Turner power steering pulley a different size?

[JubJub]

Hi all,

Received the power pulley kit from turner and the power steering pulley appears to be a bit larger. Is this normal? Will it put any extra stress on the belt?

Thanks for any input guys

[Wishno87]

Please excuse me if im wrong but that is the whole point of a "power pulley" set right? To underdrive the accessories? If they were the same size you would get no gains right?

[bimmerteck]

Yep, if they weren't any bigger they wouldn't really be any benefit. Other than getting rid of the craptastic plastic pulleys on some BMW motors of course.

[Beej '86 325es]

M/S50's used two different types of PS pumps with different sized pulleys. ZF (most years) and LUK (I think just used on the early NV engines).

I had this difficulty when building my motor as well.

EDIT: Sorry, I just re-read the issue. Wishno87 is correct, the larger pulley will underdrive it, and the kit should come with a different belt to compensate.
My issue was mostly pertaining to my difficulties finding the right PS pump mounting bracket. :)

[JubJub]

Thanks for educating me you guys. I didn't realize the larger size is what under drives it. Am I understanding this correctly?

[frankie591]

Yes that is correct. Larger pulley on the power steering means that the crank pulley has to turn further in order to rotate the power steering pump 1 revolution. This means that the ps pump spins more slowly, and robs less power at higher rpms.