Hi,
I have seen stock crankshaft pulley measures 154.4 mm.



I am pretty sure the 154.4mm are wrong for the stock size crankshaft pulley.

Me and my buddy have measured 3 different SLK32 / C32 AMG stock size crankshaft pulleys (same as SRT6) in different ways with different tools.

150.5 mm! Not more than 151mm for sure.

We have also measured supercharger pulleys for a comparison, because we thought we are wrong. But they are 74.2 mm stock size and 65mm IBF pulley as advertised.

This could explain why a 185mm crankshaft outperforms a 62 mm supercharger pulley.

185/74.2 = 2.49326145553
150.5/62 = 2.42741935484

It`s not the belt slip it`s the bigger ratio :-)

Steven
Berlin Germany

 

Same for the 178 mm crank vs 65mm supercharger pulley.

178/ 74.2 = 2.39892183288
150.5/65 = 2.31538461538

178mm wins :-)

 

Mine is 154.4!

 

[QUOTE=JEFASOLD;912061]Mine is 154.4![/QUOTE

Ok. So maybe different part numbers? I know there is a old and a newer model pulley.
As stated. I got the numbers for the sc pulleys. same as on this list above. Also we did the math with circumference an "pi".
Everything measured without belt.