12 replies to this topic

[Alekhine]

Hi

I did a surprising test in the Lotus setup.
I "abnormally"(?) Increased the camber on the left on Monza.
The result is surprising, the car is more stable when exiting a corner (on power), and it's more precise when entering a corner. I saved time too ...
I have always thought that you should not exceed +1° on interior of the tire, but maybe it's a mistake...

The best for me is +2 celsius in front, and +3 celsius rear.

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•  setup_gearbox.jpg   346.62K   61 downloads
•  more-camber__timelaps.jpg   127.07K   79 downloads
•  Front_2celsius__Rear3celsius.jpg   147.31K   72 downloads

Edited by Alekhine, Jan 14 2022 - 09:25 AM.

[John Woods]

Hm...DeepL is failing me.

Pretty radical setup altogether.

Thinking probably what is happening is you are taking the car past any normal limits, (wuhoo!), and you are finding GPL's capabilities exceed what is possible and "proper" IRL.

Guessing you may find other surprises.
Like...max spring theory?

Will try your setup today and see if that can keep me off the armco.

Edited by John Woods, Jan 15 2022 - 05:21 AM.

[Robert Fleurke]

Interesting Patrick, need to test it. Lee mentioned before that camber thrust is modelled in GPL, but I do not know up to what extent. I generally aim for 1 degree camber thrust as well. IIRC the highest number of temperature of the tire determines the grip level.

Possibly your grip level is slightly better due to temps of the tires, otherwise the extreme camber might just be better for the right handers...

[John Woods]

Robert Fleurke, on Jan 15 2022 - 04:51 AM, said:

...otherwise the extreme camber might just be better for the right handers...

Agree with that. The outside wheels get more vertical and more tire patch is applied to track.

As I understand reading Lauda, (even though his comments were kind of vague about it), there is a direct relationship between camber and anti-roll bars that must be in complement near maximum load or things can go way bad fast, or be really really good, and, if it has anything to do with bars, (my own theory), there is a direct relationship to toe.

What the heck is camber thrust anyway?

Edited by John Woods, Jan 15 2022 - 05:34 AM.

[Alekhine]

I don't think it's related to the temperature, because I notice a clear improvement in grip from the first lap (cold).  It’s therefore the camber itself that improves my setup.

I tested on Rouen, and it’s the same, 0,5s gain

[Arturo Pereira]

Extreme cambers are usual in setups for oval tracks, usually running counterclockwise. They are totally asymmetrical in almost every setting, including bump and rebound.

[lalb2001]

There is something to this.
My usual Monza camber setup with the Lotus is -0.90 deg at the front and -0.70 deg at the rear, so exactly -0.30 difference to what Patrick used. I just tried some laps on Patrick's server and the car feels much more planted with his settings. However the limit of slip/load on the tyre before I lose the rear is less predictable for me with the new settings. The feeling is a bit similar to that of a downforce car: As long as you keep the tyres within the grip zone, the car feels very planted, but when you go just slightly over the limit, you spin very quickly.

But maybe I just drove a bit sloppy and the higher camber is 100% faster? Not sure what to make of this yet. Also I need to try that same adjustment on other cars to see if they show the same behaviour.

[Alekhine]

I don't believe in chance. I haven't been able to go below 1.27.10 for months in 2020/2021.

In 2008 my PB was 1.26.53 but I was not 60 years old


A driver came to test different cambers on my server, he confirms to me that considerably improves stability.
The car doesn't go faster, but if you don't fight with it : you gain time...

lalb2001, on Jan 15 2022 - 07:18 AM, said:

There is something to this.
My usual Monza camber setup with the Lotus is -0.90 deg at the front and -0.70 deg at the rear, so exactly -0.30 difference to what Patrick used. I just tried some laps on Patrick's server and the car feels much more planted with his settings. However the limit of slip/load on the tyre before I lose the rear is less predictable for me with the new settings. The feeling is a bit similar to that of a downforce car: As long as you keep the tyres within the grip zone, the car feels very planted, but when you go just slightly over the limit, you spin very quickly.

But maybe I just drove a bit sloppy and the higher camber is 100% faster? Not sure what to make of this yet. Also I need to try that same adjustment on other cars to see if they show the same behaviour.

oops I wrote at the same time

Attached Files

•  ALK_GH2_mgc_Qt2t.rar   43.82K   3 downloads
•  Monza_12690.jpg   475.82K   17 downloads

[Millennium]

Interesting stuff, worth some more investigation!

I don't know if my usual method is the right one. But for camber settings I keep adjusting untill the three temperature measurments on every tyre are as even as possible during a race session.
All of my setups are pretty much a-symetric already because of that. But I don't remember having extreme camber ~2 degrees or more ever.

Maybe I've been doing it wrong all this time?

Edited by Millennium, Jan 15 2022 - 08:09 AM.

[Alekhine]

Millennium, on Jan 15 2022 - 08:07 AM, said:

Interesting stuff, worth some more investigation!

I don't know if my usual method is the right one. But for camber settings I keep adjusting untill the three temperature measurments on every tyre are as even as possible during a race session.
All of my setups are pretty much a-symetric already because of that. But I don't remember having extreme camber ~2 degrees or more ever.

Maybe I've been doing it wrong all this time?

hi

For a very long time, pilots have agreed to adjust the camber in order to obtain 1 degree more inside the tire.
That's what I always did until this test yesterday.

EDIT:
There is also, in my opinion, something important, I adjust the cold tire pressures to obtain 166 kpa in front and 180 kpa behind after 4 laps of the track (or after 8 minutes on very long tracks).

Attached Files

•  kpa.jpg   128.4K   26 downloads

Edited by Alekhine, Jan 15 2022 - 08:57 AM.

[Lee200]

GPL models two effects of tire camber on lateral or sideways force.

1.  The tire's lateral force increases in the direction that the tire is tilted.  This is a separate lateral force than is generated by the tire's slip angle.  So even if the tire is pointed straight ahead and has no lateral slip angle, it will still generate lateral force from camber.  GPL models lateral force from both camber and slip angle.

2.  As tire camber increases, eventually a point is reached where the outside edge of the contact patch starts pulling away from the surface.  This decreases the size of the contact patch and reduces lateral grip which decreases lateral force.  GPL models this effect too.

So tire camber produces two opposite effects on lateral force.  It is a complex and dynamic relationship because tire vertical load also affects lateral force from tire camber.  Vertical load is constantly changing depending on whether the car is in a straight line or in a corner.  GPL models this effect too.

Only personal testing will show how much camber is best for your specific car, track, and driving style.

[Alekhine]

Yes, I think that with a classic camber the tire arrives more quickly or more easily on the limit zone which reduces the contact patch, it's maybe because of this "limit-stutter" that I felt instability , especially on very big curve (Curva Grande for example).

Thanx for precisions

[Warren Hall Jr.]

Ah yes, camber thrust. Think of a bicycle leaning into a turn. It's the same for a motorcycle. The more you lean into a turn the more Camber Thrust you get.Just don't over do it .
Warren

Edited by Warren Hall Jr., Jan 16 2022 - 12:56 PM.