Sneak peek at my latest mod..

[horgantrevor]

How much did they cost?

yes

 

[Alps]

Very nice ALx, another great mod coming on!

 

[Alex]

if you dont mind me asking what are you putting them on too is it a ML

and also how much ?....

have you a link to site

and i think a set would look great on my w202

How much did they cost?

Not cheap

 

[NW_Merc]

Not cheap

C'mon stop being coy

 

[Dieselman]

How does having more pistons increase the stopping ability? Surely that is governed by the friction coefficient between the tyre and road surface.
I appreciate how it may affect brake pedal feel.

As this is a front brake mod only, as more force transfers to the front brakes might that not upset the brake balance and cause instability and possibly reduced stopping performance overall?
Also if the calliper now has a greater operating area does the master cylinder not need increasing in size to accommodate the greater fluid flow?

 

[Alex]

How does having more pistons increase the stopping ability? Surely that is governed by the friction coefficient between the tyre and road surface.
I appreciate how it may affect brake pedal feel.

As this is a front brake mod only, as more force transfers to the front brakes might that not upset the brake balance and cause instability and possibly reduced stopping performance overall?
Also if the calliper now has a greater operating area does the master cylinder not need increasing in size to accommodate the greater fluid flow?

12-pot calliper piston area is almost exactly the same as that of a Brabus 6-pot calliper. The technological advantage of the former is in more even pressure to the pad delivered from the 12 identical pistons.

The kit is for the front and back, hence two pictures in my first post. The fronts are 12-pot with 375mm rotors, rears are 4-pot with 355mm rotors. There's no upsetting the balance.

Depending on the model of the car they are designed for, this and other Alcon/Brabus brakes are meant to work with OE master brake cylinders.

 

[bolide]

How does having more pistons increase the stopping ability? Surely that is governed by the friction coefficient between the tyre and road surface

Yes, remind us again how the presence of lots of pistons in the caliper makes a car stop faster?

They do look nice, though

Nick Froome
the independent Mercedes Estate specialists

 

[flango]

I thought Alx explained it perfectly. by having 12 pistons ( 6 x per pad) you exert a much more even pressure between the pad and the rotor. This means that the friction material on the pad is in much more uniform contact with the rotor resulting in greater resistance making the car stop quicker.

If you look at a 2 pot or 4 pot caliper set up then the center of the pad is in greater contact with the rotor than the outer edges so the braking performance is not as good as if pressure were being exerted equally accross the whole surface area of the pad. With a 2 or 4 pot caliper set up braking is best in the centre of the pad and decreases towards the outer edges.

 

[Dieselman]

I thought Alx explained it perfectly. by having 12 pistons ( 6 x per pad) you exert a much more even pressure between the pad and the rotor. This means that the friction material on the pad is in much more uniform contact with the rotor resulting in greater resistance making the car stop quicker.

If you look at a 2 pot or 4 pot caliper set up then the center of the pad is in greater contact with the rotor than the outer edges so the braking performance is not as good as if pressure were being exerted equally accross the whole surface area of the pad. With a 2 or 4 pot caliper set up braking is best in the centre of the pad and decreases towards the outer edges.

How do you work out that the pressure isn't being applied evenly, my brakepads wear out uniformly so must have equal pressure all over.

Also, the tyre/road interface is what governs maximum deceleration, so assuming the original brakes were upto the job of locking the wheel, how can different brakes improve stopping ability?

Once again I appreciate how the feel may be improved.

 

[janner]

But the brakes won't lock up immediately from, say 70mph, so the pad to disc friction comes into it as well.
Are the pads the same area as the originals?
If those disks are the same size as well then drilling holes in them reduces the friction material available hence the braking efficiency is reduced. Drilling the disks to improve cooling will only help if the current setup gets them so hot that they no longer work properly but I guess for road use that rarely happens?
Would also be interesting to know the weight compared to standard.

They do look lovely though

 

[Alex]

Dieselman, you've blinded me with science! Seriously though, you bring up good points.

That said, Brabus spend a lot of money on R&D and fit 12-piston brakes to all their supercars. Surely, they must know better?

 

[Alex]

But the brakes won't lock up immediately from, say 70mph, so the pad to disc friction comes into it as well.
Are the pads the same area as the originals?
If those disks are the same size as well then drilling holes in them reduces the friction material available hence the braking efficiency is reduced. Drilling the disks to improve cooling will only help if the current setup gets them so hot that they no longer work properly but I guess for road use that rarely happens?
Would also be interesting to know the weight compared to standard.

They do look lovely though

Pads are not the same. Here's the picture I've made when I also had 6-pot Brabus kit in my possession (now sold to a kind gentleman in Singapore). You can tell that 12-pot calliper has the biggest pad than those of 6 or 4:

 

[DRBC43AMG]

I havn't seen a price for this setup. Is the missus watching this thread and stands ready with a mallet in hand to clobber someone