Tire Pressure Tips - what do I need to look for and why?

So

Last time I asked for help the advice helped me to stop spinning like a loon leading me to come second in the Tier 3 race at Imola! Thanks!

People mentioned tire pressure.

I know how to set tire pressure and I am happy to do this BUT how are you meant to know the optimum tire pressure? I mean I have no idea whatsoever. 10 - 99 psi. How are you meant to know.

I notice the Tire ingame app's PSI readout starts blue and becomes green as the pressure increases, sometimes going light green. I take it green is optimum and light green is slightly high pressure?

Is there a rule one should follow to know the tire pressure one should be aiming for?

Thanks!

 

Use Sidekick, it will tell you where the ideal pressures need to be for each tire.

http://www.racedepartment.com/threads/sidekick.123608/

 

If it is green it is good. Don't worry if there are not in the green all the time, pressures vary during a lap (for example at Spa they will tend to go down in the first part of the track and go up in the last high speed sector).

 

If the PSI values are green you are good, if they are red/orange you need to lower, if they are blue you need to raise it. Drive a couple of laps to see where it evens out.

I have noticed on some setups that Ive downloaded from the setupmarket that they using higher pressures than recommended by the app. When trying to lower it to get "optimal" i get worse times. So I guess its also setup dependent but when its all stock it should be best with green.

 

Pressure is key, they need to be green and the need to be balanced, the best app to achieve that is called tire engineer.
Optimum and balance tire pressure will make you faster.

 

But what do you believe is the best way to compromise between pressure and temperature?

 

The best way is optimise and balance pressure forget about temperature.
Follow the instructions in Aris first video.

 

Hmm, that can't be the whole story - if tyres are too cold at optimum pressure and you drop the pressures a little to pull the temps up, that has to be better, no? I just don't know how to balance the two.

 

There other settings that affect tyres temperatures and pressure. A oversteer or understeer car not balanced will raise temperatures more than normal and will affect tyres.

It is a sort of setup that you have to do before and after change other things on car.

Also, your driving style affects tyres too.

 

You do what you think is right, I can only tell you what I have learned and experienced. Keep the pressure optimum and balanced and you will be faster.

 

The general consensus seems to be that you get better performance by having optimum tyre pressures rather than temps.

 

OK, thanks guys. Will experiment a bit to try to get direct proof of what works best.
(I'm an LFS refugee - the general consensus for LFS was that temps were crucial, and the lower the pressure the more grip you had, but the handling was affected of course.)

 

Is it pressure > temp in real life too?

 

Good question! In (current) F1 they usually run the pressures as low as Pirelli will let them for safety reasons, so it seems like lower is just faster, with no obvious pressure value below which you get slower. But F1 isn't exactly the same as other cars...

 

I think some of it comes down to feel as opposed to numbers. We have major spoilage with tyre readouts, where irl, you don't really have that luxury at all times. So finding the right pressures in AC, comes down to numbers and colors, attempting to perfect said numbers and colors. By the end of the day, you may find that simply driving without the readouts will, eventually, give you the answers you seek.
But then again, it's not as easy as real life to "feel" the grip, so a slightly over-pressured tyre may not feel like much of anything (again, slightly). An under-pressured tyre is quite noticeable, especially in the Elise/Exige's.
Give those a try with super low pressures and then high pressures WITHOUT the use of tyre readouts, preferrably with a track that has both slow and high speed corners.

 

Since optimum tyre pressure means optimum contact patch you're at least more likely to have the temps more evenly spread out across the tyre, temps themselves ultimately also depend on driving, car, setup, conditions. That's how you know you're getting close to optimal pressures, checking the temps across the tyre after a few laps.

 

I'll have to give that a shot.

What do you mean by "optimum contact patch"?

 

Over inflate and your tyres balloon so your only running on the centre of the tyre. Under inflate and you're running on the sidewalls.

 

You always have a compromise between temperature (rubber grip) and pressure (pad).
Both to 100% is very rare.

 

Ah yeah, of course. So perhaps F1 tyres are sufficiently compliant that low pressure doesn't make them concave...?