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[QUOTE]Originally posted by st5150: [QB] Okay.... done. I have a rough program on my graphing calculator that determines optimum shift points now. Here is what it does... -took RPM vs HP data from bunchmyfunky's dyno graph and used a curve-fit program I found online to represent his HP curve as a third degree polynomial (HP=A*RPM^3+B*RPM^2+C*RPM+D). The coefficients (A, B, C & D) are really ugly, but the the polynomial proved to always be with in 2 HP at almost all points of bunchmyfunky's dyno graph. Accurate enough for our purposes :) -now that we have this equation, we have to derive the intergral of it between two RPM's. The upper limit of this intergral is easy... it is our shift point. The lower limit however is the RPM his motor drops to after a shift is completed. It is a function of the shift point, and the transmissions gear ratios. I calculated the the optimal shift point on the 3-4 shift.. so the lower limit is: shift_point-(shift_point-shiftpoint*4th_gear_ratio/3rd_gear_ratio) -yes, we have one ugly intergral on our hands. I don't feel like typing it out, but trust me, its ugly... but not difficult. -now I just entered in the gear ratios (1.33 for 3rd and 1.00 for 4th) and the shift point and have the calculator perform the intergral for me. -I kept entering a new shift point and had the calculator tell me the "area under the curve" for that shift point from 3rd to 4th gear. The larger the number, the larger chunk of his motors powerband was used. -Results? 6550 RPM provided the largest area under the curve for the 3-4 shift! -Analysis? Like I said before I spent over two hours working this out by hand(and calculator)... you really need data at least 500-700 RPM past your peak HP RPM to determine your optimal shift point. In this case, the polynomial projection isn't accurate (doesn't drop off fast enough to accurately represent bunchmyfunky's powerband) after 5800 RPM. However, it implies that bunchmyfunky's 3rd to 4th gear shift should be a fair amount past 5800 RPM. -Conclusion: EXCEL and any other microsoft product is a freak'n joke. I initially used it to derive the polynomial and after an hour of wondering why my model to solve this problem wasn't working... I realized bill gates' POS program gave me a BS polynomial! Foolish of me to think I could use any microsoft product to get a dependible and accurate result! :mad: -Final thoughts: You really need the "big picture" on the dyno if you want to determine your shift points from it. -Translation? REV IT UNTIL THE HP REALLY STARTS TO DROP on the dyno so you can get the proper data to determine your shift points :D [/QB][/QUOTE]
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