I have a 2006 Z4M andI would like to know if anyone knows of any literature or spec information regarding how much horsepower the inline six can handle without having to modify internals.
depends on how you go about it. With the s54 450-500 at the crank is pretty common. That's with a bolt on Vortech centrifugal, and ecu tuning of you choice, Dinan, AA, RMS, ect. There are E46 M3's that put out 800+ at wheels from Horsepowerfreaks.com , but I don't know if you got 35k to spend.
Active Autowerke SC - 460 to wheels Runs fairly strong http://www.mcoupe.com/video/bmw-m-coupe-dyno - AA Supercharger with Alcohol Water Injection - AA Intake Manifold - Active Stage III Software - AA Intercooler - AA Oil Cooler - AA Clutch Assembly - AA Headers and Track Pipe - Denso Iridium Plugs ( www.densoiridium.com ) - Supersprint Stainless Steel Exhaust
color did you repaint your car? You have my dream car. I use to have a 2001 Z3. Burt fell in love with your style of car.
The color of the avatar Yeah, what gives with what looks like Phoenix Yellow, aka Baby Puke Gold? Is your "clown shoe" from BMW Individual? I thought only the E46 M3 came in Phoenix Yellow (which, I have to say, is beginning to frow on me. Don't tell Mom).