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Old 02-06-2013, 09:05 PM
m8o m8o is offline
Let me buya F31 335xi BMW
Location: 40*-55'-44" N / 73*-24'-07" W
Join Date: Oct 2009
Posts: 277
Mein Auto: 09 JCW, C43/55, 560SL, TJ
I've pondered the same question as the OP. It sounds like you need a copy of cartest2000. Great simulation program.

A few thoughts regarding the OP comes to mind you can prove-out with that program by simply customizing shift speeds and transmission parasitic losses and other losses.


1) Drag Time Calculator of old is likely invalidated by the most recent crop of transmissions and other efficiencies today's vehicles have over cars of old. They are far more efficient (having far less speed-based and rpm-based parasitic losses) than just a few years ago, let alone from what was the norm from decades ago when that algorithm Drag Time Calculator is based on; that stands for both the manual and automatic tranni.

2) The in addition, shift times are far faster in the automatics, so the loss that could accumulate measuring up to hundreds of milliseconds (if not over a second plus some) when shifting from 1 to 2 then from 2 to 3 then from 3 to 4 (tho many cars today pass the 1/4 mile right before the 3-4 shift) is only a fraction of what it was even just 5 or 10 years ago.

3) The F31 is quite slippery. Air resistance is really starting to play a role up at the trap speed of 100 or so mph. And the F3x of today is far slipperier than what was factored in to the algorithm Drag Time Calculator was based on.

4) I'm sure there are other things, like stock tire rolling resistance is far less than that of old?

But anyway, every one of those points will make a car get down the track far quicker requiring less power than Drag Time Calculator thinks it needs to attain the time and speed it does.

Last edited by m8o; 02-06-2013 at 09:17 PM.
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