AP Racing Catalogue Issue 4

84 visit www.apracing.com for installation drawings & up to date product range details PROPORTIONING VALVES GENERAL DESCRIPTION These valves have been specially designed for use in competition vehicles where it is desired to reduce the hydraulic line pressure, and therefore braking effort, of the rear brakes to compensate for varying road / track conditions or vehicle handling characteristics. GENERAL INFORMATION ◘ INSTALLATION To obtain the best performance using these valves, the brake balance should be biased towards the rear, so that with the valve piped into the rear line and set in position 7, or the cap screwed right in (clockwise), where virtually no reduction occurs, the balance is as much to the rear as will ever be needed. Placing the control lever in positions either 6 to 1 (or screwing the cap outwards) will progressively reduce the rear line pressure, giving more bias to the front. ◘ WARNING Due to internal adjustments set by AP Racing, do not strip these assemblies. - DO NOT attempt any modification of these valves. - Strictly for competition use only. ◘ NOTE These proportioning valves are suitable for use with any brake fluid that conforms to DOT 3, DOT 4 or DOT 5.1 standards, but best all-round performance will be achieved with either AP Racing R4,R3 or R2 brake fluids. CP3550-13 - 7 POSITION LEVER TYPE This lever type valve provides the driver, or the co-driver with seven distinct settings from which to select the most suitable braking ratio. Basic Installations CP3550-14 SCREW TYPE This screw type offers infinite adjustment within the limits of normal brake operation. With the cap screwed fully in no reduction in output pressure occurs, with the cap screwed fully out output pressure is reduced to approximately 1/3 rd of input pressure. Basic Installations Note: Drawing for guidance only. Download latest issue installation drawing from www.apracing.com Performance Details CP4550-1 - TWIN BORE LEVER TYPE This twin bore lever type, is a 2 in and 2 out valve. This valve enables the user to utilise original fluid pipe runs on Grp ‘N’ or similar applications, where a tandem master cylinder (diagonal split system) is specified. This provides the driver, with seven distinct settings from which to select the most suit- able braking ratio. Basic Installations Performance Details For CP4550-1 & CP3550-13 Lever Type 10 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0 0 20 30 40 50 80 90 100 60 70 POSN 7 POSN 6 POSN 5 POSN 4 POSN 3 POSN 2 POSN 1 TOLERANCE BAND Input Pressure (bar) Output Pressure (bar) Range Of Adjustment VALVES SETTINGS CHART WITH TOLERANCES Output Pressure With 100 bar Input Pressure Posn Nom Min Max 1 38.0 34.5 41.5 2 44.5 41.5 47.5 3 50.0 47.5 52.5 4 55.0 52.5 57.5 5 60.5 57.5 63.5 6 66.5 63.5 69.5 7 73.0 69.5 76.5 > > > > > > > Input Pressure Output Pressure TYPICAL VALVE PERFORMANCE 10 0 0 10 20 30 40 50 60 70 80 90 100 20 30 40 50 60 70 90 100 80 90 BAR ± 6 BAR Range Of Adjustment 39 bar ± 5 bar Tolerance Band Fully Out Position Tolerance Band Fully In Position 26 bar ± 4 bar Typical Valve Performance > > > > > > > > > Input Pressure (bar) Output Pressure (bar) VALVE PERFORMANCE CHART Ø36.0 2 OFF M6 CLEARANCE HOLES C/BORED Ø11.0 TO DEPTH 7.0 CONNECTIONS TAPPED M10 x 1.0 SPOT FACED Ø17.0 30.00 INPUT 37.90 21.50 Ø28.00 40.00 57.50 8.75 21.10 37.50 2.00 OUTPUT FULLY OUT, 95.00 MAX MINIMUM OF 1¾ TURNS KNURLED SURFACE 15.11 33.11 6.50 ANTI VIBRATION CLIP. SUPPLIED AS LOOSE PART 68.68 40.00 57.50 8.75 22.10 69.28 166.75 Ø33.00 14.50 Ø23.15 INPUT OUTPUT Ø31.00 38.90 38.50 POS. 1 POS. 2 POS. 3 POS. 4 POS. 5 POS. 6 POS. 7 105.00 22.50 2 OFF M6 CLEARANCE HOLES C/BORED Ø11.0 TO DEPTH 7.0 CONNECTIONS TAPPED M10x1.0 SPOT FACED Ø17.0 Note: Drawing for guidance only. Download latest issue installation drawing from www.apracing.com Note: Drawing for guidance only. Download latest issue installation drawing from www.apracing.com OUTLETS X 2 INLETS X 2 49.5 7 6 5 4 3 2 1 7.0 82.0 72.0 7.0 5.0 34.0 MAX 20.7 18.0 137.0 MAX NOTE: 7 POSITIONS ON CAM/LEVER FOR ADJUSTMENT. 22.5 43.5 2 MOUNTING HOLES Ø6.5, CBORE Ø12.0 INLETS X 2 18.0 34.5 14.5 9.5 10.5 30.5 16.95 OUTLETS X 2 NOTE: ALL HYDRAULIC THREADS ARE M10 x 1.0