well the tire i'm runnin ( bridgestone re050a's i think) state no more than 40 psi if i read right. i figure 36 is playing safe

 

you should never go by the sidewall of the tire when inflating, that is the maximum pressure for the tire. read the owners manual to get the correct psi, i beleive it is 32

 

That is just bad information. The sidewall gives a maximum air pressure at operating tempatures given a certain weight. Most high performance tires will hax a max of between 42-60 psi at 1600-2000 lbs of load. An S2000 only weighs about 2700 lbs... that is about 675 lbs per tire. So you could easily go to the maximum recommended pressure if that is the case.

I have found that street tires tend to grip and respond better at higher pressures, however ride suffers. AT 32 psi on REO50a's my S2000 feels lethargic. Take it up to about 38-40 psi, and it feels like a sports car.

 

[QUOTE=2poor2mod,Oct 29 2007, 08:54 PM]you should never go by the sidewall of the tire when inflating, that is the maximum pressure for the tire.

 

[QUOTE=2poor2mod,Oct 29 2007, 08:54 PM] you should never go by the sidewall of the tire when inflating, that is the maximum pressure for the tire.

 

 

OK... since no one actually read the entirety of my post, I will spell it out one more time.

The Manufacturer's recomended pressure is just that: a recomendation by the manufacturer based on a compromise between comfort and safety for the OEM tires. It is not a rating to get the maximum life or performance out of your tire.

The sidewall rating is the maximum recomended pressure at a given load rating. If you look, it will say something like "51 psi at 1325 kilos." That is the maximum amount of air that tire can safely handle if it is loaded with 1325 kilos.

An entire S2000 weighs 1300 kilos or so... that means that one tire at the maximum psi could still safely handle an entire S2000... and you have 3 more tires to distribute the load.

The poster whom I was responding to said, "you should go by the door jamb." Thats fine if you are not concerned about performance and are running the original OEM tires ont he original OEM wheels. However, the second you change tires, the rules change; this is because different tires have different sidewall, tread blocks, etc...

Since the OP said he had RE050A's then he isnt running the original tires and the door jamb/owner's manual recomended pressure goes out the window. That is why I said it was bad information.

The moral of the story: Dont be afraid to put more air than "recomended" on the door jamb... It will probably make the car more responsive. Of course, if you would rather blindly follow Honda's legal department, then by all means, air them down... I will wave as I pass you in the twisties.

 

^ I don't disagree with everything you're saying, but I don't think most people will want to pump their tires up to 38psi for daily driving. I had a set of SP9000s on my old Prelude and it had really soft sidewalls, so to compensate I ran 40psi all around. That stiffened the sidewalls, but resulted in the middle of the tread wearing down in about 8-10K miles, instead of lasting 30K as they should've.

32psi is a recommended best compromise for safety, performance and fuel economy. It's the best choice for 9/10 people on the street.

 

True...

perhaps I am being hyperbolistic.

I was mainly refuting the people saying "live by the manufacturer's recomended settings" as though it were the word of God.

Different tires call for different pressures. The mfg recomended pressures are ALWAYS on the low end of the spectrum (for every manufacturer) because they dont want a lawsuit from people flying through a pothole, having a blowout, losing control, and suing for injuries. Additionally they are only for the OEM tire make model and size.

 

I missed that. Could you link to the post where this was said or implied?

As far as optomizing tire pressures for performance, you can't just say that the car works best at a given pressure, because it's not that simple, even with OEM tires. The racing surface (among other things) is a major factor, and to optomize tire pressure and alignment (the two go hand in hand) you have to either measure tire temperatures across the tread, measure grip (skidpad, accelerometers, GPS, etc.), or both. Higher pressure makes the tire stiffer, which makes the car respond qucker, but often at the expense of a compromised contact patch and/or compliance (which is needed more with some surfaces than others).

Where I autocross you'd be sliding all over the place if you start at 36PSI cold in OEM tires. Even hot pressures of 36PSI (again, with OEM tires) are a little above optimal, but it will vary depending on things like temperature and the amount of sand and dust on the surface. No two tracks or courses are ever the same.

It's not that people didn't read your entire post. It's that you calld good information bad information, and then went on a rant. It made it look like you had a serious problem with your reading comprehension.