pitot tubes on race cars

[Cody Forbes]

> Out of curiosity, anyone know why a number of the prototype ALMS cars
> sported pitot tubes?  I've seen the same thing on pictures of F1 cars.
>
> Sorta visible here if you click on the image for the larger version:
> http://frank.mercea.net/zoph/photo.php?album_id=20&_off=8
>
> (right in front of the headrest hump)
>
> Oh, and much better visibility here:
> http://frank.mercea.net/photos/cars/CRW_4399.jpg
>
>
> Generally in aircraft they provide:
> -speed indication
> -vacuum (or pressure) for driving the gyros in an emergency
>
> Neither seems terribly useful in a racecar with four perfectly good
> wheels to measure speed from(and an accelerometer to tell when
> there's wheelslip, for example).  If you need an artificial horizon
> gyro in a racecar, you're doing something wrong :-)
>
> Only other thing I can think of is for measuring aerodynamics, but
> would one fixed point be all that useful?  Maybe a reference pressure
> for other ports along the car?(if so, they're well hidden!)
>
> So I give up.  What's it for?  Google turned up nothing useful.
>
> Brett
> -- 

Possibly for aero like you mentioned, but maybe not for aero on the car it's
installed on, maybe for measuring pressure drop when behind other high
downforce cars. Could be used to prevent becomming a Mercad---- er ah I mean
aeroplane at Le Mans. A bit far fetched I know, but it's the best thing I
can come up with. Another possibility is speed measurement, which you
discount because of having wheels to measure from, but remember those
sensors would add unsprung weight.

-Cody Forbes
http://www.500tq.com