SC and pulleys ...

[Belgiumbarry]

i bought a SC kit with a Raptor V that uses the water pump/AC belt ... but that one is driven by the small crankshaft pulley . To have it spin at 18.000 rpm ( max ) we need a 1:3 ratio. The crankshaft pulley is 124 mm , so we need a charger pulley of 40 mm ! way to small , for the belt and slippage.

I tested a 45 mm pulley and must say no slippage so far …. i wanted bigger , at least 55 mm, so i looked to make the crankshaft pulley bigger , which would also spin the waterpump/fan a bit quicker …. no harm i suppose with the extra heat generated with a SC....

We made a aluminium ring , cut it in 2 , mounted it on the pulley with a pin (for torque) , and welded it . Welding crimp gave it a firm hold around the oem profile. Afterwords i machined the belt profile . Measuring clearence with water pump pulley and belt tensioner i calculated it was possible to have now max 165 mm , perfect to have 1:3 with 55 mm above.
I also just stay within the max belt speed as recommended by manufacturer.

Test will be for later this week , i bought a belt which seems to long .

SAM_2551.jpg

[TxGR8White]

Make sure you have that assembly balanced before you run it.

[Belgiumbarry]

i tought that wouldn't be necessary .... ? the weight of the aluminium ring is almost nothing compared to the damper/pulley. And all is machined on a lathe.