Fat 911 T4 Cooling .. datalogger results

[Sandeep]

I'm converting to a thermocouple for oil temp because the IC's I use to read the TC's have an error of 0.5 F and their output is linear. No need to calculate or extrapolate the temp from graphs that are provided for a particular thermistor, whose output in not linear with temp.

For AAT and FIT, I'm also using IC's with a linear output but the IC tells the temp accurate to 0.5 F, no TC's here and the IC is the size of a pencil eraser ... very small. FIT and AAT won't get above 50 C and the IC's are very accurate in this range.

The auto-max gauge concept is for me to tell if the heads are too hot when I am racing ... I can always tell which cylinder was too hot when I look at the graphs after the run.

I could have used an LCD on the dash to give me the required information, but I like the look of the gauges ... and I don't want my dash to look high-tech ... I want it to look like VW could have built it in '74

Sandeep

[Massive Type IV]

Sandeep,
Head temps are normally not a huge concern in road racing except on the straights.

In the infield you are working in the upper RPM and in a lower gear which removes load from the engine..

Your datalogger will show this very well..

[Bill K.]

Sandeep, are you sticking with a 1 Hz sample rate? How did you decide what was enough but not too much data?

[Chris Percival]

Cool charts.. Whats the 'FIT' measurement?

[Bill K.]

Originally Posted by Chris Percival

Cool charts.. Whats the 'FIT' measurement?

Fan Inlet Temperature

[Sandeep]

While playing with this datalogger, I've got some cool graphs and I've got the RPM sensor working now. Just have the Rear Wheel Speed sensor to make up to have it fully operational.

I was taking 1 sample per second to see if the programming worked (it did) but have now changed the code to take 1000 samples of each channel per second, taking the average value to get an accurate value to store.

This is limited by the registors in the microcontroller as to how large a value I can get before I divide by 1000. I used 500F as the value to decide this ... hopefully the heads will never reach 500F

Sandeep

[Supa Ninja]

Wow this a awesome thread. Since I'm going to use the FAT setup, already got my fan and ring back from the powdercoater (I told you Zen I'm going to bite off your old setup). All I need is the shroud. I also dig the techno stuff a lot too. The data logger you setup Sandeep sounds very cool. Are you going to write up a tech article on how to make your own?

Nick