6piston brake on 135i only?

[PrematureApex]

Originally Posted by crzy4135i

They need to do something.. There are many other cars that have 6 piston brakes fitted from the factory.

Why? If they are achieving the performance they want with large single pot sliders, no reason for them to move on.

Counting pistons is a marketing issue rather than a performance improvement.

Not like I don't like the added pedal feel of an opposable caliper, but I never thought any or their sliders offered bad feel.

[350 to 1]

Originally Posted by Shifter Kart

As been stated the real advantage is in having fixed calipers and not floating calipers. This can be achieved without 6 pistons and has been done for a long time with 4. Besides for the "cool" factor, the only advantage to 6 pots is more even distribution of the brake force to the pad leading to more even pad wear.

+1

The direction seems to be going to more pistons. I'm not sure how strong the correlation is between modulation and the greater the number of pistons after 4. Rotora (and I’m sure there are others) makes a 12 piston caliper. I have 4 piston Brembos on my Z and find them to have excellent modulation.

[PrematureApex]

Originally Posted by 350 to 1

+1

The direction seems to be going to more pistons. I'm not sure how strong the correlation is between modulation and the greater the number of pistons after 4. Rotora (and I’m sure there are others) makes a 12 piston caliper. I have 4 piston Brembos on my Z and find them to have excellent modulation.

Not the number of pistons per say. But as you increase the number of pistons, you decrease their diameters, allowing additional material for the surrounding caliper frame as well as a more efficient geometry.

In short, the smaller the pistons, the more practically you can stiffen the caliper frame itself.

[larryn]

It also allows for more braking surface, spreading the friction over a larger contact area for the same stop, which can decrease heat soak. Of course, if you ride the brakes, you're going to cook them sooner as well.

Brake fluid will be my first mod, after seeing if my track wheels fit. :smile:

[350 to 1]

All good stuff! At some point I guess an economical balance is reached for a performance oriented street car, where you just aren't getting a worthwhile improvement in performance for the cost.