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If yes, Mercedes managed something unusual then. Generating most downforce at low speeds with the longest wheelbase and lowest rake.godlameroso wrote: ↑07 Dec 2019, 21:28Why would a team choose high over low rake? What considerations does one need to take for the rest of the chassis in order to use one philosophy or the other? The higher the rake the closer the front wing is to the ground, the closer the T-tray is to the ground, and the higher your diffuser and rear wing. The rake of the car changes at speed because of the aero loading, it also changes under braking, and acceleration, and transient maneuvers. So depending on setup your static rake could be no rake at all at speed, or less rake, or more depending on the onset of aero loading. Rake also has the effect of determining how soon you can create meaningful downforce, higher rake tends to produce more downforce at lower speeds, but stalls at higher speeds. Lower rake has the opposite effect, being more stable at higher speeds, but not generating as much downforce at lower speeds. Rake is also dependent on wheelbase, because the length of the floor, or the size of the bargeboards is influenced by the length of the car.
With a higher rake, smaller wheelbase car you depend more on the front end of the car to seal the sides of the floor, and limit the amount of airflow you can feed the diffuser. With a lower rake, longer wheelbase car, it makes it slightly easier to seal the sides of the floor with the bargeboards, so you can divert more airflow to the diffuser.
Another benefit of a longer car is that it can be made thinner as a result.
They found the right compromise. They leaned on their mechanical grip at low speeds, and bolted on all the downforce they could. Besides less rake doesn't mean low speed downforce vanishes, it's just a relative POV.LM10 wrote: ↑08 Dec 2019, 01:21If yes, Mercedes managed something unusual then. Generating most downforce at low speeds with the longest wheelbase and lowest rake.godlameroso wrote: ↑07 Dec 2019, 21:28Why would a team choose high over low rake? What considerations does one need to take for the rest of the chassis in order to use one philosophy or the other? The higher the rake the closer the front wing is to the ground, the closer the T-tray is to the ground, and the higher your diffuser and rear wing. The rake of the car changes at speed because of the aero loading, it also changes under braking, and acceleration, and transient maneuvers. So depending on setup your static rake could be no rake at all at speed, or less rake, or more depending on the onset of aero loading. Rake also has the effect of determining how soon you can create meaningful downforce, higher rake tends to produce more downforce at lower speeds, but stalls at higher speeds. Lower rake has the opposite effect, being more stable at higher speeds, but not generating as much downforce at lower speeds. Rake is also dependent on wheelbase, because the length of the floor, or the size of the bargeboards is influenced by the length of the car.
With a higher rake, smaller wheelbase car you depend more on the front end of the car to seal the sides of the floor, and limit the amount of airflow you can feed the diffuser. With a lower rake, longer wheelbase car, it makes it slightly easier to seal the sides of the floor with the bargeboards, so you can divert more airflow to the diffuser.
Another benefit of a longer car is that it can be made thinner as a result.
I thought the front wing had a set minimum height while the car is static. Therefore the rake won't matter, the front wings will all be at the minimum height. Or is that completely wronggodlameroso wrote: ↑07 Dec 2019, 21:28Why would a team choose high over low rake? What considerations does one need to take for the rest of the chassis in order to use one philosophy or the other? The higher the rake the closer the front wing is to the ground, the closer the T-tray is to the ground, and the higher your diffuser and rear wing. The rake of the car changes at speed because of the aero loading, it also changes under braking, and acceleration, and transient maneuvers. So depending on setup your static rake could be no rake at all at speed, or less rake, or more depending on the onset of aero loading. Rake also has the effect of determining how soon you can create meaningful downforce, higher rake tends to produce more downforce at lower speeds, but stalls at higher speeds. Lower rake has the opposite effect, being more stable at higher speeds, but not generating as much downforce at lower speeds. Rake is also dependent on wheelbase, because the length of the floor, or the size of the bargeboards is influenced by the length of the car.
With a higher rake, smaller wheelbase car you depend more on the front end of the car to seal the sides of the floor, and limit the amount of airflow you can feed the diffuser. With a lower rake, longer wheelbase car, it makes it slightly easier to seal the sides of the floor with the bargeboards, so you can divert more airflow to the diffuser.
Another benefit of a longer car is that it can be made thinner as a result.
The way I see it, high Rake gives you a larger range of rear wing angle Delta. If both a high rake and low rake car have the same rear wing angle at a stand still, the high rake car will have less rear wing angle at full squat than the low rake. If the only variable between the 2 cars is the rake, the high rake car should be able to achieve higher top speeds while maintaining the same amount of DF at slower speeds.LM10 wrote: ↑08 Dec 2019, 01:21If yes, Mercedes managed something unusual then. Generating most downforce at low speeds with the longest wheelbase and lowest rake.godlameroso wrote: ↑07 Dec 2019, 21:28Why would a team choose high over low rake? What considerations does one need to take for the rest of the chassis in order to use one philosophy or the other? The higher the rake the closer the front wing is to the ground, the closer the T-tray is to the ground, and the higher your diffuser and rear wing. The rake of the car changes at speed because of the aero loading, it also changes under braking, and acceleration, and transient maneuvers. So depending on setup your static rake could be no rake at all at speed, or less rake, or more depending on the onset of aero loading. Rake also has the effect of determining how soon you can create meaningful downforce, higher rake tends to produce more downforce at lower speeds, but stalls at higher speeds. Lower rake has the opposite effect, being more stable at higher speeds, but not generating as much downforce at lower speeds. Rake is also dependent on wheelbase, because the length of the floor, or the size of the bargeboards is influenced by the length of the car.
With a higher rake, smaller wheelbase car you depend more on the front end of the car to seal the sides of the floor, and limit the amount of airflow you can feed the diffuser. With a lower rake, longer wheelbase car, it makes it slightly easier to seal the sides of the floor with the bargeboards, so you can divert more airflow to the diffuser.
Another benefit of a longer car is that it can be made thinner as a result.
