darrenjlobb's Rolling Road Chassis Dyno Project

[darrenjlobb]

Bit more work on this in the evenings recently,

Have began the next phase of digitizing the dyno, so that we can do proper power runs / steady state with life computer logging / graphing etc,

First step is to replace the old Clayton VARI-resistors / load cells with some modern digital ones, after doing a evening of calculations, figured out what size I would need:



Bought some M12 rose joints to support it:




Decided to re engineer the "Torque Bridge" so that it sits flush and below the top of the dyno to help with clearances, and so that I can make a flat cover to go on top rather than a lifted one (not ideal with super low cars!)

So made up a new bridge and rose joint mount:



And in position with modifications to the torque arm also:



The more observant of you will notice a change in the load / unload pipework (yes its still a mess, this will get tidied / mounted properly at some point soon!)...I have added one way valves to the stator's outer housing pipes, so that under HIGH rpm full load, it can still add load via the vane (stator pressure rises above pump pressure)...I have also added a stator pressure gauge on the wall so I can monitor the load.
I have also added a "balance" pipe between stators, 10mm pushfit, which keeps the load left to right always the same, so if one brake fills / drains slightly faster or slower, the load is always equalized to keep the power balance as close to 50/50 side to side as we can!

Had to weld some extensions on the arms to keep the load cells in the same position (wanted to keep the same length from shaft to cell as stock so that the calculations were still correct and torque lower)



Mounted the load cell summer on the wall (bought to combine load cell outputs, with trim pots to enable me to calibrate one cell, and then apply the same calibration weight to the other cell and "trim" the output to match the first for 100% accuracy)



Started wiring up the control box, ongoing project, but got the power supplys in, amplifier, and USB I/O for the computer.





And wired up the cells:



The software I am going to be using comes straight out of Victoria, Australia, called "Dynertia". It is designed for both Interia and brake dynos, (and combination of both if you want to pull more than the brakes can hold)

Will enable us to do alot more with the Dyno, gives us 5 input channels of data from just about any sensor we want, so can log / graph boost / AFR / EGT / temp etcetc along side the power graphs. Supports multi-monitor (hence two) to allow live data on a second screen etc, Fairly small concern ran by a guy called Darren (ironically) and really nice chap to talk to / discuss. So will see how it goes, but so far very impressed with the level of options / capacity of the software for what it costs.

Next is to get the roller speed sensor mounted / hooked up, and mount a PC, and begin some initial testing / calibration.

The hardware also has some aux outs, so will enabled me to switch between some presets on the VFD's for extraction etc, so can set it up to run extractor at 1/3 speed when rollers are still, then ramp up as it detects movement, to cut down noise between runs, or anything else you want the computer to run really.

Thanks for reading