thanks for opening this discussion. Not sure if this point has been already discussed in this thread, but laws in India are strict w.r.t radar tech. Please refer this page - https://dot.gov.in/sites/default/fil...20Industry.pdf

There are case studies done by Maruti and Benz as per the article above.

There was a thread on Team bhp as well where Indian govt did consider lifting this restriction : https://www.team-bhp.com/forum/india...ay-lifted.html (Restrictions on automotive radar tech may be lifted) . This was closed as nothing concrete emerged.

[buntee90]

Originally Posted by adneo

Hi All,
One of my biggest grief when it comes to Indian Car manufacturers is how every single one of them try to skimp on important safety features and provide more gizmos and toys instead.


I would happily buy a car with a generic audio system with Bluetooth, without sunroof and rather have such safety features along with a rear independent suspension if the makers are generous enough to throw one in.

Local manufacturers(esp Koreans) are trying to give features which usually come in premium segment cars costing upwards of 30-40 Lakhs (Cooled seats, panoramic sunroofs, big displays for MID and infotainment). But the thing is (most of) these premium offerings have solid mechanicals first and gizmos later.

Most of the Indian manufacturers are going the easy and arguably cheaper way; install sunroofs, give a lot of bling, wireless charger etc.
Improving on the mechanical and safety front involve a lot of hard work and R&D costs $$$ which sadly only a handful of manufacturers are willing to do.

Originally Posted by Mad Max

We, as TBHP members, are a declining minority, IMO. Some people just want to make sure they showcase their worth via ostentatious displays. And cars, for one, are the perfect display of wealth. You can even take it to others homes and display your worth!

Well I certainly hope not! BHPians certainly have some positive effect on people and helps them make an informed decision.

[sagarpadaki]

The first gen i20 and the facelifted i20 came with discs all around on higher variants. We have the variant with all 4 discs hence I know the braking well. I drove the lower variant with drum at the rear a couple of years ago and I could sense/feel lesser braking at >80 kmph speeds. The urgency to shed speed was lesser on the rear drum variant v/s rear disc. Now before someone asks if the load was similar, tyres were same between the cars, let me clarify. Yes, they were different. However, I have driven our i20 with varying loads at different speeds. Hence I know the braking in different scenarios.

However, at speeds lesser than 80 kmph, I could not see a tangible difference between the disc vs drum variant

[TorqueIndia]

Contrary to the popular belief , here is a test data of Baleno RS equipped with RR disc brake and Baleno NA with drum setup. The stopping distance of RS version is much higher than that of NA , curious on it !

https://youtu.be/39QZ_Ld4SZs

[Jeroen]

Originally Posted by TorqueIndia

Contrary to the popular belief , here is a test data of Baleno RS equipped with RR disc brake and Baleno NA with drum setup. The stopping distance of RS version is much higher than that of NA , curious on it !

Its 3,40m more, just about 12%. But it still makes for an interesting case. I wonder if that Baleno has more weight up front with its bigger engine?

Do we know what the difference are between these cars? Weight, chassis/suspension (shocks/springs) tyres etc.

All these factor do come into play.

Jeroen

[adneo]

Originally Posted by Jeroen

So nice of you.

You’re looking at it from the wrong angle. It is not about disc over drums. It is purely about cost cutting.

I you would find two identical cars, one disc/drum and one disc/disc and you would find the disc/drum would have a larger stopping distance you can not conclude drum brakes are inferior and lead to larger stopping distance.

The appropriate conclusion is they fitted under dimensioned drum brakes! So they were cheap in the first place, to install drums, and then they notched up their cheapness by installing too small ones! It is not so much a technology or engineering or design issue, it is purely a cost cutting issue.

if they fitted really tiny disc at the rear they could perform less than the normal drums too.

On small light cars, rear drums can be perfectly adequate. No problems with my wife’s Ford Fiesta.

My 1974 Royal Enfield bullet has drum brakes, will not stop at all. Not a drum brake issue as such, but it is just impossible to install large enough drum brakes to get a comparable braking to disc brakes.

To put it in a different way: A disc brake gives superior braking performance compared to drum brake, when comparing the weight of the brake to brake performance. That is it single most important criteria. You get better stopping performance per kilogram of installed brake!

For the same weight near your wheel you can get far better braking performance. Or for less weight the same!

Everything else, is accounting.


Jeroen

I guess we are finally converging towards a similar conclusion.

Lets say for the purposes of this debate we put target Braking distance from 100 - 0 at 40m

If a small hatch back given its light weight is able to stop within 40 m from 100 kmph with a rear drum then we are all happy.

Now i would like summarise a couple of points from your inputs :

1. Disc brakes provide more braking force per kg of brake installed. So for clarity, i would say in very layman terms and hypothetical figures that the braking force of a 50 mm disc brake can be matched by a 100 mm drum. But both will provide the same braking force.

2. With the Royal Enfield example you have also highlighted 2 things:

a. Based on the weight of the vehicle the required braking force may be higher than usual.

b. So if the RE requires X unit of braking force to maintain that same 40 m of braking distance and that equates to a 300 mm Drum brake which is not feasible or installable, means we would have to look at either settling for a higher braking distance with a <300 mm Drum setup or go for a Disc setup which can offer the same X unit of braking force over a 150 mm Disc.

Now the scenario which causes me grief is the following :

Manufacturer's UK Division designs a Sedan with more than 1 ton of kerb weight. Decides to maintain 40 m braking distance following which calculates that in order to maintain the required brake bias, dynamics etc the rear braking force required is X and that can be provided by either a 300 mm Drum or a 150 mm Disc.

Since it's not realistic or feasible for N number of other parameters to install
300 mm Drums on the rear axle, its imperative that in order to maintain the same braking distance the 150 mm Discs have to be installed on the rear axle.

Now the Manufacturer's India division in their conquest to increase profits and cut corners, figures out no one is really bothered about the braking distances in India as long as they throw jargon like ABS,EBD etc at the Mango men. They decide to swap the 150 mm rear Discs with 200 mm Drum thereby immediately reducing the rear braking force from the originally designed X unit to Y unit where Y<X . As a result, the braking distance goes up from the designed 40 m to 50+ m.

Please note all dimensions of the Drums, Discs are purely hypothetical and i have just used them to simplify the message.

Originally Posted by Turbanator

Call me whatever, the first thing I do is to switch off this assistance on the Merc. It's programmed for countries where people know the difference between roads and their backyards, not for us, at least in the current day. The moment it sees a human being coming on a road, it brakes as if it's the end of the world.

This sounds like those instances I had run into where I saw people run their car with disabled passenger side Airbags saying the slightest impact would result in huge repair charges due to airbag deployment. For someone like me, i would rather have it on than regret later. The sensitivity of all such autonomous or assistance aids are tweakable and we should be able to configure them to give us the required assistance rather than being over intrusive. For eg. I had a fellow TJet owner crib about how mad the rain sensing wipers were, now he is only full of praises about it once I showed him how to set the desired sensitivity levels.

Someone had mentioned about people jumping in the front just for kicks, that's equivalent to saying people hitting the front bumpers and headlights to get kicks out of airbag deployment. The point is once it becomes the norm people won't be too bothered to indulge in such nuisance. And for the odd ones out there. Once the vehicle stops just walk up to them to show the video of the failed Volvo automatic brake test, where the car hits the Top Exec. That will definitely set them straight.

I think these are features which I would rather have and depending on situation either chose to utilise or not utilise, over having stupid gimmicks like sunroofs in a tropical country and bigass touchscreen because firstly that's a real distraction while driving, secondly passengers have their own phones and devices for entertainment. If we have survived so long referring to GMaps using 5 inch phone screens I would say thats enough for its purposes.

[Jeroen]

Originally Posted by adneo

I guess we are finally converging towards a similar conclusion.

Agree.

Originally Posted by adneo

Now the Manufacturer's India division in their conquest to increase profits and cut corners, figures out no one is really bothered about the braking distances in India as long as they throw jargon like ABS,EBD etc at the Mango men. They decide to swap the 150 mm rear Discs with 200 mm Drum thereby immediately reducing the rear braking force from the originally designed X unit to Y unit where Y<X . As a result, the braking distance goes up from the designed 40 m to 50+ m.

Your example is similar to what is being discussed in some other threads, where apparently cars for the Indian markets have less crash protection then the same models being exported.

But just to push the envelop here on some thinking: The manufacturer could also choose to install bigger disc all round and decrease the braking distance from 40 to 30m

At what point does cost cutting become meddling with safety? Every single car out there can be improved on braking distance, if you throw some money at it!

Whether manufacturers actually think like you illustrate in the above example I can’t comment on. As mentioned, as soon as you have ABS/EBD and all the other abbreviations installed, the type of brake becomes less relevant anyway.

What would be interesting to understand is what the formal brake distance requirements are in India. And how do cars stack up against those?

Because if anything, there should be at least one norm, which is the legal norm to comply with. So if your car complies with the legal braking distance norm would you still consider it cost cutting. How much better does a car need to do than the legal brake distance before we don’t consider it cost cutting anymore.

I understand the thought about cost cutting impairing safety. To my earlier point, if you want to accuse somebody of impairing safety, you also need to specify what the norm is. If the norm is met, it is ok. How much above the norm? Looks good in the brochure, but it can’t be demanded.

So the crucial question remains: What are the legal brake distances in India and how do cars stack up against them. If they meet the legal requirements, you need to talk to your politicians first and foremost, not the car manufacturers.

You can not be accused of cost cutting if you stay well within the legal norms I would think? So who has insights into the formal brake distance requirements?

Jeroen

[adneo]

Originally Posted by Jeroen

.

What would be interesting to understand is what the formal brake distance requirements are in India. And how do cars stack up against those?

Because if anything, there should be at least one norm, which is the legal norm to comply with. So if your car complies with the legal braking distance norm would you still consider it cost cutting. How much better does a car need to do than the legal brake distance before we don’t consider it cost cutting anymore.

I understand the thought about cost cutting impairing safety. To my earlier point, if you want to accuse somebody of impairing safety, you also need to specify what the norm is. If the norm is met, it is ok. How much above the norm? Looks good in the brochure, but it can’t be demanded.

So the crucial question remains: What are the legal brake distances in India and how do cars stack up against them. If they meet the legal requirements, you need to talk to your politicians first and foremost, not the car manufacturers.

You can not be accused of cost cutting if you stay well within the legal norms I would think? So who has insights into the formal brake distance requirements?

Jeroen

Now this is where things become grey. The entire automotive norms have been heavily rigged by the automotive cartel in India and its most of the times tailored made so that pathetic greedy manufacturers like Maruti Suzuki sitting on shit loads of cash reserves can get their unsafe cars cleared out in terms of compliances.

So in a nutshell even though these safety features might not be the legal mandate, an aware customer and burning market demand will definitely push the manufacturers come up with the same offerings at par with their global models.

Let people decide what they want interms of gizmos but dont let an unsuspecting customer pick up a less safe car by luring him with gizmos. Keep the core strengths same across the board and then let people decide what works best for their budget.

[GeeTee TSI]

It is psychological probably, but in 2020 to have cars costing more than 20L (Innova comes to my mind) sporting rear drum brakes gives me a feeling of Indian consumer being ripped off.

This gives a similar creepy feeling like crash tests where somewhere something is downgraded for India which the OEM would dare not touch had it been another market!

[Jeroen]

Originally Posted by adneo

Now this is where things become grey. The entire automotive norms have been heavily rigged by the automotive cartel in India and its most of the times tailored made so that pathetic greedy manufacturers like Maruti Suzuki sitting on shit loads of cash reserves can get their unsafe cars cleared out in terms of compliances.
.

I doubt that very much. I did a bit of googling and there are some documents out there showing pretty detailled braking requirements. Much more than just braking distance by the way. Also, I noticed the braking distance was not given, but specified in decelerations time, which is probably a much better criteria anyway. (https://law.resource.org/pub/in/bis/...852.8.2001.pdf) But it is dated though.

Would love to hear somebody who could really dig up the most recent versions of these Indian documents and lets do the math.

But for lack of anything concrete lets take the UK highway code. Which does specify braking distance. (not to be confused by stopping distance). See https://www.rac.co.uk/drive/advice/l...ing-distances/



If I compare these table to the stopping distance tables you posted earlier you will see that nearly all cars in your table comply with current UK Highway Code!

You really think you need more stringent requirements? Almost all your cars comply with modern Western European Brake Distance requirements. What is the problem?

Jeroen