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Discussion Starter · #1 ·
Hello,

It would seem if you could get a little more breaking power to the rear, you could improve stoping distance. Has anyone tried this? IE modified the Master cylinder, or bought an after market one? Or is my Physics theory on this wrong?

Scott Milella
 

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Discussion Starter · #2 ·
<b>RE: Makes sense</b>

Don't know of anyone trying it, but once the front wheels are locked they can't provide anymore friction, so until the rear wheels lock friction can be increased.

I would think the modification would have to be made to the proportioning valve on the firewall possibly?
 

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Discussion Starter · #3 ·
RE: Brake question

The back brakes on most cars only provide 25-33% of the stopping power. So increasing the braking force on the back wheels ins't as effective as increasing the braking force on the front wheels. You can use an adjustable proportioning valve to help balance this, especially if you've made upgrades to the system. You get maximun braking force right before locking obviously, so if you could get all 4 wheels to lock at the same time, it would be ideal. However in the real world, your weight transfer will vary from stop to stop so the loading forces can't be known for sure. Compromises must be made. Man, that sucks.
 

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NO: the correct thing is the other way around

When braking the weight goes to the front so the brakes that need the most pressure are the front ones, at high speeds it is very difficult to lock them, and when locked will need to play with it for control. So the proportional valve is used to give more braking power to the front. Also used with big calipers because they have more area in the hydraulics so they loose pressure.


Danilo
 

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RE: Makes sense

Here is my setup: 88 ToyotaV6 4x4 calipers on 1984 300zx rotors with Performance Friction Carbon pads up front, Rear 280ZX rotors and calipers in the rear with Metal master pads, a 280ZX Master Cylinder, braded brake lines all the way around, and a wilwood proportioning valve and 4 inch cooling ducts. The Wilwood Proportioning valve sets bias front to rear. The idea is to set the bias so all four wheels lock at the same time. It is an excellent set up and the same setup has been tested on other cars and shown that 10 repeated stops from 80 averaged at less than 130Ft, 80mph, not 60mph. Big performance gain.
 
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