Sprintex BRZ/FR-S Pulley Selection Chart
We get this question almost daily! What pulley to run on 91 octane? What about intercooled? Can the 335 system be used on a road course? The worksheet below summarizes our experience running every version of the kit. The limitations of the system are the smaller laminova intercooler core, and the heat generated through compression. Combined with the 12.5:1 CR of the BRZ/FR-S FA20 motor, the chart below offers the best balance of knock resistance to performance gains. If your car does both double duty with e85 and pump gas, pulley changes can be made in about 5 minutes with common tools. Alternatively a map can be set up using EcuTek RaceROM to pull out more timing for pump gas operation. This allows you to run e85 at the track while still remaining relatively safe on pump gas during regular operation. For built motors, you will require a smaller pulley to achieve the same torque if dropping compression. So a 75 mm pulley on the 335 kit is nothing drastic when running 9.5:1 CR. With any of these kits, we don’t recommend dropping the compression much below 10.5:1. With the direct/port injection combination of the Toyota D4-S system and dual VVT, you can get away with a good deal of static compression and still run fairly high boost levels.