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Old 03-09-2015, 07:56 PM   #2339
Jawnathin
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Quote:
All you are seeing in my original posts are results, not the calcs. To expand on my brief introduction:
Ok, that sounds really complicated, I'm not sure how you could accurately measure the effects of some of these factors...
  • Example 1 - Rolling resistances: different tires have different rolling resistance, they get softer in the heat, harder after getting worn, etc
  • Example 2 - Drag: Exhausts, wheel design/offset, tire width, FRS vs BRZ bumpers/spoilers all have influence on the aero of the car.
  • Example 3 - Torque curve per RPM without the CSV or spreadsheet detailing the exact value at those RPMs. (Maybe you have that somewhere? Maybe you went pixel by pixel for close enough approximation?)

...and without understanding your formula and how each factor is weighted, I'm naturally a little skeptical. It isn't skepticism of you or your effort, I appreciate the contribute and discussion, its just this calculation is unknown and without validation of any type to ensure accuracy. Hopefully you understand where I'm coming from, but let's go with it and see where we end up.

BTW, did you also factor in the gravitational pull of Mars?

Quote:
I'd say most Pro courses are pretty representative of national courses, just shorter. Obviously, if you have 2x as many FT zones, the reported differences could be multiplied 2x, but will still be <~0.1 sec.
Well I was thinking of the drag strip start being a little different from your typical NT event. But yes, the primary difference is that they're shorter, 35~ seconds vs 60~ seconds or so, so there may be double the number FT zones. Can also x2 for each side (on a pro) or each day (for a tour/Nationals).

Quote:

All my data is OBDII data as recorded by solostorm as well. The throttle reported is ECU commanded. I can guarantee that is not me dropping the throttle to ~18% in the 14-15 sec timeframe in the plot above.
What do you think about looking at 90%+ or something for commanded throttle for acceleration runs? I think the ECU does something funny with its commanded throttle calculation. I took a quick look at one of the logs and in different parts of the run I was able to have several duplicate 98.5294117647058 and 97.0588235294117 commanded throttle position entries. Not sure if it blends it with a previous sample or if I was really able to nail town 98.5% instead of 100%. I have a few other entries of very high throttle % where I'm sure the intent was WOT and the car is being fed all the air it can take anyway.

If you wanna take a stab at my logs I can send them over. Let me know and I'll PM you with a way to get them. This might be going a little far, but if it isn't much to do three different events, I'd like to see how they turn out. One is from the long runway course (the course I described above) and the other is a 'square' site that is decently open but not quite as fast as the runway is. I should have some data from the 'fast' course on that site where I end up on the rev limiter a few times and data from a pretty slow course where I'm still a few hundred RPM off. I'd be curious to see what if any differences between the three different course/runs are.
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