The Devil

Re: Well I be getting my s4 rotors and porsche 4 pots couple weeks... Coupe Quattro conversion

Taner Halicioglu

:-P~~~ !!!!!!!!!

LI-S4

Two pistons...but with four pads and full floating calipers...

bitrbo

yup.....:P

jyoteen

I'll trade ya!

frank

a fixed caliper, like a 4-pot brembo
is usually much stiffer and more expensive
than a floating or sliding caliper

bitrbo

Sure.... we'll just trade cars.... right after you're done with your RS4 conversion....:P

Ted K

Okay, my turn for a lesson. Could you explain this to me??

LI-S4

Traditionally the caliper is bolted to the carrier and is stationery in relation to the rotor.

Braking occurs when the pedal is pressed which forces the pistons to squeeze the pads against the rotor. Important point...the caliper does not move only the piston. Obviously with multiple pistons there is greater effort against the rotor, but still the caliper stays motionless. Many cars, maybe even our rears, have but one piston...

As TechGuy explained the caliper on the S4 floats. It is bolted to the carrier but is allowed to move as the piston moves so effort is applied evenly on both sides of the rotor.

That said, you can't beat the even application of effort from a four pot caliper.

What I don't understand is why four pads?

frank

in a simple way of thinking

means that the two pistons, push against 2 pads on that side
which in turn push against that face of the rotor

this in turn causes the OTHER side of the caliper
to move or "slide" (hence floating or sliding)

and causes the OTHER two pads to exert pressure against the other rotor face as well

this is an over-simplified description,
but gives you a rough concept of a FIXED, 4-piston caliper (2 pistons per side)

vs a FLOATING 2 piston caliper