PSS/PS4S Track PSI help

[M3MATT]

I’m looking to get a rough number of what E9X guys run on our cars for track use on Stock PSS tire sizing (or ps4s since it’s close enough)

I’ve seen as low as 32, and as high as 45. Most seem to be between 34-38.

My cars fully solid/spherical, Coilovers, track alignment, sway bars, and roll center correction for some context.

[amg6975]

I have nothing helpful other than that's a lot of mods to be running Super Sports. Even an enduro 200TW is going to be better at everything than the PSS, and last longer.

[omgzirra_exe]

Originally Posted by amg6975

I have nothing helpful other than that's a lot of mods to be running Super Sports. Even an enduro 200TW is going to be better at everything than the PSS, and last longer.

Yeah, nothing to say here because of that. The limiting factor is the PSS... if you're running track alignment, which I'm assuming is around -3F/-2.5R, 0 Toe Front, and some toe-in rear... you're going to destroy these, lol.

From my experience, your "end of session" target pressure should be 40 to 42 then bleed down from there based on your feedback from that session.

so if you use the average rise in pressure to be up to 6psi you'd start around 34- 36 cold (using 40 end of session target pressure)

Then buy new tires, because they are going to rip apart same day.

[1FastSicilian]

Matt, you already know what I'm going to tell you.. lol you need some 200s!! haha

[Estoril Blue]

I haven't run them - but I advise my students running them to max at 38 psi hot. The real answer is to buy or borrow a probe-type (not IR) tire pyrometer. Then measure temps across the face of the tire.

That will tell you your specific target and you can manage specifically with facts and not some pressure from someone else's car on a different track (and track surface) in some unspecified ambient temperature and season.

Longacre makes a good product that I have used for years.

[M3MATT]

Originally Posted by 1FastSicilian

Matt, you already know what I'm going to tell you.. lol you need some 200s!! haha

200TW’s are calling my name through you 😂

[Cmassey3]

I recently came back from VIR and started our warm day on 30PSI cold all round and never got it above 35. Was hoping for 36-38, but did not end up getting that heat in the tire.

For our rain day, I went with factory pressure 33/35 cold and left it even up to our last session which was full dry and the car did great. Granted, this is on factory alignment with EDC.

[MineralWhiteF80]

it's hard to recommend a specific tire pressure for you because of many factors for your car, driving aggression, and track layout, but I WILL say that PSS and PS4S have relatively soft sidewalls compared to popular 200TW tires. With that said, PSS and PS4S need a little higher starting tire pressure because the sidewall tends to roll over easier and cause accelerated outside wear before they get up to temp.

The last time I drove PS4S in the dry, I noticed an 8 psi increase at the end of a session. I originally started out at 30psi and noticed the outside shoulder wearing past the tread down into the sidewall. That was due to the pressure being too low and me driving it too hard. I eventually ended up finding 32-33 psi cold and 40psi hot seemed to get the best wear for my setup (3600lb car/-3.0F/-2.0R camber).

The thing to also take away is that the PSS and PS4S can be a great track tire, you just have to drive within the limits of that compound. You cant beat on it every lap and expect it to survive like a 200tw or lower track tire. As long as you treat them right, the tires should survive fine- you just cant abuse them and then get mad afterwards.