Lately, I´ve been setting up the tyre pressure based on the following: 1. I see every car is set a 177 psi (at least in the GT4 category I´m running now), which I assume is the ideal pressure. 2. Go for a run and check the pressures, if some tyre exceeds from 177, get back to the box, and lower pressure there. 3. If some tyre doesn´t get 177 on the run, do the same, but raising the pressure. 4. Eventually, there will come a sweetspot where all the tyres stays in 177 overall, so I stop setting up pressures at that moment. 5. The next step would be setting up the camber so they heat up evenly inside/outside, but that´s not a step I need to discuss. Personally I´ve found that the tyres degrade way more even between the four, they last longer and almost always stay in green. What do you think of this? Am I wrong?
No, it generally doesn't work like that. 1) Our goal is not some built-in predefined number for pressures, but a good temperature spread, that is when middle temp equals the average of outer and inner temps - only that would ensure the best contact with the road. My test showed that when tyre temps move away from their best working range, pressures will also move away from what you see by default on the setup page. These are temps and pressures after 8-lap stint. This car has 175 front/178 rear pressures by default. See how only two tyres are close to these numbers, the other two are off despite a pretty uniform spread. If you set them all up to match 175/178 you lose a bit of grip on these wheels. 2) I see you weren't going to discuss the last step, but it's also incorrect. You shouldn't aim at equal inner/outer temps, there should still be some difference between them. How big, depends on a car and track. If I recall correctly, it's something about 10 degrees for the likes of GT3/GT4, 5 degrees for classic cars (I assume those with cross-ply tyres) and 15 degrees on the fronts for modern-era touring (FWD) cars. (Upd: link: https://forum.sector3studios.com/index.php?threads/adjusting-tyre-pressures.16575/#post-230954)
This is a second time I see someone using this method. Does it have something to do with ACC? I feel that that game inadvertently created this idea that there exist some universal ideal pressures and you need to aim at them.
No, it´s not ACC related at all. It was a thought I had and wanted to test it. I know about temps and stuff, but all I can tell you is that I notice the difference. And the benefit in the long run is huge. Just give it a try and do a long stint with that method.
Not sure I have that much time to spend on tests, but maybe... Either way I trust what Alex Hodgkinson says about setting up pressures, it sounds reasonable. Your method takes as much time as his, but also requires learning the "ideal" pressures from some external source. Default setups aren't a source for anything, they are just safe baseline setups made in such a way that you could jump in a car and be relatively fine in terms of handling and performance.
As already pointed out, this is not the correct method and won't get you good results. This is how it should be done. I can safely say there's not any alternative approach which will work. I think you've stumbled across an alternative way of making sure tyre pressures remain consistent across a long run which is a good thing. However they may be consistent but they won't be optimal. The most important thing to check when fiddling with setup is the stopwatch. The end goal is always faster lap times, so your sanity test should always be to keep referring back to lap times.
Thanks for the extra info, but... why not aiming to equalize inside/outside temps by using camber? That would mean the contact patch of the tyre is being used efficiently all across. I use camber all the time to do that, then I adjust pressure to make the central part equal to the other parts as much as I can (when I don´t use this pressure method)
If you equalise the inside and outside tyre temperatures over a lap, then you're over using the outside edge of the tyre in turns. Imagine you're looking at a car from the front. As it starts to take a turn, the body rolls towards the outside of the corner. That has the effect of laying the outside tyres down flat against the road, which is basically what we want and what we use camber to optimise. We still want some camber on the outside tyres because they produce more lateral grip under those conditions. The inside tyres now of course have more camber than on the straight, but they're not the ones bearing most of the load so it's irrelevant. It's because of the way we have to set up camber this way that we always want/have hotter inside tyre temps. This is because the tyre is running on it's inside edge on the straights. That is not necessarily a bad thing as it helps to retain overall heat as well as slightly reducing rolling resistance. Not what we want:
Ok, that makes sense and I will absolutely check it, but my doubt still stands: The camber is adjustable, so how to know how much camber do I need for a setup? If I understand well, you don´t touch camber, although you can. That means there´s an ideal camber value for a given car/track/driving style combo. In the past, I´ve learned we need to equalize inside/outside by using camber. How do you personally handle camber values then? There must be something to be gained by setting up that, right?
More camber is usually better when cornering since you can carry higher g-loads, but there's a certain "budget" for tyre heating and wear on the inside of the tyres. For non-driven (front) tyres there should be no more than 10-15 C difference between the inner and outer edge, while for the driven (rear) tyres it should be less, typically a 0-5 C difference, because otherwise grip under acceleration is compromised too much. If I am below these limits, I will increase cambers until I reach the limit. If I am above the limit and the tyres are overheating or the car feels skittish under power/braking, I will reduce cambers.
So, I´ve tested Alex method vs my method and came to the conclussion that you get the same results. Once a couple of laps passes and the tyres temps get stabilized, I get exactly the same results with both methods, inside/outside more or less equal and center temps in some value in-between. The only difference is in more extreme cases, where I need to put really low or high pressure in one tyre, it heats up in an ugly way, but once you let some laps pass, it also get a smooth homogeneous temp reading all across.
What track and car did you use? I mean if a track has more or less equal load on right and left tyres it's one case, a track which loads mostly one side is another.
What you want is to minimise temperature gradient (inside/outside temp difference) across the tyre surface while cornering. Although a little bit of gain is preferable. What that means is you need to get into using 3rd party data logging software to monitor tyre IMO temperatures. There's no other way to do it, and it's something where you need to be able to look at the big picture as every corner will effectively be a compromise. What works in hairpins won't work be good for fast sweepers, for example.
That´s correct, I want to set the tyres for cornering, I always check the tyres when exiting the corners, not in the straights, but using my method I don´t need to check temps, I check pressure (pressure and temperature is directly proportional, one goes with the other one hand in hand, so more pressure means hotter tyres and viceversa), I don´t need 3rd party apps to check anything.
Anyways, I see someone voted "I tested it and it works". It could be nice if he/she could drop some thoughts here about his/her test.