Selection Guide
| Grade | Performance Level | Suitable for | Base Material | Alloy added | Heat Treat | Vane | Friction surface machining |
| HP | High performance | Street driving and weekend racing | Gray iron | Yes | No | Straight | Drilled + Slotted; Slotted only |
| UP | Ultra performance | Track racing | Gray iron | Yes | Yes | Curved | Slotted only |
| XP | Extreme performance | Extreme club racing (SCCA) | Compacted Graphite Iron (CGI) | Yes | Yes | Varies (per rule) | Plain fine cross cut only per SCCA rule-No modification |
| High Performance | Ultra Performance | Extreme Performance |
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