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      03-24-2007, 05:41 AM   #28
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Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

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Weight, mpg, etc.

Originally Posted by e36jakeo View Post
This whole engine comparison winds up confusing me. If the above figures are correct for MUCH larger and torquier engines that are also just as fuel efficient (or more so) as the M3's V8, what is the TRUE point of a high-revving design? Less torque does allow for a lighter weight drivetrain, but then the M3 will still weigh a lot more than a GT3, Z06, etc.

I'd love to see a breakdown of how much lighter the engine, transmission, axles, gears, clutch, etc. etc of BMW's high-revving M3 vs. the Z06's "old school" pushrod 7 liter V8. The immediate 470 lbs ft of torque in a Z06 makes it really fun to drive with friends -- just to whip their head back!

If you compare an F430's 483 HP V8 to a Z06's 505 HP V8, the Z06's V8 makes more torque, more HP, weighs almost the same (based on above numbers), yet gets dramatically better fuel economy (16/26 vs 11/16 for the Ferrari).

If revs cost in gas and in torque and (it seems) don't benefit much in weight., what is the point?
MPG in a large displacement engine simply comes from running at extremely low rpms (and tall gears) 4l @ 3k rpm is using more fuel than 8l at 1250 rpm. Purpose of a high revving design is to win a road race (not nec. a drag race). High revs, lower torque = lighest weight engine, drive train and chassis.

You don't see any high displacement torque monster engines winning at elite levels of racing do you?

All that being said the Z06 is a nice package. One way it's engine saves weight by having much less complex/bulky heads and one cam. It will be punished by other drive train components being really strong (heavy) to handle the monster torque. Even with that penalty the Z06 is designed from the ground up to be lightweight sports car and the engineers really achieved something. M3 will also be designed to be light too but it is a 4dr and simply a bigger car. The engine and drive train in this sense will be a bit unmatched to the chassis. The engine and drive train truly belongs in something like a Lotus chassis. Wouln't that be fun....