Tyre pressures you run in your stock NA tyres

[Redondo]

There are so many variables to this and probably should be quoted in tyre size, brand , cold and hot

Even front and back can be different like running 34/38 C/H cold and 35/38 C/H rear

Driving styles, type of driving, when you drive summer winter.

I would run PZeros 38 cold all round on a fun drive but 35 cold for daily.

This could go on and on and on and on and on and on

[93_Clubman]

Racers run higher pressures because they can. Racetracks are smooth. If I go over 28psi on all the B-grade roads around here then I can barely keep the car on the road.

Sure Phil - but that overlooks why they do, i.e. because it gives them better times. We all need to take into account our local conditions & adjust accoridingly, but we're talking generally.

[manga_blue]

The other factor about using street tyres on the track is that you want to get them hot. It's not just a matter of pressure alone - it's the right heat and pressure combined that you seek on the track.

Ideally they should be almost too hot to touch after a couple of laps and the rubber in the tread area will be verging on tacky. Often you'll find ridges of melted rubber on the leading edges of the grooves. There's no way you could resonably get to those sorts of temperatures on public roads.

Most street tyres seem to work best on the track at 37-39 hot, which means yiou start at around 34-35. Almost invariably there'll be very little grip initially because the pressure is too high and the tread is too cold. It's very common for drivers on street tyres to lose control of their cars in the first half of the warm-up lap, even in the section of track between the pit lane and the first corner. (I could give names, places and dates but some things that happen on the track should stay on the track )

[93_Clubman]

All good info Phil which allows people to make an informed decision, but I'm not an advocate of track tyre pressures on the road, although some people are. I'm also not an advocate of slavishly following tyre pressures as per the tyre placard in the belief that they represent the perfect tyre pressure for that car in terms of handling because of a purist &/ or the manufacturer must be right philosophy. As it overlooks the compromises a mass producing manufacturer makes along the journey from initial concept to mass production to satisfy a raft of requirements ranging from national governments to potential buyers.

[manga_blue]

In reality there is no one size fits all for any car or tyre. 28psi works for my car with its suspension and its RE001 tyres. Prior to that it was 31psi for C-Drives. I think it was about 35 for Turanzas. It's 24 cold for my R888s, but they're a different kettle of fish altogether.

What we were always taught was to monitor the wear on all your tyres. Higher wear in the centre indicated overinflation. Wear on the shoulders said underinflation. You would go through a series of fine adjustments until you got even wear right across. At that point you achieved optimum wear rate and also maximum grip.

Many of us do the modern instant equivalent of this at track days with an IR temp sensor.
Immediately at the end of the run you measure temps at inside shoulder, centre and outside shoulder of each tyre and adjust pressures to get the most equal temp readings you can across each tyre, because at that point you get max grip.

[93_Clubman]

You'd be popular standing at the side of the road pointing that thing