amso3

Hi Matt

Thanks for posting. I'd be interested in seeing the "in lap" to see how much the change is in temp and pressure after a hot lap

Jerry

Matt Romanowski

I'll get one up, but the answer is it's variable and car dependant. The Banana loses pressure as the tire cools. I've done this on other cars with hotter brakes and they heat soak and gain pressure. Track temp as drives the tire temp and pressure gain.

Matt Romanowski

I think this is what you wanted to see. This is a little different, but shows what you want. The high spots were after I got out of the car and Judy took it out. Lap time difference was 4-5 seconds.

Matt Romanowski

Here's another really important things you can do with this data - calculate hot tire pressures. I have a small spread sheet that I can input starting temp, starting pressure, and hot air temp to get my hot pressures. I can also start with hot temp, hot pressure, cold temp, and get a starting pressure. This takes a lot of the guesswork out of setting your tire pressures. It's also a pretty big competitive advantage when you have limited time in practice sessions. For a race, where you can't come in to set pressures, it gets you good pressure data from the start.There is still a little bit of art to it, but this makes it much more scientific versus guessing.

boxer-11

I have temperature and pressure data from the OEM TPMS so the spreadsheet is intriguing. I'm not quite clear how it is used though -- it looks like all yellow cells (inputs??) are filled but can it work out the red cell starting air pressure without that value being in the yellow cell?? If you would be willing to share the Excel file I'd like to give it a try and that would save some leg work trying to figure out the math that you've already cracked.