I am getting a crank pulley install and want to get peoples opinions out here.

I am running a 15% supercharger pulley and I am thinking of going to the 2%. Is this a good idea for the durability of the engine?

Thanks in advance to the advice here.

 

Well, I can only speak for the 0% since that's what I have installed, but I'd probably opt out of doing the 2% and just install the 0% or 05/06 crank pulley. As far as durability, I suppose everyone is gonna have a different opinion and as far as what I've read in the past about this same issue, most of the knowledgable folk recommend going with the 05/06 pulley; it is not only lighter than previous year crank pulleys, but still has the harmonic damper. I haven't had any issue with my 0% and I've driven over 10k miles thus far, but I figure I'd provide you with some incite that I've come across when I researched this same issue in the past. The lighter pulley is certainly a welcome change, though, since it allows the engine to rev more freely.

GotMINI

 

I've been running the M7 2% with the M7 16% for a while now, and have had no issues and I get into a lot of street fights around here. There are guys on here that are running a light weight crank pulley that I know drive harder than me, they have had no issues either.

 

I would get an 05/06 crank pulley, I have a 2% on my car (and a 4% in my toolbox) with 15% pulley. Since install, the car pulls better but I have a little rattling sound coming from the belt tensionner a low revs (900 to 1500) that I really dont like. No big deal there as pass 1500, the noise is gone and the car runs perfectly. Same thing on a friend's car, got rid of the noise by installing a NEW belt tensionner... wich he really needed anyway... If I ever have the chance to find an 05/06 crank pulley, I will swap it right away.

 

I dont have any valid input, but if you are interested I do have a brand new M7 2% crank pulley to sell as I decided to go a different route with the car. Just thought I would let ya know in case you are interested in the 2%.

 

Running the m7 2% crank with m7 16% sc pulley on my '05mcs. No problems to report after 8k miles. No vibration to report either.

 

I just got back from the Detriot Autoshow and I got in touch with a marketing/technical person and just bluntly asked about this mod and he said go for it. He had a bunch of mods to his 2003 MCS and has a lightweight 0% pulley from Alta. He said that our bottom ends are overengineered as all BMW are. I am going with the 2% crank pulley. I might as well get more since I am having it done by Way at Waymotorsports. He is coming over to my house and doing the install with my help.

 

For what you get out of it, I wouldn't take off the stock.

Spend some time searching as I did and you might change your mind.

Longboard

 

Longboard,
I did some research, but can you direct me to those sources that lead you to your decision? I have read the subaru boards about Perrin/Alta Crank pulleys and I have looked at the MINI owner's research for lightweight pulleys. It is interesting how MINI went to a lighter crank with less isolating rubber in the 05 and 06 model years.

Please let me know your sources as I am in the process of planning my install with Way.

Thanks,
Carl

 

Don't let others scare you. The +2% Crank and 15% SC pulley are safe mods.
I have not heard of anyone having a issue with them.