[Babes]

I spent about 2 months trying to research this exact thing. Already had the 3% lightweight crank pulley from GT Tuning but after hearing a few negative stories held off on fitting it. From what I have read it seems incorrect fitment is the major reason for having dramas.

I asked my BMW service dude what the long term effects would be and he said in 2/300,000 kms may need new bearings. Have had mine fitted for about 3000kms now and it has completely transformed the car.

No doubt there will be a lot of folk saying dont do it, as there is no real long term data on what the effects are. Roland from GTT has 20,000+ miles on his crank pulley now without problem and his seems to be the longest tested one to date.

Some lightweight crank pulleys seem to be worse than others but I have only read good things about the GTT one. If you look on NAM there is a bit more info on them.