Originally Posted by swamp2
...The single most impressive thing about the S65 engine is the shape of its torque curve. Of course ultimately peak power is way more important than peak torque (how many times have we have that debate here...) but what the M3 achieves is roughly 90% of peak torque from 3000 rpm up to just a hair shy of redline. In that band the torque curve looks like a frikin' table top. There is not really a match for this achievement anywhere in the market and to get even close you have to spend about 300%. Of course the redline itself is impressive as well as it specific output (however, hp/l is more important from a technical perspective rather than from a what really matters in an engine perspective). When it came out I think there was one car (Ferrari) with a higher redline. What does this torque curve mean in the real world? It provides wonderful engine feel, control and incredibly linear (constant) acceleration. Choose the right gear and the engine provides the same punch across an enormous rpm range.
Agree on everything, but the last line is bolded for a reason...
Originally Posted by swamp2
We've also beat the horse to an absolutely bloody pulp on the issue of so called "lack of torque" in the M3. There is no lack of torque, there is insistence by some to be a "lazy driver", essentially in the wrong gear. Now to some, that type of performance has definite value but that is not the same as a lack of torque. Torque to the wheels is what counts, torque at the crank is a truly a meaningless spec, you can't feel it nor measure it, the transmission must be involved in addition to crank torque to be meaningful in any way. Then you are talking (more or less) about power. At the wheels the car has more torque than many Vettes (don't remember the details but the calculations have been shown here on the forum)...
Without trying to re-light another flamefest, one has to set a context here. Most folks equate torque with how a car feels at the low end of the rpm band, as opposed to some peak torque value.
In this context, your posted chart shows what every driver feels when driving a current M3, where the steep torque curve at lower rpm is definitely noticeable. It's sullen at 1500, willing at 2000, transitioning to eager at something below 3000 rpm (for me, the crossover seems to be somewhere around 2600), and absolutely joyous at 4000 and up.
Because of the steep gearing, it's easy to drive around this "weakness", and in fact I think most drivers simply don't notice it because they instinctively know that rpm is the solution to the problem at hand, and rpm is exceedingly easy to obtain in this car.
In addition, this "issue" is really only noticeable when one is comparing the car to others that are considered to be competitive to it in some way. The C63, Vette, etc. have low-end responsiveness in spades, but it's only in that context that the M3 shows a little weakness. In point of fact, there's no real weakness in everyday driving, and the car is a pleasure to pilot almost anywhere in the rpm spectrum.
Furthermore, with the auto there is simply no issue at all because of how responsive that box is to driver demands. It's only the six-speed cars where this relatively minor issue may show up from time to time - and then only when compared to other hot cars with more low end torque.