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I was looking in Classic Chevy's Tech Book that to reduce the brake pedal travel to hard pedal start drill a new 3/8 hole 1 " lower than the orginal hole to reduce the pedal ratio from 5 to 1 to new 3/1 ratio. Not my trick but I will use it on mine. :bowtier:
 

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There are some other things to think about before doing this.

First is that the pushrod needs to push on the booster or master cylinder at 90 degrees to the mounting face. So if you relocate the spot where it attaches to the pedal arm, you create an angle that's not 90 degrees. Being off angle means the pushrod may not even assemble into a master cylinder, its action may bind up, or you will wear the booster or m/c prematurely with a side load. And some of these boosters just have a big plastic shaft that may wear pretty fast.

The above deal is why a lot of these booster mounts are at an angle. They are meant to have the pivot point moved, and the mounting angle compensates.

The second thing is that when you change the leverage to shorten the stroke, you lose force at the booster or master cylinder relative to the force you apply at the pedal with your foot. The stock pedal ratio is actually 6:1, and when you re-drill the pivot 1" down, the ratio is 4:1. What you get is 4/6 of the stroke or two thirds what it was. But the force applied at the master cylinder or booster is also two thirds of what it once was. Described another way, that means you need 50% more force at the pedal to get the same braking you once had.

Another way to accomplish these things is to change the bore size in the master cylinder. If you had a 1" bore master cylinder, and replaced it with a 1-1/8" bore master cylinder, your stroke would be reduced by the ratio of the bore areas. This means that going with the 1-1/8" m/c, you'd have 79% of the stroke, but also 79% of the braking force you once had, and that you'd have to push the pedal 27% harder than you used to.

But you can find a master cylinder with either bore size (or others) that bolts up exactly the same way, so pushrod angles and other geometry is not affected at all.

Bottom line on this, less stroke = more pedal force to stop the car.
 

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I would have guessed it's the wheel cylinder bore area (for all 4) divided by the master cylinder bore area.

But I plugged in some logical numbers, guessing at the wheel cylinder bores and knowing that the m/c is 1", and I didn't come up with 4.55, the numbers are smaller. So my speculation is incorrect, or I'm guessing wrong on the wheel cylinders.

The way I measure the pedal ratio, I come up with exactly 6:1. I measure the distance for where your foot is at the middle of the pedal pad. A higher number might mean it's measured from the bottom of it, and a lower number would be from the top.

It's kind of like the front spring lengths that GM shows, they certainly aren't the overall length of the spring. Somebody there had a different idea of the reference point.

Another deal on "where is the reference point" is the recent discussion on how far forward you should mount an LSx engine relative to a traditional engine.

Engineers defy other engineer's logic on point of reference sometimes.
 

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The way I measure the pedal ratio, I come up with exactly 6:1. I measure the distance for where your foot is at the middle of the pedal pad. A higher number might mean it's measured from the bottom of it, and a lower number would be from the top.
That's what I've always used too, 6:1. I measured to the center of the pedal. My guess is they figured from the bottom of the pedal because you could theoretically put your toe there to push the brake pedal. :sign0020:
 
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