Data Recorder

[ClayGlover]

Any feedback on this tool? Capabilities include EGT, RPM, speed, dual axis acceleration/turn g-force, head temp, etc....

http://www.eagletreesystems.com/BoatDataRe...ProductInfo.htm

 

[Mark]

Seems real cheap but give me a couple of weeks and i'll buy one. Data loggers make you go so much faster but take a while to get the most from. Some friends of mine use them on full size race cars. I don't know why but they spent like AUS$6000-$8000.

 

[lohring]

We are testing the Eagletree prototype boat version on a K&B powered modified tunnel. It reads servo positions, airspeed, temperature, and rpm. The airspeed seems a little high on our instalation, but we haven't checked it against a radar gun. It was very interesting to look at the rpm data. Though peak rpm and speed data has long been available, data from the turns has not. From the very short testing we have done we found a significant variation between two different pipes. It should be invaluable for propeller testing around a course.

Lohring Miller

 

[[email protected]]

Lohring,

What do these sell for??

 

[ClayGlover]

Lohring,

How long is the pitot tube, can you adjust the length of tube? How close does the rpm sensor have to be to the flywheel magnets? would it get in the way of an inboard's starting belt? ah, now that I think of it, just put the sensor to the engine side of the flywheel. at $160 for the recorder, temp sensor, rpm sensor, and software, it seems a great deal if it works consistently. very interesting stuff

 

[DaveMarles]

Lohring,

I'm going to get one of those gadgets but the temperature reading isn't good according to their data. It shows that it reads up to 420F and even on a .90 nitro boat I see over 550F and on a gas boat its way higher than that. Thats measured at the centre of the fat part of the pipe.

Dave

 

[Bart Drieghe]

Dave , are they measuring the Pipe or are they measuring the head of the engine ?

i thought it was the head of the engine ?

regards ,

Bart

 

[ClayGlover]

I found this under the "EGT Expander Instruction Manual"-

"The EGT Expander works with your Data Recorder to measure up to two channels of EGT. It uses a K type Thermocouple mounted in the exhaust stream for this purpose. Since two channels are supported, one channel can be used for EGT, and the other for Cylinder Head Temperature with a small ring that fits under your glow/spark plug. Email us for additional probes.

EGT Expander Specifications

Channels: Dual

Max Temperature: 2000+ degrees F. Software will calibrate to around 1800 degrees C, but this has not been tested.

Weight: approximately 0.8 ounces with Expander board, probe and fitting."

The 424F must be the head temp max? Probably a different type of thermocouple/thermistor to give more accurate readings within that lower temp range?

 

[Ian Inverarity]

That looks very interesting, I might have to invest in one! B)

But a proper course and stop watch is also a very good way of monitoring perfomance.

Such data recording could provide some very interesting and useful information. Now for the pit crew to analyse the data...

Ian.

 

[Bart Drieghe]

i got the same thinking .Do you think its necessary to have the temp of the exhaust to ?

Reason ?

regards ,

Bart

 

[DaveMarles]

Bart, I use onboard tacho, occasionally rpm telemetry, GPS, radar gun, and still I want to go faster with the .21.

Dave

 

[Bart Drieghe]

yay lol im getting close lol i got onboard tacho and gps lol ( wich is pretty unknown in Belgium )

and im using servo's lol and a receiver too lmao

now serious , do you think its really necessairely to know what the exhaust temp is dave ? I had in mind to buy me an infrared temp thingy , just to measure the headtemp , never had in mind to measure the exhaust temp.

 

[DaveMarles]

I want on the water EGT measurement for my tuned pipe work.

Dave

 

[DaveMarles]

And then we need access to the Peugeot windtunnel like certain French guys have ...

 

[Ian Inverarity]

Is that a moving ground plane wind tunnel.... B)

Nitrocrazed racing: Just for fun.

 

[lohring]

We glued the magnet into a slot in the bottom of the flywheel with the very small pickup under the flywheel. This let the standard outboard starter work normally. The temperature sensor we have was designed to measure cylinder head temperature. I'm not sure about exhaust gas temperature sensors. The airspeed pickup has a tube for dynamic pressure, but the static pressure pickup seems to be internal. This could lead to sensing errors, especially if the unit is in a sealed radio box.

Our testing is very preliminary since we are trying to get ready for the Legg Lake straight-a-way runs at the end of the month. We hope to have two units in boats for more tests soon.

Lohring Miller

 

[Mark]

As long as you did all of your speed testing and data logging with the one system it shouldn't matter if the air speed pick-up was not dead accurate in relation to miles or kilometres per hour because if it was out say 8 mph at 100 mph then it will be 8 mph out tomorrow as well so if you tried a different prop then you would be able to measure a difference in speed.

It should only be a concern if you didn't have a consistant reading from one run to the next providing you didn't make a change to the boat. Oh, of course you also couldn't go bragging that your boat does this speed or that speed.

 

[lohring]

Actually the true speed is important for propeller testing. I have been surprised at the amount of slip. Knowing the slip tells you the angle of the blade element to the flow. As long as the airspeed readings are consistant, they can be calibrated against a radar gun or time through a measured course.

Lohring Miller

 

[Mark]

Good thinking lohring and good solution to an important problem.

 

[Tom v.d Brink]

Hi lohring

could you give me a slightly more detailed view of the slot you glued the

magnet in.

also what glue did you use and did it stay in place?

I remember i once glued the sensor for one of those tachs in with epoxy but lost the magnet first run out <_<

also how did seal up the wires from the radio box.

thanks for the help

Tom