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      06-11-2013, 09:51 PM   #119
Brigadier General

Drives: 130i
Join Date: Nov 2011
Location: QLD, Australia

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Originally Posted by swamp2 View Post

100% positively, FALSE. The acceleration curve "mirrors" the torque curve and this comes fundamentally from F = ma. You can also grab the more detailed formula 2-9b from the Gillespie text book, Fundamentals of Vehicle Dynamics. Again ignoring the (typically) minor corrections in the second term, the peaks corresponding become obvious. Please stop while you are ahead. You can also spreadsheet up this type of solution as many forum members have done themselves to see this point. Each ongoing post here makes you look all the more incorrect and quite frankly ignorant.
ahahahahah ok, until you sit down and learn the fundamentals, this discussion is over. it's hilarious you've managed to so deeply convince yourself that what i'm saying isn't correct... peak power at redline increasing steadily with a torque taper, yet you'll accelerate faster while producing less power at peak torque in the midrange? hahah

i think i just realized we were having two simultanous separate arguments.

every evo owner ever disagrees with you

same for GT-R's, RB's and 2j's...

even formula 1 cars disagree with you (peak torque some 2000rpm before redline)

Originally Posted by swamp2 View Post
Really, WTF, I can't even understand this gobbeldy-gook
yeah it makes sense how you're not understanding when you lack such basic reading and comprehension skills.

Originally Posted by swamp2 View Post
Again no. RPM is in no way equal to or equivalent to time. Yes time must march along in the background, in the same way it does for most simple Newtonian mechanics problems, for something to spin in the first place but that's about it.
got it, 'minute' isn't a measurement of time.

Originally Posted by swamp2 View Post
No, no, no. I insist on keeping it simple and focusing on concepts, pot meet kettle... Big fat chance on the second point. You language is so imprecise and has been riddled with errors. If you think that begets clarity you've got even more problems.

I'm far from perfect but here on this forum I do have a thrust and a bit of role as one who brings clarity and transparency to aspects of vehicle performance through correct science and math (often statistics or lack thereof). You've got a long way to go to offer any help or clarity here on these particular topics. Please, please for you own education.

Here are some pointers, thank me later for all of the solid materials here. PLEASE, PLEASE, save yourself, do some reading:

Does final drive really matter
Power to weight is the most critical metric in performance (late in the thread an agreement is finally reached)
Another like the above (particularly my post #134)
Peak in gear acceleration is (not quite) at peak torque
Bruce's good old write up on power vs. torque
The lack of low end torque in the E9X M3. #1 and #2
simple. right.

my language has been for the lowest common denominator who could be reading... inaccuracies? please.

most of those links are simply not part of this discussion.. re:diffs... shorter final drive will net better acceleration (minus shift times if MT) if you make peak power at redline.. longer final drive will net better acceleration if you have a 'peaky' power/torque curve (a la stock frame turbo N54... you'll find 60-130 type acceleration will be far superior in longer gearing like 2.56 compared to shorter like 3.46)

as for the "Peak in gear acceleration is not quite at peak torque..." thread..

you seem to simultaneously disagree with other points you've made in this thread... and agree with others of mine (re: peak power acceleration)

ED: yeah that post seems to flip back and forth with very unclear information.

i think we have been talking about two different things:... you peak acceleration at a specific RPM

me: still talking about when you should shift in a gear.

all i've been saying is it's impossible to have any change in gear ratio (longer) that will accelerate you faster assuming you produce peak power at redline.

Last edited by flinchy; 06-11-2013 at 10:07 PM..