Disc brake conversion (70 Dart)

66fs said
However it is an acceptable way to compare brake systems at a simplified theoretical level. 72bluNblu calculations are more accurate than yours. Your swept diameters are off and you neglect the friction on the second brake pad on a floating caliper in your calculations.

It's the same calculator posted on other sites. It doesn't work, it doesn't address plateau, the friction coefficient is a middle of the road number, and it doesn't calculate based off each individual caliper piston or vehicle weight or address static axle load distribution and assumes clamping load is always equal on all friction surfaces. There is also a factor that can be added for heat and kinetic energy, inertia changes when different size wheels are used. A correct calculator would have my numbers lower, but the old +73 you are always assuming in a perfect working model. They won't be. And your braking force on your +73 (if you want to accept those numbers as golden) can only be generated if the wheel does not lock up. Your numbers have it locking up long before reaching your maximum clamping force. So that alone reduces the braking force because it's sliding the tire. Cold drum brakes can stop better than disc brakes that are cold. And if you are using a .45 for friction, those pads will have to have a little heat to work properly.

40 year old technology? Caliper style disc brakes where invented in the 1890's. Our modern hydraulic disc set ups all have roots to early 1950's designs. It's just a piston with fluid pushing it, I'm not getting where you think nothing has improved over the years or are you expecting some new way of clamping a brake pad?. Your floating calipers are prone to stick and are way more common in producing uneven pad wear, your single piston footprint produces pad flex and doesn't grip the rotor evenly, so throw out your .5 friction coefficient of you Hawk pads. It's also the reason why Neon's got recalled for the brake pads coming off the backer plates. They flexed too much.

I'm sure the OP just wants to get a little more updated braking than drums and should be fine rebuilding what he has. He really doesn't need to know much more.