[david in germany]

Originally Posted by Seb335D

Indeed everybody knows than one piston is way better than six !!!

It is about surface area, larger surface area causes more friction. Friction = resistance= stopping ability.
This install has effectively reduced your rotor to pad contact area which reduced the stopping ability of the car, add drilled and slotted rotors and you have reduced it even more. I think the math has been done before and proved a loss of about 8-10% braking ability over the stock brakes.

Piston number doesn’t mean anything if it doesn’t make up for the loss of friction area.

I do have these brakes on my 118i and they were a HUGE upgrade over my 118i’s original brakes but for a 335i/335d... bad choice if you wanted an upgrade for function. If it was for looks only, .

[Seb335D]

Originally Posted by david in germany

It is about surface area, larger surface area causes more friction. Friction = resistance= stopping ability.
This install has effectively reduced your rotor to pad contact area which reduced the stopping ability of the car, add drilled and slotted rotors and you have reduced it even more. I think the math has been done before and proved a loss of about 8-10% braking ability over the stock brakes.

Piston number doesn’t mean anything if it doesn’t make up for the loss of friction area.

I do have these brakes on my 118i and they were a HUGE upgrade over my 118i’s original brakes but for a 335i/335d... bad choice if you wanted an upgrade for function. If it was for looks only, .

You mean friction ?

335D pad



135i pad



Do you know how to calculate a surface ?

Let's explain how a smaller pad can produce more friction than a bigger

[david in germany]

I stated that the math had been done before but did not say that I did it. I mentioned a couple of issues with the setup but not all. Read some of the threads on this very topic here on this forum. BMW does not recommend what you did for a reason. Smaller rotors etc. as I mentioned, for many cars this is an excellent upgrade but for the 335i/d it is not.

By the way, was this your car or the car from a customer?

[Seb335D]

Originally Posted by david in germany

I stated that the math had been done before but did not say that I did it. I mentioned a couple of issues with the setup but not all. Read some of the threads on this very topic here on this forum. BMW does not recommend what you did for a reason. Smaller rotors etc. as I mentioned, for many cars this is an excellent upgrade but for the 335i/d it is not.

By the way, was this your car or the car from a customer?

This is one of my personal cars and I'm used to go on track with this car and what you call a downgrade perform way better than stock brakes.
As you mentioned before it's all about friction, the 135i pad are almost twice the size of 335d pad. The 335d stock have only one piston who push only the inner pad when the 135i have 6 pistons which applies a distributed force on the whole pad on both sides.

[ki_soarer]

Originally Posted by Seb335D

This is one of my personal cars and I'm used to go on track with this car and what you call a downgrade perform way better than stock brakes.
As you mentioned before it's all about friction, the 135i pad are almost twice the size of 335d pad. The 335d stock have only one piston who push only the inner pad when the 135i have 6 pistons which applies a distributed force on the whole pad on both sides.

Not sure why people care what other chose to do with their cars. If you like it and notice an improvement, that’s all that matters.

Now please give me more details on your exhaust set up because it is beautiful!