(no subject)

[growler_south]

I love having a phone that's also 1/3 computer and 1/3 electric brain. It means that when I come across something I'm curious about, I can either look it up then and there or, if it's not exactly critical, make a note and look it up later.

Why, just today I learned:

-A VW Golf R32 monitors tyre pressures by comparing the rotational speeds of all 4 wheels via the ABS sensors. An underinflated tyre rotates faster due to its reduced operational radius, and the Golf's ABS computer looks for that.

-Fabio, the model, writer and ladies' fantasy novel pinup, was born in 1959, which makes him about 49 this year.

See! The interwotsit *is* useful. Unless you have a real job, in which case it's a timewaster. I consider my life enriched by the above revelations.

Comments

[bratman.livejournal.com]

So now I wanna know how my Infiniti M35 monitors tire pressure.

I noticed that it has to be moving initially, but then I can still get a reading if I'm stopped at a traffic light.

[sinnabor.livejournal.com]

A reading? Does it tell you actual pressures? Neat.

The systems that count ABS ticks can only tell you that one tire doesn't match the rest. They don't give you pressure readings. The more expensive and clever systems have a dingus inside each tire that measures the pressure directly and transmits it via radio.

The cheap systems can't tell you if all *four* tires have been massively over/underinflated by the repair monkeys at your local shop - only whether they match. The expensive ones can.

[bratman.livejournal.com]

Mine provides me a diagram on my in-dash monitor with readings on all four tires.

[goldibehr.livejournal.com]

by comparing the rotational speeds of all 4 wheels via the ABS sensors

That's very clever. And it auto-calibrates too! A friend of ours who runs a repair shop was just complaining about the ridiculous procedure for setting high and low pressure thresholds on some General Motors SUVs.

[dhbearguy.livejournal.com]

I like mine to look up profile photos of various hot men. Like for example, I can quickly look up your photo when I wanna show off a hot New Zealander.

[sinnabor.livejournal.com]

-A VW Golf R32 monitors tyre pressures by

Isn't that how all the cheaper tire pressure monitors work? That's the way the MINI did it. Once you've got an ABS computer sitting there counting wheel revolutions anyway, it's essentially free. Maybe a button, a light, and enough extra CPU power to handle it. I wonder what the algorithm looks like...

[smellykaka.livejournal.com]

So when you're doing burnouts the thing goes "DING DING DING!" and tells you your driving wheels are completely flat?

[growler-south.livejournal.com]

No, because it looks at all 4 wheels at once. And since all 4 wheels would be doing the burnout....

[sinnabor.livejournal.com]

Oooo, AWD + LSD? Teh hawtness.

[mattbear66.livejournal.com]

Fascinating!! Tell us more!

[greatbearmd.livejournal.com]

My MINI has the rotational differential sensing. It's a silly simple system, all that is needed is to average the distance each wheel travels by tallying up the pulses from the ABS sensors, the one with the significantly higher count is the low tire. It's not infallible though, if all the tires are low by the same amount - like what happens in the winter or if all the tires have a slow leak, the system is blissfully unaware of it. My new truck actually has a sensor in each wheel that measures pressure directly and reports it on a display in the dash, if any of the pressures read out of limits, the warning will be sounded for a particular tire position along with the pressure (or lack thereof).

Direct-reading system are becoming law in the US, mainly as a fallout to all those Ford Explorer SUVs that were blowing apart their Firestone tires and rolling over. Rotation-delta systems were a stopgap until the real stuff gets migrated into the various models.