4-pot brakes stop a car faster?

[Chip-mk1]

Disc size is changed for heat dissipation.

The amount of pots in the piston has nothing to do with heat dissipation.

disk size is changed for dissipation and in some circumstances to act as a larger reservoir. (dissipating heat is about re-preparing for the next application, the reservoir requirement is about being able to absorb a large enough single application during which there is little time for dissipation)

Alloy 4 pot calipers dissipate heat better than standard single piston iron calipers do, as you say its not really down to the number of pistons, its down to the material and the rest of the design.

 

[John Gordon]

disk size is changed for dissipation and in some circumstances to act as a larger reservoir. (dissipating heat is about re-preparing for the next application, the reservoir requirement is about being able to absorb a large enough single application during which there is little time for dissipation)

Alloy 4 pot calipers dissipate heat better than standard single piston iron calipers do, as you say its not really down to the number of pistons, its down to the material and the rest of the design.

This is the problem with the question posed by op. Who's to say the single pot caliper is not alloy. Too many variables.

 

[Toastfrenzy]

I know that if I change my std set up for bigger discs\pads and 4\6 pots I will be able to brake a lot harder (meaning later too) and more often than on my std set up - this is the only reason it's worth upgrading - the distance isn't necessarily shorter just moved along an equal amount (trail braking). The new setup should handle the heat more effectively (if your wheels aren't a nats coc5 away from the wheel).

 

[Chip-mk1]

This is the problem with the question posed by op. Who's to say the single pot caliper is not alloy. Too many variables.

Agreed, its just not a simple question and if he really wants to know which car stops better, wind them both upto a ton and stand on the middle pedal.

 

[MarkCup]

Agreed, its just not a simple question and if he really wants to know which car stops better, wind them both upto a ton and stand on the middle pedal.

This is exactly what I'm going to do.

100mph to zero...and film my speedometer.

Then I await someone in an ST, on standard Bridgestones, but with Mountune big-brakes, to do the same. I'm more than prepared to eat humble pie should it be necessary!

 

[Ph1 Tom]

More pistons generally means a greater pad area. Then you're onto what compounds to use...

So if the 4 pots and single pot callipers have the same pad area and compound but the 4 pots are running bigger discs then dependant on the compound they could be equally s**t!

You might find that the 4 pots have a smaller pad area so get up to temp quicker and on the first stop this would be an advantage.

Really though there's so many variables the question isn't really any use apart from getting people riled up if they are adamant that their 4 pots with bigger are superior 100% of the time in all scenarios. They're not. But they have their purpose and dependant on the conditions could be vastly superior.

 

[JD]

Presume this hasn't been answered, but neither. If everything is identical, bar the number of pistons, both should stop the car in the same amount of time/distance. My understanding of the reason to upgrade is if you can't get your tyres to break traction under braking.

I can't lock my brakes up by stamping on them. Therefore, there is potentially an amount of braking force left before the tyres break traction, that could slow me at a higher rate.

 

[Chip-mk1]

JD, it was never about everything else being even, if you look in his original post he mentioned bigger disks for example.

 

[JD]

JD, it was never about everything else being even, if you look in his original post he mentioned bigger disks for example.

Beg your pudding, must have mis-read.

 

[MG cup]

Boom

 

[Cub.]

I like 4 pot brakes because they look shiny, with nice shiny calipers.

mmmmm.......shiny.

Please carry on your technical debate, I have little more to add

 

[Nick172Cup]

I like 4 pot brakes because they look shiny, with nice shiny calipers.

mmmmm.......shiny.

Please carry on your technical debate, I have little more to add

Lol

 

[Chip-mk1]

I like 4 pot brakes because they look shiny, with nice shiny calipers.

mmmmm.......shiny.

Please carry on your technical debate, I have little more to add

bitches be dripping...

 

[BoatNonce]

If the limiting factor is your tyres, then the size of your brakes or the effort they produce beyond the adhesion limit of the tyre is irrelevant.

However there is a difference between a Civic and an ST. So one will win. I cannot be arsed to research which.

 

[Adam G]

I like 4 pot brakes because they look shiny, with nice shiny calipers.

mmmmm.......shiny.

Please carry on your technical debate, I have little more to add

White?

 

[Cub.]

White?

Even I'm not that dumb.

I did think about it though

 

[Tav]

See when you say bigger disk in the first post thats the main difference. Will a car with a bigger disk have the ability to stop faster - yes. Example my Polo with 239mm disks could only lock a wheel in the dry at say 40mph on good tyres. With the 256mm disks you could lock them up at over 70mph. Both single pistons. 256mm felt better too as initial pedal application had a large braking torque applied, which I like.

I'd only consider 4 pots for space/weight.

 

[John Gordon]

More pistons generally means a greater pad area. Then you're onto what compounds to use...

Not fully true. Pad size can be identical, the single pot poses no physically restricting attributes as to necessitate restriction of the pad size, in comparison to a caliper with more than one piston.

Distribution of force however will be a factor with the single pot, so pad pressure will be uneven. But the performance advantage will be fairly small.

 

[Ph1 Tom]

Not fully true. Pad size can be identical, the single pot poses no physically restricting attributes as to necessitate restriction of the pad size, in comparison to a caliper with more than one piston.

Distribution of force however will be a factor with the single pot, so pad pressure will be uneven. But the performance advantage will be fairly small.

I said generally. Because generally a 6 pit calliper will have a greater pad area than a 4 pot. Not always, but in general.

 

[MarkCup]

Thinking about this another way... Imagine the car is on sheet ice (like an ice rink).

Would a 4-pot setup stop you quicker?

 

[Gally]

No. Brakes can't stop physics. Ever.

 

[Gally]

Hence why I laugh at 4x4s in the winter doing crazy speeds, they seem to think they'll stop quicker.

The number of brakes pistons is irrelevant Mark. Plenty of one pot calipers out there with more stopping power than some 4 pots.

 

[kash]

Who cares, Bi*ches love 4 pots

 

[banderson]

Surely if you apply x amount of pressure on a standard setup until the abs kicks in, the abs will kick in when the same pressure is applied to a 'bigger brake setup'?

just because the brakes are bigger, the abs doesn't change

 

[BoatNonce]

We've already established that.

However the faster you go, the more force the brakes need to apply to slow you down again. Your brakes may be that powerful at 70, but they probably aren't able to lock up at 140.

 

[Dan@SJM]

I know my setup will lock the wheels at 130...

 

[BoatNonce]

I know mine lock at 70, I haven't tried any faster than that.

 

[underdog]

4 pots vs 1 pot on same size disc over one stop will be no better and may be worse if it activates abs quicker. 4 pots dissipate heat better over repeated stops. but a bigger disc is the one thing that will make a difference in stopping power and the ease it can do it in but once again will bring the abs in quicker. i guess all this as already been said but to many posts to read

 

[Bobby.]

I'm going to say 4-pots will stop quicker, because they look nicer.

 

[Chip-mk1]

4 > 1

 

[hansthebear]

4 > 1

I would just like to confirm this is a mathematical fact

 

[Wick]

Thinking about this another way... Imagine the car is on sheet ice (like an ice rink).

Would a 4-pot setup stop you quicker?

Is it a conveyor belt of ice? Is the car really a plane? Is the plane trying to take off?

 

[Sam@NP]

4 > 1

Very good.

More pots also means more modulation

 

[John Gordon]

Very good.

More pots also means more modulation

Which is why race cars started using multiple piston calipers. Better modulation and even pad pressure.

Pedal feel its much more detailed on multiple pot calipers. Its like comparing a single string guitar to a 4 string guitar, the notes you hear (feel through the pedal) are obviously going to be much more varied with more than one string.

 

[Fletcher]

I love the about of hate of here for 4 pots. IMO they are worth the money for much better brake pedal feel, and weight saving.

 

[Mr R.]

K-Sport 6 pots ftw.

 

[Midnight]

K-Sport 6 pots ftw.

Nooooooo, AP's FTW!

 

[John Gordon]

you are all wrong. Brembo monobloc. Close thread.

 

[brisa4984]

you get larger forces transmitted to the brake disc.

example.

if you apply 10 neutrons of force on the pedal area of 5 cm then the pressure is 2N/cm2
the 2 pot pistons collectively have a larger area then the pedal piston.. say 100x the surface area. So. pressure (same as pedal) i.e 2N/cm2 X 500cm2 = 1000N !

4 pot

say it is 2 x the surface area of 2 piston calliper but the pressure from the pedal piston stays the same.


if
pressure x A = F. so 2n/cm2 x 1000cm2 = 2000N

so your able to generate a larger force on the brake disc. so yes you'll stop better

if you increase the disc size. you'll have a larger pad.. so larger surface area ... So the effect is even more pronounced

 

[MarkCup]

you get larger forces transmitted to the brake disc.

example.

if you apply 10 neutrons of force on the pedal area of 5 cm then the pressure is 2N/cm2
the 2 pot pistons collectively have a larger area then the pedal piston.. say 100x the surface area. So. pressure (same as pedal) i.e 2N/cm2 X 500cm2 = 1000N !

4 pot

say it is 2 x the surface area of 2 piston calliper but the pressure from the pedal piston stays the same.


if
pressure x A = F. so 2n/cm2 x 1000cm2 = 2000N

so your able to generate a larger force on the brake disc. so yes you'll stop better

if you increase the disc size. you'll have a larger pad.. so larger surface area ... So the effect is even more pronounced

What good would that extra braking force do if you were on ice?