1990's F1 Downforce (confusion)

[Testdrive]

You need a frontal area. Real or assumed, but the forces all depend on Cl AND the frontal area plugged in the formula. Is your mod defaulting to 1m2?

What I did, I used like depending on year EG CL = 2.47, L/D = 2.63 and set all wings to maximum, then did the wings test at 241KM down the straight, edited the aero files until I got those CL and L/D values in my wing test data. I then drove the car which was surprisingly stable and grip levels seemed realistic a lot less grip then usual , but on the straight, I was massively fast on the straight. I'm not sure about 1m2. not sure how the internals function. All I can do is edit aero of wings, body, lift, drag, engine power and tinker with the tyre grip.

[Testdrive]

You need a frontal area. Real or assumed, but the forces all depend on Cl AND the frontal area plugged in the formula. Is your mod defaulting to 1m2?

I just reworked the aero I went for 1111KG of downforce at 241KM with 37% frontal and lift to drag ratio of 2.95, this was with full front and rear wing. With this setup the Williams FW15C with 780HP at 14500RPM hits about 300KM on the straight. But by lowering the wings and hitting about 315KM, I don't have much frontal grip, specially at low speeds corners. I might have lower the diffuser and put more lift on front and rear wings. They tend to drop to 30% frontal at lower speeds.

[Greg Locock]

wagging figures from katz, looks like Cd of .5 gives a Cl of 2, and Cd of 1 gives a Cl of 3, for an optimal open wheeler (ie many fall under that line). This is obviously old data.

[JJR]

I remember plot of downforce over the years from Peter Wright. He plot downforce evolution from 1968 to 2000.
For year 1990 he plot value of 3100 lbs @ 150 mph and peak valuve was 3500lbs @ 150mph before Senna Imola incident:

1990 ..... 975kg@200kph ....CLA=5.35
1994 ..... 1100kg@200kph....CLA=6.04

And peak lift to drag ration in early 1994 was around L/D = 4,0

So it looks like that those downfore levels were verry close to 2017 - 2020 downforce levels.

[jjn9128]

I remember plot of downforce over the years from Peter Wright. He plot downforce evolution from 1968 to 2000.
For year 1990 he plot value of 3100 lbs @ 150 mph and peak valuve was 3500lbs @ 150mph before Senna Imola incident:

1990 ..... 975kg@200kph ....CLA=5.35
1994 ..... 1100kg@200kph....CLA=6.04

And peak lift to drag ration in early 1994 was around L/D = 4,0

So it looks like that those downfore levels were verry close to 2017 - 2020 downforce levels.

3500lb at 150mph I get CzS 5.72 not 6.04?? I know it's Peter Wright, but what's the source for those numbers? Just pulling something out of the air? Team? Also is that including car and driver? Can assume ~625kg (1350lb) for a 550kg car plus 70kg driver with some fuel - CzS = 3.51 or Cz = 2.4 based on 1.47m^2, which is closer to the numbers from the Agathangelou paper.

[JJR]

I must check my "archives" to find the source of Peter Wright downforce diagram.

For CLA ( CzS) calculation I used air density of 1,18kg/m3.

[jjn9128]

I must check my "archives" to find the source of Peter Wright downforce diagram.

For CLA ( CzS) calculation I used air density of 1,18kg/m3.

Aaaah. ISA is 1.225kg/m^3