Using TPMS system to check pressure and temp on track

[jdherman]

Has anyone used the built-in tire pressure and temperature display in iDrive to check PSI and temps while on the track?

I'm curious to see if folks think the system is accurate enough to give good track feedback to help dial in proper pressures for HPDE or open lapping events.

I thought that instead of trying to read hot pressures immediately after leaving the track, why not just glance at the display as you start your cool down lap.

Thanks.

[Reach]

It's off by a few PSI. I'm also not sure how often it samples. I checked it coming off track and then with a dial gauge in the paddock. Dial gauge read higher, so it wasn't just the natural cooling effect of time.

[YMB_M3]

Mine is not very accurate, I always have significant discrepancies between the tpms and dial gauge reading

[joebloggs1000]

Mine are the same, couple of PSI lower than the hand gauge.

[jdherman]

Thanks for the replies. I'll stick with measuring with a gauge.

[robbo mcs]

It is still very useful. Gives you an idea when cold tyres are getting up to temperature and pressure. Also if you see the pressure go much too high or stay too low, time to come in and adjust.

However, as others say, not accurate enough to fine tune by.

[afadeev]

Originally Posted by robbo mcs

It is still very useful. Gives you an idea when cold tyres are getting up to temperature and pressure. Also if you see the pressure go much too high or stay too low, time to come in and adjust.

However, as others say, not accurate enough to fine tune by.

Actually, mine a very consistent across all four corners (within 0.5 psi of actual, erring on the high side). Once I set the hot pressures to 35psi all around, the TPMS sensors read between 35.4 and 35.6 on all four corners. Consistently.

On track, I subtract 0.5 psi from indicated, and decide if it's worth breaking out the proper pressure gauge to adjust the pressure.

TPMS is less useful for temp readings as you care about the temperatures across the surface of the contact patch (outer, mid, inner), not the air inside the carcass. Which is what the TPMS is measuring.

YMMV,
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