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Old 01-22-2013, 12:55 PM   #46
DSilk56
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Join Date: Nov 2010
Location: Miami, Florida
Posts: 798
My Ride: M-3 Convertible
Quote:
Originally Posted by TerraPhantm View Post
Probably stuck in limp mode or something. When my throttle position sensor failed, it felt about as slow as my ZHP did.




Actually, it's got plenty of low-end torque. That's not opinion, that's fact. The car makes ~85% of it's peak torque from 2000-7000 RPM. Its peak torque is 262 lb-ft -- quite a bit for 3.2L. It makes more torque than the honda accord does with 3.5L, and the S54 holds onto said torque for much longer than the accord.

3rd gear in the M3 goes to right about 100mph. So even if the Accord's instantaneous acceleration is somewhat close in that gear, it will have to shift while the M3 will be able to keep going.
The M3 is not a torque monster by any stretch of the imagination. Saying that it has more torque than a Honda Accord is like saying that Justin Bieber weighs more than Natalie Portman. It may be true, but it doesn't make either of them heavyweights.

As a general rule, normally aspirated engines need large displacement to generate large torque numbers. It's relatively simple. Torque is a measure of the twisting force exerted on the crankshaft by the connecting rods, and this is limited by the amount of explosive force harnessed in each cylinder. The more fuel effectively exploded, the more force available.

Unless you use forced induction, it is tough to get a lot of torque from a relatively small engine. 263 lbs./ft. from 3.2 litres is good, but doesn't compare to the 290 lbs./ft. that the 2.0 litre turbocharged engine in the Subaru WRX-STi makes or the 390 lbs./ft. that the 5 litre V8 in the Mustang GT makes.

Horsepower is a more complicated matter, as it is a measure of work done over a set period of time, as opposed to a measure of force. To put it in more pedestrian terms, a weightlifter who can pick up a barbell with 500 lbs. of weight and move it 10 yards in 1 minute has performed the same amount of work as the sprinter who can make the same trip 10 times in the same minute laden with 50 lbs of weight each trip. The weightlifter performs the work by exerting substantially more force at a slower speed than the sprinter. In our example, the M3 is the sprinter. It relies upon its ability to rev to very high rotational speeds while still developing usable torque, while the larger displacement Mustang relies upon brute force, and doesn't need to rev to particularly high speeds to get the work done.
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