Thread: S65 vs. S62
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      01-22-2013, 03:12 PM   #61
bruce.augenstein@comcast.
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This post is incorrect in many (but not all) of its points.

Quote:
Originally Posted by Munit View Post
well your post shows exactly the misunderstanding you and people have. You said torque is not relevent when you are taking to redline?
Torque isn't at all important when you are at redline. At any given speed, it's power that matters.

Quote:
Originally Posted by Munit View Post
That makes zero sense. Wheel torque aka thrust is at its peak at redline. Engine torque is also near flat and the same at redline as it is throughout the band. The difference is the combination of the effect of the revs coupled with the gearing which DRASTICALLY changes what is measured at the engine.
Torque at the drive wheels is what ultimately can accelerate the vehicle, but first of all, wheel torque is not at its peak at redline. It peaks in any given gear at the engine's torque peak. At any given vehicle speed, however, wheel torque (therefore the ability to accelerate) will be maxed at the power peak.

Quote:
Originally Posted by Munit View Post
Wheel torque is ultimately taking an engine making X amount of ability to drive an axle (torque). Then to translate into what actually gets the wheels you need to factor in the revs which obviously are not even part of an engine torque number, then as important or more is the effect of gearing which drastically varies depending on the type of engine. After that and you subtract the parastici losses, you get how much power the wheels are turning at or wheel torque/thrust. This last piece is all that matters.
A vehicle's ability to accelerate at any given speed is essentially governed by its power and by its weight. Torque, gearing and engine speed (RPM) are essentially immaterial in that context. Yes, you can go about calculating wheel torque at any given vehicle speed, but horsepower is the great shorthand in this context. More power gives you more wheel torque at any given speed, so why bother with those extraneous calculations?

Quote:
Originally Posted by Munit View Post
So yes at very low rpms the m3 has no wheel torque, but given the design, it also is very easy to get into 5500 plus powerband and at that point the wheel torque is more than a 335.
Agreed entirely. Since wheel torque is governed directly by power at any given speed, the M3 wins, especially on the right-hand side of the tach.

Quote:
Originally Posted by Munit View Post
So really it comes down to lazy drivers who for some reason want to be able to accelerate on the freeway in 6th or 7th without shifting vs someone who shifts to 3rd or 4th and takes a bit of effort.
Tend to disagree. I haven't bought an automatic for my own use since 1970, and still like to shift, but for me, having more available torque (meaning more power) while cruising means that I may very well be able to slot into that transient opening in the next lane without having to lose the second or so needed for a downshift - during which I am actually slowing down. Capiche?

Quote:
Originally Posted by Munit View Post
I totally understand if you are a lazy driver as that is what cruising is about-but in that case I really feel people bought the wrong car if they chose an m3.
Not sure I agree. I think the M3 is quite good at fairly low rpm in gear. Reference Car & Driver's 30-50 and 50-70 mph times in high gear with the manual box, and compare those times with other stick cars.

It's just that, when you're way over on the right-hand side of the tach with things getting all blurry and you're laughing like a loon, the low end feels as if it was way weak.

Quote:
Originally Posted by Munit View Post
An m3 is designed as something assumed will be driven for performance. When driving it for performance, the needle stays above 6k and you are paddling/rowing gears and low end torque is irrelevent.
Agreed entirely.

Quote:
Originally Posted by Munit View Post
ANyway what does it matter lol
Given the traffic in this note, it seems to matter a lot.

Not for the first time, let me post a pointer HERE for more info on horsepower vs torque.

Bruce

Last edited by bruce.augenstein@comcast.; 01-23-2013 at 01:13 AM. Reason: Spelling
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