What is the probe/sensor in rear diffuser? - The Unofficial BMW M5 Messageboard (m5board.com)

Digi · 16th July 2006, 16:00

There is a probe/sensor in the left front brake duct that I assume is the temperature sensor. What is the probe/sensor in the rear bumper duct / diffuser?

SWP · 17th July 2006, 19:56

I was wondering the same thing.

I am not sure the probe/sensor in the left front brake duct is the temp sensor. It would seem strange to have a temp sensor in a location where wind will blow at it directly at 100 mph.

Digi · 17th July 2006, 22:14

Quote:

Originally Posted by SWP

I was wondering the same thing.

I am not sure the probe/sensor in the left front brake duct is the temp sensor. It would seem strange to have a temp sensor in a location where wind will blow at it directly at 100 mph.

There is no change in temperature because of the effect of wind on non-living objects at the same temperature as the surrounding air. If the temperature probe said the temperature was 32 degrees, and the wind speed changed from 0 MPH to 100 MPH, the temperature probe would still indicate 32 degrees. An object that creates its own heat will lose heat faster as the wind blows faster, but it still won't cool beyond the ambient temperature of the air around it.

SWP · 17th July 2006, 23:22

We know who is a scientist here, and who is not. Thanks.

But won't wind chill play a part?

Oops. You answered this one too! Never mind.

Quote:

Originally Posted by Digi

There is no change in temperature because of the effect of wind on non-living objects at the same temperature as the surrounding air. If the temperature probe said the temperature was 32 degrees, and the wind speed changed from 0 MPH to 100 MPH, the temperature probe would still indicate 32 degrees. An object that creates its own heat will lose heat faster as the wind blows faster, but it still won't cool beyond the ambient temperature of the air around it.

canysmc · 18th July 2006, 00:56

Is this it?
http://www.realoem.com/bmw/showparts...00&hg=61&fg=25

SWP · 18th July 2006, 01:02

Question about RealOEM. Who are these guys? Are they reliable? Has anyone had problems purchasing from them?

vicinolf · 18th July 2006, 07:20

Certainly there must be one jet quaified pilot driving around in an M5. And if there is he will tell you that indeed Ram air temperature (RAT) does exist and will heat up any body traveling through the air. An M5 cruising at say 195 mph will create a ram rise of about 5 degrees F. Ceramic re-entry tiles aren't really necessary but they might look very cool. No pun inteneded

Quote DIGI

Quote:

Originally Posted by Digi

There is no change in temperature because of the effect of wind on non-living objects at the same temperature as the surrounding air. If the temperature probe said the temperature was 32 degrees, and the wind speed changed from 0 MPH to 100 MPH, the temperature probe would still indicate 32 degrees. An object that creates its own heat will lose heat faster as the wind blows faster, but it still won't cool beyond the ambient temperature of the air around it.

Digi · 19th July 2006, 03:21

Quote:

Originally Posted by vicinolf

Certainly there must be one jet quaified pilot driving around in an M5. And if there is he will tell you that indeed Ram air temperature (RAT) does exist and will heat up any body traveling through the air. An M5 cruising at say 195 mph will create a ram rise of about 5 degrees F. Ceramic re-entry tiles aren't really necessary but they might look very cool. No pun inteneded

Quote DIGI

OK, I give on that one...yes the temperature probe may be affected at supersonic speeds.

drewzMMM · 19th July 2006, 06:25

Quote:

Originally Posted by SWP

Question about RealOEM. Who are these guys? Are they reliable? Has anyone had problems purchasing from them?

They are very reliable and professional.

They shipped my stuff out ASAP and gave me a great deal.

vicinolf · 19th July 2006, 07:46

Quote:

Originally Posted by Digi

OK, I give on that one...yes the temperature probe may be affected at supersonic speeds.

Not MAY, but WILL...and, not just supersonic speed but any speed.

You're officially off the hook.

Happy Motoring

Digi · 19th July 2006, 13:25

Quote:

Originally Posted by vicinolf

Not MAY, but WILL...and, not just supersonic speed but any speed.

You're officially off the hook.

Happy Motoring

An engine block in 32 degree weather that has cooled to 32 degrees remains at 32 degrees whether the wind is 0MPH or continuously at 100MPH. It is really good not to have to consider the effects of wind chill when determining the amount of anti-freeze to add, as wind chill has no effect on the temperature of the engine block or the temperature probe.

The air at the temperature probe is hopefully not being compressed enough to heat it up. I think the heating effect of the nearby asphalt pavement would have much more effect on the probe than any ram air effect at "normal" speeds.