Temps and Pressures

[Deleted member 387850]

After Sunday's GT3 @ Spa event I've been struggling to get my head around tyre temperatures and pressures in AC. I've read some of the setup guides on RD but I still can't seem to find a balance between tyre temps and pressures.

I've been running the BMW Z4 GT3 with medium tyres for race setup and 21c air temperature at Spa. If I set front pressure to 18psi and rear to 19psi I get a fairly consistent 26psi (+/- 1) which reads green. However, the tyre temperatures remain blue for at least half the lap, especially sector 1.

Is this normal for a track like Spa? Given the long lap and long straights perhaps I'm expecting too much for the tyres to remain at the optimum temperature for the whole lap? For example, from Courbe Paul Frere all the way to Les Combes it's largely all 6th gear with the exception of the chicane and La Source, so I guess it's inevitable the tyres will cool. From Les Combes on the temps start to come up and stay there until after Stavelot when they start to drop off again.

If I lower the tyre pressures I can generate more heat, but then the pressures read blue. My experience to date is that I have more grip running optimum pressures with cool tyres than optimum temperatures with low pressures.

My lap times on the mediums are low 2:21's so perhaps I just need to drive faster

 

[Kek700]

Yes. you make a choice, softs "good" for 2/3rd at the race at a workable temperature
,then hang on for the next 1/3 of the race or mediums which run to cool but are reasonable
for the whole race.
I try for exact recommended pressures as I cross the start finish line.
With the softs on the gtr gt3 26psi on all corners, as I pass the start finish line.
There are some technics for increasing the tyre temperature, but I prefer to
concentrate on the correct pressures and getting the car to work nicely around the
whole circuit. when I have focused on tyre temperatures it has never been successful
on a track with a low temperature.

 

[NicoB79]

Sector 1 in Spa is nearly only straight so the tires cool down which results in lower pressure. When the pressures read green for the rest of the lap I think you are fine.

 

[Brandon Wright]

My experience to date is that I have more grip running optimum pressures with cool tyres than optimum temperatures with low pressures.

That's pretty much been my experience in AC. I can almost never get tires up to what would be considered a proper temperature. Eventually I just stopped worrying about temps and focused on pressures and once I got my pressures right everything felt great, now I never even look at temps. That's probably not the right way to approach it but I've have a much better experience since I started paying attention to pressures and ignoring temps.

 

[Deleted member 387850]

Thank you all for the replies, it seems to back up what I've experienced so far so that'll prevent me spending an untold amount of time chasing unrealistic tyre temps! I'd also tried to experiment with things like increasing negative camber to raise tyre temps, but it seemed to only really affect the temp on the inside of the tyre and didn't seem to raise the core temp much, if at all. And obviously if you go too extreme it can have a serious affect on the balance of the car!

 

[Matheus Machado]

You can try changins suspension so it takes more load into the tyres.

But I never had issues since tyre model V7 with cold tires in AC. Maybe you were not pushing the tyres to the limit?

 

[Deleted member 387850]

Maybe you were not pushing the tyres to the limit?

That is almost certainly part of it! The classic conundrum - need heat in the tyres to drive fast, need to drive fast to get heat in the tyres

I'm a recent convert to AC and I've heard people talking about the change to the tyre model, but I've only experienced the "new" tyre model.

 

[Kek700]

2:21 for Spa is good, it is just a problem with Spa and tyre temperature. That is why I go for softs at spa.
I am not saying it's fastest over the whole race distance. It just makes the first 2/3rds of the race easier.
Buy the time you get to the last 1/3rd , the race is almost cooked by then anyway.
That does not apply to say the Porsche, which will almost completely cook its rear Tyres by the end
of the race if you use Softs. "I am talking about the racedepartment's 45 minute Gt3 events".

 

[Rob Every]

In a Z4, 2.21 is fair to be honest. If you can do it all the time in traffic, and over 45 mins pretty good. You will find people in publics doing 2.18 routinely. And I have seen guys that can race 15's routinely over 10 laps somehow in other cars. They can all take Eau Rouge flat and set the car up for that over everything. I would say that yes a soft will last, but will be ragged by the end. And in a Z4 you are likely using TC and ABS, whereas in some cars you can get away with not running them.

I find outside temp makes the biggest difference to how your tyres work, over pressures.

At say Brands or Mugello or Zandvoort I have to run higher pressures on mediums even in short races in hot weather, as even in 10 lap races softs will just get too hot coz of all the right handers. So you are over inflating the tyre and it seems to work better, seems odd, but it has worked for me!! Probably because it is simply getting so much work I have picked the perfect pressure.

But I find softs are fine at Spa, have even run supersofts in the M3 in cooler weather and they lasted just on 8 laps. But burn out in longer corners.

I have the tyre temp readout on screen all the time and find it fascinating how the outside weather affects tyres. But Spa is fairly equal and long so your tyres can cool.

Also, according to some people, cambers don't make a huge difference. Not sure why, but they don't.

What you will find with this game, as any, is that some drivers will have experimented a lot and found out what changes to setup make the biggest difference, it might be bump and rebound on some sims, camber on others, diff settings on others, ride heights on others. I played an Rfactor short oval mod years ago, and stagger did not work at all, yet cambers made an enormous difference. To extremes and in ways that real cars never work.

The aliens know, and the rest of us don't. As I say all the time in servers, they are playing a different game to everyone else as they know exactly what tweaks work to exploit the game physics, not necessarily ones that work in real life.

 

[Kek700]

Absolutly agree, exploiting a simulator is not the same as real life, real life will just not
accept driving that a simulator will, and that includes setup's.
It just, in my opinion, is a very good simulation, both visually and practically.