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Old 01-31-2005, 10:21 AM
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iateyourcheese iateyourcheese is offline
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Join Date: Sep 2004
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Quote:
Originally Posted by Fifty_Cent

Z3 1.9is, 140 hp, 73.68bhp per l
Z4 2.2i, 170 hp, 77.27 bhp per l
S2000(Honda), 240 hp, 120bhp per l


Now tell me, which is the most technologically advanced engine????
This goes with the "does horsepower per liter matter" discussion above. I guess it does from a marketing perspective, but a better car it doesn't necessarily make.

Both the Z4 2.2i and the S2000 have roughly the same size engine (2171 cc vs. 2157 cc respectively) so let's compare the two.

BMW seems to optimize their engines differently than Honda. BMW likes to make engines that develop their torque early and deliver it consistently while trying to be reasonable on the fuel. Honda makes engines that are higher in HP but develop their torque later. This leads naturally to high MPG.

At 3500 rpm the BMW engine makes 155 lb-ft of torque whereas the S2000 makes 140. This is also the peak for the BMW, but looking at a dyno you'll see that it's pretty flat across the whole range. The Honda has a peak torque of 162 lb-ft (only 4% more than the Bimmer) at 6500 rpm (you'll see the torque and horsepower jumps when you get above 6000 rpm, I assume they change the intake somehow there).

So who makes the more technologically advanced engine? Umm... I'd say they make two very different engines. BMW provides its torque early and its horsepower linearly, while the S2000 acts like two different engines. Below 6000 RPM it's nothing special (150 hp @ 6000 rpm), but above 6000 it starts cranking out all of the power. This seems to be their way of getting good gas mileage while still being able to claim 240 hp.

I hope you don't see this as a fanatics reply. Until we get the super transmission from the future, torque is still very important.
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