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      06-11-2013, 12:56 AM   #114
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swamp2's Avatar

Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

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Wow, where do I even start. As CanAutM3 mentioned, it does sound like you failed one or more of your "mechanics of force" classes. By the way I've never seen such a course title in any undergrad or graduate school engineering course catalogs...

Just for kicks though since you are degree dropping mine are in physics and mathematics and I've also worked as a Mechanical Engineer.

Originally Posted by flinchy View Post
i did offer proof

if you hold power flat from 6000-8000RPM, you will ALWAY NO MATTER WHAT shift at redline for maximum acceleration, as ONLY there will the next gear provide better acceleration
100% positively false. As I and CanAutM3 have shown, gearing is required information to compute shift points. Period. You've not shown jack but reference some random web pages with non verifiable algorithms...

Originally Posted by flinchy View Post
until YOU can show any evidence otherwise, that's the fact...
I've shown my evidence, what part of post #83 did you miss? This is pretty well equivalent to what CanAutM3 has shown. You agree with him and disagree with me? WTF?

Originally Posted by flinchy View Post
heck.. i just plugged a stock F10 dyno into MULTIPLE calculators (Like the ones i posted) and STOCK it's redline shifting, it's not until tuned (like the graph i posted) that the midrange overtakes.

calculation being performed via any number of calculators (spreadsheets etc.) that use various points of torque curves + gear ratios+FD to work out at what point it's more effective to change

i even posted links to EXACTLY what i was using.
Do they plot and show potentially intersecting force at the wheels as a function of speed gear by gear? Until you can plot those and compare with mine we don't have any basis for comparison.

Originally Posted by flinchy View Post
LOL it sounds like you're the one lacking understanding

you should google:


an article on 'the other site'

a crutch for truly understanding power? yeah no, more like how power actually works

power is torque over time (ie at an RPM), torque is power without time (hence torque is also called a 'moment of force')
anyone who disagrees with the above is simply wrong, as they can't prove anything otherwise (and conversely, proof in abundance for the CORRECT case)
You should google the plethora of good and lengthy debates here on this forum about power vs. torque. You clearly don't get it.

Let's review 100% independent of torque and gearing! Two cars A and B at the same speed and same weight. The car that can produce the most power (to the wheels of course) at that speed will always out accelerate the other. Period, no if's and's or but's

The problem is many peoples understanding is reconciling that statement with the additional fact that peak in gear acceleration (less some drivetrain inertial effects) occurs at the rpm where the peak torque is produced.

Hint: At a given speed a lower gear may be available which will often increase rpm, power and torque (to the wheels, the only place it matters, all the while REDUCING it at the crank)

Once you truly understand both of these statements (in bold above) and the fact that they are not contradictory, you may finally understand why power is both more important and more fundamental in vehicle performance.

Power is not torque over time. Power is fundamentally a product (literally multiplication or vector dot product) or a force and a velocity. In the case of rotating things the velocity is and angular velocity or rpm.

We are really digressing here into a debate I'm really quite tired of having...

Originally Posted by flinchy View Post
but you seem to be lacking core understanding of torque+power+gearing+acceleration etc relationship.
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Last edited by swamp2; 06-15-2013 at 02:27 PM..
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