Originally Posted by M&M
The answer, my friend, is to raise the rev-limiter 300rpm. You enjoy the torque multiplication in-gear, and you shift around the same time as the stocker. So every gear you put distance on him. Have been doing this since 2005 with my E46 M3, and have all the data to prove it. And no, there is no issue with the valvetrain when revving higher. Over a sample of 3 cars we have tested over 130 000km of revving 8500-8600 every day for 3 years with no ill-effects. Schrick state the stock valve springs are good for 8800rpm on the S54.
This is apples vs oranges - apples vs apples is if I raise the rev-limiter with the stock FD ratio as well - then the same arguments still apply.
I can definitely see the need for a higher FD ratio in the MT transmission - the gearing honestly was too tall for me coming from the shorter geared RS4 transmission. The problem I have is paying for it as an aftermarket modification for the street - I know in reality it doesn't actually make the car faster in many scenarios (like actually adding power to the engine does in ALL scenarios) and I certainly feel it is the ratio that BMW should have offered on the car from the factory.
I guess it's like paying for coach vs business class - I won't actually get to where I'm going faster, but the experience no doubt will be better.