Originally Posted by kotik
i think it's 6.2 still, but some different tech in it (4 valves and some other alien tech). It gets like 450hp/450tq vs the c6 is at 436hp i think.
still a two valve pushrod which has its advantages and disadvantages. very compact and light weight for what it does. it does have DI and a lot of combustion chamber optimization.
i've put about 15kmiles on my C6Z. seriously considered buying an e92M DCT a few months back; between that car and my friend's e92M with a manual trans, i have a couple hours' seat time in the M.
1) both Ms are stock. no 600hp insanity.
2) C6Z absolutely dominates the M on the performance front. much better brake feel, spectacular on the twisties, and the obvious power advantage. especially when one isn't in the RPM zone the M needs to be in to move.
3) M seats and interior in general dominates the Z.
4) the 1980's F15-looking HUD in the Z is surprisingly useful. wish the M had one.
5) i really like the driving position and shifter in the Z.
6) M is a 'nicer' car. cool headlights which follow the steering, trick exposed CF roof, trick gauges with the shift light, incredible seats, DCT. all the cool nuances of a BMW.
7) Z's weight and center of mass advantage shows up any time you stop, go, turn.
8) M engine sounds wicked at idle. i've been told the Z sounds pretty wicked from the outside, but from the inside, it sounds very tame. although the accelerations are anything but tame.
9) the Z totally comes alive in the twisties. i haven't driven another car which comes close.
10) for anyone considering a Z, good tires are a must. i put pilot super sports on it (ditching the supercars) and the car went from scary (and not in a good way) to extremely predictable and fun. and it could finally put down power, even in first gear.
my Z is presently parked and i have 2500$ in Ti valves on order. it can be done more cheaply, but my goal is to keep things stock without increasing the exhaust valves' mass since IMO this engine is somewhat critical on that front. also, it is my opinion the moly coating will be necessary on the intake valves when going to bronze guides, therefore 16 new valves. IMO, the exhaust valve issue is a real thing and i am dropping the $$$ to preemptively correct it. one detail tho: i have 15k miles where the car only demanded tires, gas, and oil changes. it's been very reliable.
these cars will often be at the same price point depending on year, miles, and condition compared. get the M if you want a capable car which is also a very nice car. get the Z if you want an incredible grin machine. i intend to add an e92M (replacing my 330ci) and own both in a few years.