People on Youtube claim some herb they found in a cave made their dick 10" long or that some politician is a genius. They're all doing it for the views.I must admit..this is getting a bit confusing. I surly appreciate the advise but ..for the last few day i have been reading many,many postings from guys that have done the blazer dual piston swap with a better pad and some also with the 12" caprice dual booster ..many utube vids all claiming its "night and day". The fact that the pad area and piston area is greater it seems logical there would be more contact area so by default better braking...add more vac assist to that to create clamping pressures. This is a very researched upgrade. Can find many utube vids on the swap...i can't believe they are all mistaken. Gbody.com covers this is depth too.
Engineers don't care about Youtube. They do the math and check the results.
Here's a spot with the actual formulas:
Forces and torque activated with disk brakes.
Here's a handy brake rotor torque calculator that does the math for you, and also has some extra stuff that'll tell you how much brake torque you need to accompish a desired deceleration rate
Plug in your numbers, then start fiddling with them. You'll see quickly that rotor diameter has very little effect when you're talking about a quarter inch increase in diameter (remember, you're going to the center of the pad, not the edge for the calculation). Going from a 10.75" rotor to 11" is not even a 3% change in that variable. But changing out a pad with a 0.4 coefficient with on that has a 0.6? That's a 50% increase in that variable, and they're multiplied together. It's all about the pad.
All these folks saying it's night and day are crediting the Blazer swap with the effect they received from simply servicing their neglected brakes. New pads, new fluid, replacement lines. A lot of the time they also got new wheels and tires. Their stock setup probably had play in the bearings which can make the pedal feel mushy. The blazer spindle is a newer style cartridge bearing that doesn't get loose, it just starts making noise until it falls off. None of them ever have any data, just how it "feels".
I ran several full seasons using the old Wilwood kit that used a 10.75" (stock diameter, fit inside a 15" wheel) rotor. I thought it was absolutely terrible until I got a set of stupidly high friction race pads. Suddenly my brakes worked (after they warmed up). Now, a rotor that small couldn't shed the heat and I ended up in a situation where I was completely replacing the rotors and pads and bearings after every event, but during the event, they worked fine. 140-60 for Turn 1 at Putnam no problem, lap after lap, for a whole weekend.
I switched to the 12.88" rotor kit with the six piston calipers not to get more stop but to get more life out of the parts. I ran a whole season on one set of rotors and just two sets of pads with the bigger kit, but I cannot claim the car brakes in a shorter distance. That's actual data. Real information.
The puny stock brakes are actually sized appropriately for the weight of the car and the stopping distance targeted by GM. What they lack is durability, especially in extreme use cases, but that's the same story with all stock brakes up until the early 2000s when the automotive press suddenly started caring about performance and OEMs realized blangin' brakes could drive sales.
Properly serviced and with good pads and tires and adequate line pressure? They will work fine. Anything bigger is either bling, or you're doing something dumb like me.
And here's my final point:
THERE IS NOTHING WRONG WITH BLANGIN' HUGE BRAKES. If you have the cheddar, do it. They look awesome. Just be honest with yourself about why you're doing it - because it looks super cool.