View Single Post
      09-30-2013, 12:13 PM   #139
swamp2
Lieutenant General
swamp2's Avatar
United_States
609
Rep
10,407
Posts

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

iTrader: (3)

Quote:
Originally Posted by Jonjt View Post
...
In other words, because power (unlike torque) is conserved in a drive train (Pwheel=Pengine-(Pwindage+Pfriction+Ppumping+Pinertial+Pmiscellane ous in all gears), you shift when the power available to move the car forward is higher in the higher gear than it is in the lower gear.
...
This was my main point. It is certainly possible to characterize tractive effort and shift points as a function of engine torque. But why? It requires extra computation and, is largely beyond the purview of the average M3/M4 owner. The easiest method to determine shift points would be to say to the owner, “when power available to more the car forward in the lower gear is less than that available in the higher gear, shift.” That is why I said one should concern themselves with power, in this case.
Nice glaring contradiction...

You claim power is conserved then provide an equation showing how power is not conserved (we all know it is not based on dynos).

And you still think you can calculate shift points without knowledge of RPM DEPENDENT parasitic losses using crank power only?

Sorry bud, I am not going to wade through the rest of your analysis to find any other major errors or contradictions. Calculating shift points exactly just isn't trivial for the average enthusiast. Luckily many of us can still do a reasonably good job by feel alone.

Use your "method" to show me exactly how to calculate shift points for any car where the exact shape of the power or torque curves are known. Until then STFU, really, your foot keeps going deeper and deeper.
__________________
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK |
| Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors |
| Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels |
| XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit |
Appreciate 0