Reduction Pulley Sizes

[MINIAC]

Reduction pulley sizes are always referenced in terms of percentage. The following table looks at pulley size in terms of diameter and lists diameters (half millimeter sizing) which approximate JCW, 15%, 16%, 17% and 19% offerings.

65.5mm = Stock
58.0mm = 11.45%
56.0mm = 14.50%
55.0mm = 16.03%
54.5mm = 16.79%
53.0mm = 19.08% 

It would be interesting to know the actual diameters for different aftermarket pulleys.

[Fisher]

I can write you for Kavs Motorsport one:

58mm - 11.5%
57mm - 13%
56.5mm - 14%
55.5mm - 15%
55mm - 16%
54.5mm - 17%
53.8mm - 18%
53mm - 19%
52.5mm - 20%

[UnXpectedError]

maybe someone could post up the rotational speeds of the supercharger with each pulley size? that way people can tell which pulley they want to run based on the rpm's of the pulley vs the 14,000 rpms efficiency range of the M45 supercharger.

here is the 19% rate at 7k that i found in another post

17,802rpms at 7,000 rpms

[Keano]

Quote: Originally Posted by UnXpectedError (original)

maybe someone could post up the rotational speeds of the supercharger with each pulley size? that way people can tell which pulley they want to run based on the rpm's of the pulley vs the 14,000 rpms efficiency range of the M45 supercharger.

here is the 19% rate at 7k that i found in another post

17,802rpms at 7,000 rpms

That information is available on another mini forum

Rounded to the nearest 100rpms engine speed, the 14k 'limit' for the M45 'charger for different pulley sizes is as follows:

Stock @ ~6800
11.5% @ ~6000
14% @ ~5900
15% @ ~5800
16% @ ~5700
17% @ ~5600
18% @ ~5500
19% @ ~5400

Note that the above are rough and are assuming a stock CP size.