I figured I would jump in and give some of my experience with brake systems..especially being around quality control for the automotive industry for many brands..here's my wisdom to you all...
- Calipers that have more pistons usually take the same if not a little more fluid though the braking system is designed to compensate for this.
- Why you ask? Because one big piston is compared to two half sized pistons, or four even smaller pistons. If the piston size stayed the same, it would be pointless to have that massive brake power in a vehicle that does not need it and you would have one massive caliper going halfway around your caliper. Besides that, the purpose of more pistons is not necessarily for more power but to allow the pad to "float" on the rotor to lessen the feel of defects on the rotors (warping).
- One way you throw off braking power is if you install a bigger brake setup on one end of the car and not the other. One end of the car will have a bigger advantage over the other. This is more evident in slip conditions in snow, rain, etc.
- Over tightening your lug nuts can "contribute" to your rotors warping. Remember a rotor is one big piece of metal that conducts heat and metals expand under heat, especially the heat brakes create. Summer months are even worse when the ambient temperature is up there aside from humidity which causes heat to linger.
- More expensive rotors do not always mean better. There's a fine line between quality and looks and unfortunately some people base everything on looks or because its plated or powder coated or slotted or cross drilled, etc. The best rotors by far I have ever had were Brembo blanks right from Italy. They were heavier due to the more dense iron allowing it to handle more heat. The way they poured molten iron into mold was uniform. So you don't get "hot spots" like in stock rotors because parts of the rotor were more dense than others. The rotor also expands with heat more evenly preventing the possibility of warping due to high and low spots. But in a world where business dominates, brake jobs for dealerships is their "bread and butter" so to create a "perfect" setup only exists where you pay top dollar for it.
- Cross drilled rotors are only good if they are molded with the holes. Drilling a rotor after the fact introduces stress cracks that you will only notice after time which will either crack, shatter or warp in strange ways. If this hasn't happened to you, you're considered lucky or you bought something of high quality.
- Washing your car or going through a drive-through car wash can warp your rotors if they are hot enough. Heating something to a high temp then cooling it down too fast is not good for iron unless you are forging it.
- If you wash your car and leave it parked the same way without driving it a few meters will introduce pitting into the rotors. Remember that iron is very susceptible to rusting and pads contain metals that will fuse with the rotor. With the introduction of water into the mix, the two metals will fuse and once you move, they create pitting that under braking will make you feel as if your rotors are warped. They're not, you just have surface defects that aren't smooth which is what you're likely feeling. This pitting will go away after some normal braking but if the pitting is bad enough, this will become a "hot spot" and the rotors will start to expand unevenly causing warpage.
There's probably more info I can give you guys, I just can't think of it at the moment.
Most brake problems are caused to the issues I explained above but some are also due to the quality of parts. Fact is, most stock brake setups aren't designed to handle north american driving unless you have the Akebono's which are on the 2nd gen FX50S and other Infinitis like the G and M. Fun fact, those Akebono's brakes were first designed for the European market due to their "high-speed driving" demands. So what does that tell you?
The best setup is to have bigger rotors and more pitons on a caliper that is a floating design like the Akebono and other aftermarket designs as such.
Anyways, that's my .02, these are of course opinions based on real-world facts that I myself have experienced personally and working in an automotive quality control and testing facility.
