There are quite a few guys that have turned down their stock SC pulley to 70mm (mainly to work more safely with stacked pulleys) but my question is for those guys that want to keep running the 65mm pulley, has anyone ever turned down a 178 crank pulley to say 165? Has this question arised and already been shot down before?

 

I don't follow the reasoning behind machining the CP down, as that would decrease boost.


EDIT - Okay, I see what you're saying now. Machine down the CP so that the 65 can be run and not overboost the engine. Sounds like a lot of work since the CP is a PITA to swap. I haven't heard of anyone doing this, Keep in mind, they'd be throwing money away by destroying their performance CP, but you never know.

 

Correct. Thats actually my point. It seems as tho when stacked 65/178 ur gonna get 22+ psi at a minimum. But for those that wanna stick with a 65mm (rather than turning down oem to 70mm), they could turn down the CP to be around 18-20 psi.

 

Right, but a 178 CP is expensive and hard to swap (labor intensive and risky). I don't think you'll find anyone that went that route as opposed to machining the stock pulley, but I suppose it's feasable.