Moparts Tech Archive
Disc Brake Tricks?
Is there any way to get rid of that little bit of drag that stock front disc brakes have? This is for a race only application. thx matt s---------------------------------------
do you have to run the correct year of brake caliper in your class or something? there are disc brake calipers that don't drag. the ones the Brembo makes (stock on viper) do not drag since they have self-retractors on them.
here are viper calipers mounted onto late B body rotors.
All modern calipers have a square cut seal in a trapezoidal groove. The out of parrallel side of the groove is on the unpressurized side of the seal. Brake pressure causes the seal to deform against the groove. Once the brakes are released the seal returns to its original shape and retracts the piston. The outboard pad on calipers without outboard pistons may get moved back by runoutof the rotor, but the inboard pad if attached to the caliper piston is slightly retracted. Calipers with pistons on both sides will retract both pads. The Chrysler designed calipers have this feature, I am not sure about the four piston Kelsey Hayes.
Use a coil spring between the two pads over top of the pin. Play with different lengths until you have enough pressure to just take the drag off the rotors. You will notice a little bit of pedal softness like when drum brakes are out of adjustment. Nothing bad or to be concerned about. I used this for years on a street car with no problems. The springs will not effect any stopping power either. Cheap, Easy and FREE horsepower.