Airspeed indicator for your car

[SVOboy]

W00t, you're one crazy fool, y0. I hope you learn something with it and I might have something else to put on the list of things I wish I had. My vacuum gauge and a pound of swedish coffee are in the mail right now (from sweden), can't wait to get it installed.

[krousdb]

Originally Posted by SVOboy

W00t, you're one crazy fool, y0. I hope you learn something with it and I might have something else to put on the list of things I wish I had. My vacuum gauge and a pound of swedish coffee are in the mail right now (from sweden), can't wait to get it installed.

Not so crazy. It is in my tinkering budget, which comes from selling stuff on ebay. Anymore when we buy something I keep the packaging for resale on ebay. If I like it keep it if not it goes on ebay. The latest example is one of those indoor invisible fences for dogs. The first time out the pup got zapped, she has never gone in that room since, about 2 months. So i am about to sell a very slightly used invisible fence. I usually get about 2/3 of what I originally paid. It's amazing how much crap you can find laying around the house to sell.

Anyway, if I decide not to keep it, I know who might want it. Maybe a trade for transmission installation services. Oh yea, and I have a digital fuel gauge that I no longer need (SuperMID instead).

[SVOboy]

I still need to get that ish picked up, if my fuel rail ain't on my doorstep today (or in the mailbox) I'm taking the camry up to visit that guy to get some free stuff, *sigh*

[krousdb]

The 0-80 Ait Speed Indicator showed up today. It consists of a gauge, clear tubing and a hollow alimunim rod the size of a pencil. The hose connects to one end of the rod and the other end of the rod is to be mounted on the car with the opening facing forward. The other end of the tube connects to the gauge. When you blow into the end of the rod, voila, the gauge moves. Evidently I am quite a blow hard because it can easily peg it at 80 MPH.

The gauge came with a calibration test report. it was tested in 10 MPH increments from 20 - 80 MPH. The calibration is within +/- 1 MPH at all speeds.

So now you know what I will be doing this weekend. Anybody have any ideas where to mount the intake tube? It needs to be somewhere that will get the full force of the wind, but without much turbulence. I am thinking that I will mount it in my grille block, sticking out as far forward as possible. Whadda you think?

[kickflipjr]

Awesome. So it works. I might want to get one.

[MetroMPG]

sounds cool...

Originally Posted by krousdb

I am thinking that I will mount it in my grille block, sticking out as far forward as possible. Whadda you think?

methinks that sounds reasonable.

plus, you can use it to poke annoying pedestrians at crosswalks. but be careful: if you hit a bug with it at just the right speed, will it get blown through the tube and pop out inside the gauge?

please report back with the mpg insights you will glean from the wind-o-meter and how it helps refine your technique.

[philmcneal]

damn for 20 dollars that can't be beat... actually ill stick with putting a canadian flag up front or something since it requires some installation and I'm the "plug and play" type of guy.

[rh77]

All commerical aircraft have what's called a "Pitot Tube" that measures indicated airspeed. You may have seen it on some aircraft "Do not touch, Hot", it's generally on the Pilot's side by the pax loading door -- looks like a copper tube sticking out the side. That's the secret, it heats up to measure the number of air molecules that pass through at a constant temperature -- as we know the upper atomosphere gets cold -- as does PA, right? An aircraft supply store might be able to provide a used tube and guage. The only thing, it needs to be mounted entirely in the stream of air -- no hiding in the grille. I honestly can't think of a spot to mount it, without it looking like it doesn't belong on a car. Maybe it can be mounted on the roof a-la XM antenna style. At any rate, that will get you the most accurate airspeed without compromise. Sorry, kind of into airplanes as well as gassavers. What, a guy can't have two hobbies?

RH77

*Edit* Maybe I should read the whole thread. One has been bought already. Okay. You need to mount it similarly to what was mentioned - in the stream of air. The outlet on the other end may not work well venting into the grille. It needs to be completely in the flow of air - in and out. I know it won't look fantastic, but maybe under a side-mirror. Better yet, under the car -- air flows under there at nearly the same speed as up front or on top/side. If you bottom out, though, it's toast. Maybe even the rear of the car under the bumper. Unrestricted airflow is the key, or it's bunk.

[krousdb]

This one is different than the aircraft one because it is really just a diaphragm that deflects with pressure from air flow via a tube from outside the car to the gauge inside. In the back of the gauge is a hole that serves as a static pressure reference. The manufacturer refers to it as a pitot tube but technically it is not.

A true pitot tube (by the way, I used to work for the company that invented the pitot tube, Pitometer Associates was the name)measures the pressure of the air as it is forced into the forward mounted orifice and also measures the negative pressure with a reverse mounted orifice as the air goes by. It then adds the two together to give you a reading.

Anyway this one should work fine as a rod sticking forward out of my grille because I don't need the outlet that you speak of. The outlet is inside of the car and is supposed to measure static pressure so it shouldn't be subject to any airflow.

I do have an XM antenna but had to mount it on the trunklid. My removeable roof is alumunum and the magnetic antenna doesn't stick so well.

Phil,
This Airspeed gauge was not the $20 one, it is $134. I will never see a return on investment but at least I will have a lot of fun with it.

[krousdb]

OK, its installed. The tube is on the drivers side just under the air dam extending 3" in fromt of the bumper. There was already a hole in the bottom of the air dam and something to lever the rod against to hold it in place.

The gauge mounting was too easy. I have circular vents in the dash near each front window. I popped out the vent on the drivers side and popped in the gauge. It's a good press fit so no fastening required, I will try to take some pics after a thorough testing.