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Hey guys, I'm a newb to me/be, but have been a car enthusiast for over 20 yrs now. Just purchased an '04 E55 and the modding bug is biting hard. So here's my question. Reading K1's site, they sell an ASP crank pulley which underdrives the accessories to free up HP, while others like LET sell crank pulleys to overdrive the s/c. Have the results been similar comparing an ASP to a 172mm LET? Does any vendor offer a crank pulley that does both, underdrive the accessories while overdriving the s/c?