I want the dual pistons and their benefits, but not 12" rotors (look at the WBS Stage 3 set for what I want). Larger rotors means more mass for the engine to turn, resulting in slower acceleration.

True, but if we were so worried about that, then we should be looking at lighter flywheels, torque converter, etc. Those are rotating faster then rotors... and the energy required to rotate something is proportional to the rotation speed squared. With a gear ratio in first of about 3:1 (not taking converter slip into account so the crank is spinning even faster than 3 times the wheels), your components spinning at engine speed have way higher of an effect (would take 9 times more energy to spin the same mass). My point? Why don't we look into lighter weight engine-speed components?
I'm just defending my desire for better brakes

Well, I do see your point. Dual piston brakes may be better than single piston 12" brakes. I would actually prefer both. I just love being able to stop when I want. That's more important to me that acceleration. Going from light to light was horrific since day 1. A '72 Mustang I drove had better brakes.

Zuulmusic: You will need brake pads for a 04+ GP in order for them to work. Not sure which year for the Monte.
Strongly recommend ceramic pads as I have a LOT less brake dust now. You can get these at any autozone.

EDIT: I see you alread know the benefits of ceramic pads. Nevermind.

So tastybake, did you notice a BIG difference when you upgraded (or should I say upsized)?

The components in the engine are already moving once started. It helps revs to lighten engine components, but since they're moving already, it's not as big a deal to get them moving faster.

Think of moving a round boulder. Getting it moving is the hard part. Once it's rolling, it's not as difficult to increase or maintain speed.

Tires and rotors have to initiate movement every time a car accelerates. It's the reason big rims aren't used on drag cars. Adding an extra inch to the rotor is adding a few pounds per wheel, rotors aren't light. I'd rather have them go on a diet instead, which is why I upgraded to 16" Torque Stars instead of some 17" or 18" aftermarkets. I'm focusing on speed.

Anyway, if you want big brakes, go for it. These are just limitations I place on my car (it's not an autocross). However, if you're going through the expense and trouble, why not just go with Fbody fodder and get the best? I may end up going that route if I can't do them on a stock rotor.

I replaced my rotors with stock a couple months back and I really wish I had upgraded, braking still blows

I hope I'm on the right page here......

If you are wanting to upgrade to 12" brakes with the Monte/Impala Brackets, you are still using the original GP calipers, which use the original GP pads.... If you change calipers, you will most likely need to change the part number for the pads.

Or did I miss something?

crimpton,

You got it...

You'll need to match the pads to the calipers. Not the brackets.

As for the 12" or 11" rotor and speed. Yes the 11" will be a bit faster then the 12" but the gains will be minimal unless your looking for every 1/100th of a second you can get.

the 12" rotor is still close enough to center of rotation to be negligable when compared to a 16" rim and bigger.

Some one asked if the 12" would work on a 15" rim I'd have to say no. Reasoning would be the 12" does not fit the 16" cross lace wheels so I'd say no fit on any 15" wheel.

Yeah. 12" is really only an additional half inch radius.

I chugged some moment of inertia and kinetic energy equations with rotors and tq converter/flywheel mass and dimensions and the rotors are still tiny compared to them, as far as weight reduction benefits.

Parts already moving really doesn't make it much easier to accelerate. Torque converter is always going to be slipping/rotating faster than the wheels (when unlocked) anyway, so its not like it already spinning is giving it an advantage over the wheels being still initially.
Energy required to accelerate a given object from say 0-2000rpms is the same as it would take to accelerate the same object from 2000-4000rpms.

Herc, I just realized my mistake this morning. Thanks for pointing that out.

Just do what you want. Like I said, I might be following you shortly anyway.