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2021 Rules Time--How about no changes?


Greg G.

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NorcalTT

re: flat power curves.  having had both, i can tell you that what matters is the area under the curve. whether it's flat or not is a function of how you decide to maximize that area.  same car, same weight, same avg hp will show the same accel/speed traces in the data. the WRL rule is ridiculous

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Tansar_Motorsports

Theoretically, I would argue that for a power limited car (low power, lots of tire), a flat power curve would be beneficial, and for a tire limited car (high power and/or not enough tire), a traditional sloped power curve would be beneficial.

Why...

The low power car can easily use full throttle when leaving a slow corner.  having more power (and thus generating more energy) at the beginning of the straight is more valuable than at the middle or end of the straight, because the acceleration that it generates then pays dividends all the way down the straight.
Additionally, a flat power curve may allow you to downshift less, and therefore upshift less on the following straight, saving time.

The high power car would struggle to use full throttle when leaving a slow corner.  Therefore, having a flat power curve would be useless, because they would then be able to use even less of the throttle %, so that potential power would be lost.  Therefore, over the course of the straight, they would end up generating less energy, and therefore less acceleration than if they had had a traditional power curve.

 

Of course, overall these differences are miniscule, and ST should not have a flat power curve modifier. 
The current average HP calculation method does a very good job of creating equivalence between different engine types.

For WRL, where most cars are lower power, I can see how this type of rule might be beneficial.  I am not familiar with their power/weight calculation method.  If they are just using peak HP, and then adding on this flat power curve modifier, then that makes sense.  But we don't need it.

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WRL uses weight / peak power plus modifier.  So a 2800 lbs car with 241 horsepower and up to -0.4 modifier would be 11.2:1.  Or, with a traditional power curve, it could make 250rwhp.  That's really not much of a penalty for having a flat power band.

Using the ST4 formula, assuming a >7k rev limiter, a 2800 car with a flat 241 power band would be 11.6:1.  A traditional power curve with, say, a 20 hp drop every 1k RPM could make 223 @ 6250 and 259 @ 8000 RPM.  (223 + 228 + 233 + 238 + 244 + 249 + 254 + 259).

So the ST rule has a greater penalty for flat power band cars than WRL already.  Plus it doesn't have any ambiguous language like "flat horsepower power curve."  (what's flat?  1 rwhp drop over 500 RPM ok? 2 rwhp?)

 

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