RMS 8 Rib 7.5 Inch Drive Ring for Modular Crank Pulley
The RMS Modular Crank pulley is a 2 piece assembly consisting of a Crank Hub and a Blower Drive Ring. The 7.5 inch drive ring is for high boosted engines from 13 psi to 22 psi.
This pulley requires an RMS Crank Hub. If you purchased an RMS modular crank pulley assembly in the past, you already have the Crank Hub. Call RMS Tech Support with any questions.
E46 M3 - 1995-2000 S54
E36 M3 Euro
Z3 M Series Euro
The 8 rib 7.5 " pulley is recommended for boost levels above 14 psi and not more than 22 psi.
Re: S50 B32/B30, S54, S52 Engines. Motor-Sport applications that require high boost levels in an endurance condition must use RMS Pinch Rollers with RMS Slide Tensioner setups.
Estimated boost 2 7000 rpm , s52 engine 3.2 litter - Using the V2 Supercharger with 3.6:1 internal step-up ratio
8 rib 7.5 inch crank with 3.8 supercharger pulley = 15.0 psi @ 7000 rpm - 1.97:1 Step-up Ratio = Impeller speed 49,740 rpm
8 rib 7.5 inch crank with 3.7 supercharger pulley = 16.5 psi @ 7000 rpm - 2.02:1 Step-up Ratio = Impeller speed 51,080 rpm
8 rib 7.5 inch crank with 3.6 supercharger pulley = 18.0 psi @ 7000 rpm - 2.08:1 Step-up Ratio = Impeller speed 52,500 rpm
8 rib 7.5 inch crank with 3.45 supercharger pulley = 20.0 psi @ 7000 rpm - 2.17:1 Step-up Ratio = Impeller speed 54,780 rpm
These numbers will vary depending on elevation and or engine modifications.
Please use this form to ask us questions about a product.