Quote:
Originally Posted by Ryephile
The HKS video has been interesting as it markedly differs from the advertised power curve, falling off sharply at higher RPM. Does this represent final engine spec?
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Doubtful. For your plot, you used one of the early guesses for scale of the the screencap. I used the same scale for the plot titled "2004 WRX and BRZ (unrealistically optimistic) Estimated Acceleration vs Speed" (in
post 175).
I threw that plot out because it shows the car making its peak power too early, and working backwards the engine would need to make 167-171 lbf*ft for 4500-6300 RPM. So either that's not the right scale, or the dyno is from early testing, or this engine is way under-rated. I wouldn't count on the last one, and I only included that plot in my post to illustrate why that guess for the scale appears to be wrong.
Quote:
Originally Posted by Ryephile
This is strange for a gasoline production car, to have to upshift prior to redline to get peak accelerative force.
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It's likely just the wrong scale. Try plotting again with the scale shown
in the revised first post in that thread (where peak power is actually at 7k) and you'll get more reasonable results (like my "conservative dyno" plots).
Though it's still not quite right... we won't know exactly what the story is until we see some properly labeled dynos.
Quote:
Originally Posted by serialk11r
So when you account for aero the higher the speed, the more drag, so the lower the acceleration, so each of those lines starts to go down a little, and the shift points move up a bit, but on Deslock's chart there is still the shift before redline phenomenon.
I guess the weird drop off >7000rpm is something that can only be explained when the cars start arriving.
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The shift points don't change due to drag. You upshift when you put down less power in the lower gear than you will in the higher gear. The only plot of mine that shows shifting before 7450 is the one I discarded, for the reasons mentioned above (all my other plots show the car being shifted at redline).