There isn't much use in making a high-revving M54. The block isn't stiff enough to rev reliably past 7,000 unless you put some megabucks work into it. You'll be eating OPNs and rod bearings for the rest of time to make another 30-40hp and it'll all be up top - not much use on the street. We rev the DSP car to 7k and I still worry about it without a damper on there.
Originally Posted by serdar255
I want to do cams, Idk if i should do a custom turbo as i originally planned or do a high revving NA set up, but that would cost more in the long run.
If you're really sold on going NA, best bet is to do an S54 swap. The iron block in that motor is designed to take the revs and the head flows very well from the factory.
'03 330i ZHP - Stock-ish
'02 330Ci - Megasquirted, E85'd and tuned by PFTuning.com
Last edited by SoloII///M; 12-26-2012 at 02:14 PM.