Brand: Optimum Balance Products (OBP)
A high-pressure radiator cap helps to ensure against overheating. Raising your coolant pressure will raise the coolant boiling point (1 psi adds approximately 2°F to the boiling point, depending on your coolant mixture).
This high-quality cap from obp Motorsport is rated to 15 psi nominal pressure (holds between 14 and 16 psi). Fits standard full-size SAE "A" size radiator necks (necks measuring 1.26" / 32mm ID and 2.2" / 56mm OD) only. Cap OD measures 59mm (less ears) with a 28mm reach. Sold individually. Two caps are shown in the photo to illustrate the double-seal design.
Before installing a high-pressure cap, have your cooling system inspected and pressure checked to make sure that it can handle the increased pressure.
Note: This double-seal style cap is designed for "open" cooling systems only. If your radiator or header tank vents into an open catch tank, this cap will work. Modern cars with "closed" systems which draw coolant back into the system from an expansion tank will need to use a different type of cap.
