ARP CA625+ Extreme Duty Head Stud Kit

Audi 2.5L EA855 TT-RS/RS3 DAZA ARP CA625+ Extreme Duty Head Stud Kit

This kit was designed for drag or street racers running high-boost engines that require more clamping force and tensile strength than the ARP2000 and L19 Stud Kits can offer. If you are looking for the best option, you’ve found it—these studs are 20% stronger than ARP2000 and provide a 62% increase in tensile strength over OEM torque-to-yield (TTY) bolts!

Due to frequent “head lifting” issues on Audi engines running more than 50 PSI, a stronger stud was custom-made to meet the demands of today’s top engine builders and racers. The Custom Age 625+ newly formulated super-alloy demonstrates superior fatigue cycle life, tensile strength, and toughness—with complete resistance to atmospheric corrosion and oxidation. ARP is the first to develop manufacturing and testing processes for fasteners with Custom Age 625+.

No modification to your Audi RS3 or TT-RS cylinder head or block is required, as these are a direct drop-in replacement for the OEM head studs.

Tensile Strength: 260,000-280,000 PSI

Note: The nuts and washers in this kit still utilize premium-grade 8740 alloy, as only the stud is subjected to increased pressure. Each kit contains complete CA625+ head studs, nuts, and ARP