Quote:
Originally Posted by ERA 626
All this knob does is restrict the amount of fluid passing through it ie proportioning valve (brake bias)
|
This is not Correct...
The Proportioning Valve is a pass Thru body with a ball and spring inside the housing. As the knob is screwed all the way in...fully clockwise....the spring and ball is compressed in the body of the Proportioning Valve. Therefore, as you put your foot on the brake pedal and increase pressure in the brake line .... the pressure goes thru the proportion valve and to the caliper at the same pressure that came into the proportion valve.
If you back out the proportion valve to the minimum setting... as you apply pressure to the brakes the input pressure is the same as before, but, with the spring and ball backed out to the minimum setting, the pressure will go to the caliper and then the spring and ball will forced up into the proportion valve body and this fluctuation will reduce the pressure to the caliper.
The ration of input to output is from 1:1 to 1:3 so that the pressure applied to the caliper is reduced as the pressure goes up because the spring and ball in the proportion valve flex as you apply more pressure.
You can never get more pressure out of a Proportional Valve, however, a Proportion Valve and a Balance Bar can fine tune a brake system to assist in making the car tune-in better as needed on various tracks.
We've been running both items for years and use the Balance Bar as the course adjustment and the Proportion Valve as a Fine tune adjustment.
