Fat 911 T4 Cooling .. datalogger results

[Sandeep]

I've just completed my datalogger and here are the results of the first run. I was driving quite hard but only for short bursts .. see #2 below.

Time in seconds is on the x-axis, and the sensor data is on the y-axis, logorithmic scale so I can show all data on the same graph.

Some notes:

1. The engine warms up unevenly ... between T=1s and T=310s, difference in 1-2 head and 3-4 head is about 40deg.

2. Once warmed up the temps are pretty even. "Getting on it" was a little difficult because I quickly exceeded the speed limit in my area Need to get on the highway.

3. I have noise in my Ambient Air Temp and Fan Inlet Temp circuit, will need to fix this.

4. No Oil Temp, RPM, and Rear Wheel Speed circuit yet, will get those running in a few weeks ... so its difficult to judge temps without this data ... how fast was I driving, how high was I revving ect..

More data to come !

Sandeep

[Massive Type IV]

Cool! So what do you have for a scale to transfer these to degrees??

About 60 degrees is the norm for what we saw with the fan you have, shroud you have as well as the drive ratio, but our engine was larger displacement- 2270

Great work! when you get that rig all figured out I'll buy one from you!

[Sandeep]

The chart scale is logorithmic on the y-axis ... so between 1 and 10, the divisions are 1,2,3,4,5,6,7,8,9, and 10, between 10 and 100, the divisions are 10, 20, 30, 40, 50, 60, 70, 80, 90 and then 100, from 100 to 1000, the pattern is the same.

When I get the RPM's hooked up, there will be another section, 1000, 2000, 3000, 4000 etc between 1000 and 10,000.

The temps are in F, AAT and FIT in C.

The logger stores data in hexidecimal format (memory savings) and the calcs tab in the spreadsheet makes the conversions through formulas derived from the circuit I designed. I calibrated the system with a pot of boiling water and I'm only off 1.5 F at 212 F (100 C) when the pot is boiling.

I'm off to do another run now !

Sandeep

[Massive Type IV]

cool....

But you do know that water only bois at 212 when you are at sealevel... You need to do a bit of an equation to figure out your elevation and the differences from sea level..

[Sandeep]

You are right ... Todays pressure is 101.87 KPa and Toronto is at 270m above sea level ... that works out to 210.10 F. Another boiling water test shows the temp on each of the thermocouples at 211.6 F so within about 1.5F. :agree:

I also rerouted my coil spark plug wire and it really helped eliminate most of the noise. 2nd run here.

I won't put up anymore runs until I get the RPM's and RWS sensors hooked up, so I can show the temps at what RPM and RWS.

Sandeep

[Wally]

Originally Posted by Sandeep

2nd run here.

Sandeep

Wow, only maximum 10 degrees Fahrenheit difference and max head temp so far only about 310F ! I am impressed!
To be honest, after all the horror story's of the 911 fan set-ups, I would have expected much higher head temp differences...

Thanks for your effort!

Regards,
Walter

[boygenius]

doesn't the mineral content of water also slightly affect the boiling point. I thought only "pure" water boiled at 212 degrees F at sea level.

[Wally]

Originally Posted by boygenius

doesn't the mineral content of water also slightly affect the boiling point. I thought only "pure" water boiled at 212 degrees F at sea level.

You ARE kidding me, right?