Q&A Forum
More than two years(!!!) after buying my YourDyno setup, I’ve finally found the time to finish installing it in my Dynojet 250i Dyno (motorcycle chassis dyno)
This is a braked motorcycle dyno I got second hand but brand new. In fact it was still in the crated. Being some years old it was equipped with the older Dynojet electronics, the system they call ‘EX+’
From the very beginning this electronic system has been a real pain, with continuous issues. It failed almost every single time I used the dyno and, as it’s no longer supported by the manufacturer, the repairs were expensive and failed again and again.
So I finally decided to buy a new electronics package and I went the YourDyno way. I got both the V5 DAQ and the power supply. Being the only worker in my very busy Ducati specialist workshop, it’s taken me toooooo long to install it. I must admit that, partly because of the horrible experience with the older electronics, I tended to postpone it in fear of a new set of problems. Not logic in any way but we humans are like that.
Installing YourDyno on my Dyno has not really been a straightforward process BUT this has not been due to YourDyno units (except for a minor issue in the RPM sensor). The problems have come from other components around but have made the process steeper than it should (and, again, have reaffirmed my bad feelings about my dyno)
Besides this, as all the wiring is inside the dyno, I’ve had to remove its covers once and again to check, recheck, undo and do connections until I got everything running.
Now I just have to spend some time exploring and trying to master all the options I need in UnaVision to suit my needs and way of operating the dyno. I’ve read the manual once and again and the options I’ve checked and used have been pretty intuitive and straightforward, so I guess I’ll succeed. I just hope it won’t be a long process.
I’ve also bought a Xencelabs keyboard that has to be configured to suit my needs.
(more topic oriented 'chapters' next)
From a purely mechanical point of view, my Dynojet dyno is really well built and neatly arranged, so I decided to do a tidy job and get the new electronics in the dyno electronics cabinet. As it has a built-in fan (good for the power supply) plus a 15 V power supply for the old EX+ electronics, I’ve fitted the YourDyno units inside as well as two wideband controllers: A ZT-2 and a ZT-3 from Zeitronix which have been very useful in the past and work really well for the money. They’re also very convenient for me as they are the units used by the Woolich Racing system autotune feature.
My dyno is equipped with a double oxygen sensor module operated by compressed air. It allows to work easily on bikes without welding bungs in the exhaust so, I used this to get the AFR readings.
Unfortunately AFR readings showed random values. I tested them both in the controller software and YourDyno V5 analog 1 and 2 inputs with the same results. A couple of new oxygen sensors solved the issue, but it some testing, guesswork and time.
PHONIC WHEEL
As I didn’t find an easy way to fit a phonic wheel on any on the ends of the drum/retarder assembly, I designed and had laser cut a two-piece 40-teeth phonic wheel to bolt on the Dynojet phonic wheel placed in the axle between the drum and the retarder. Being read by an optical sensor, the stock phonic wheel is a thin steel disc with just one tooth, so I found it ideally suited to side-bolt to it my two-piece part.
RPM sensor issues.
In the first test of the YourDyno software, the I got no drum RPM reading. Jostein explained me how to check the sensor and everything seemed normal. Second time it worked and then if failed again.
After again removing the dyno covers to reach the sensor, I finally found the culprit was a bad connection in the sensor connector (brown cable was a bit loose). After refitting the wires in the connector properly, everything worked again.
The brown wire didn't have a good connection (disconnected in the picture)
LOAD CELL
Although my dyno has a retarder from stock, the load cell and torque electronics module are an option my unit didn’t have. As the EX+ electronics is discontinued, it's was not possible to add it. Power sweeps are inertia only and steady state / braked modes don’t provide a torque measurement (!)
The location provided for the optional load cell is held by a solid aluminium rod. However, this location arrangement is ready to fit the load cell not vertically but at an angle of about 20º. Although logic (and Jostein) say it must be vertical I’ve found out this is not really the case. It’s not difficult to modify the dyno to have the cell vertically but I wanted to give it a go.
Here is my logic:
When we calibrate the load cell on the software what we’re saying to the load cell is ‘you are now receiving X Kilograms’. Not being vertical the truth is that the force the load cell is seeing is the vertical load applied times the arccosine of the angle (a bigger force). BUT the load cell DOESN’T know this and, as it behaves in a linear fashion, the reading will always be proportional to the ‘wrong’ calibration force and therefore right.
I’ve been able to verify that this works as in the very first power sweep of a bike, power and torque values match those expected.
The only downside to this is that the load cell will reach its maximum capacity earlier than it would in the vertical position, but if it’s rating is high enough, it will not reach the limit.
Maybe this topic can be controversial but it's what I've done and it works fine. I can always change the orientation, in fact, I have the part made for that if needed.
RPM PICKUP
As my dyno was supplied with a RPM pickup, I tested it with YourDyno and it works perfectly. I found out that one of the pins in the original connector wasn’t in place and was likely at the origin of RPM issues with the EX+ electronics.
Following the instructions from Jostein, I cut the very long original shielded wire and connected it to my V5. Perfect readings with no spikes or any other issue.
CAN BUS ANALYZER
I bought the license for the CAN analyzer in my V5 but I still haven’t been able to use it. Althought my first test bike has a CAN line, YourDyno sees nothing. I did a test with a Kvaser CAN sniffer only to find out that the CAN line in this bike is slower (125 Kb/s) than the slowest (250 Kb/s) option in UnaVision.
So, I’d like to ask for an update to UnaVision to include this slower speed. Newer Ducati models have a 500 Kb/s CAN line but there are still some of these bikes around.
ANALOG 3 INPUT
As Analog and 2 inputs are occupied by my two lambda controllers, I’m foreseeing to use this input for TPS readings, as some of the bikes I work on don’t have a CAN line.
CONNECTION BOX
These three inputs (RPM pickup, CAN line, TPS) must be accessible from outside the cabinet, so I bought a cheap aluminium electronic project box, fitted the connector in it and attached it to the front of the cabinet using the original drills and holes.
MY COMPUTER
Although the fanless computer I used with the older software and electronics worked well, it was too slow according to YourDyno specs. This computer was useful for me as it has serial ports that are the way Zeitronix controllers communicate with their own datalogging software.
I bought a (yes, Chinese) much more powerful fanless PC only to find a very annoying problem I wasn’t able to solve. When the computer was restarted for whatever reason, I lost control of the mouse pointer. It moved randomly by no apparent reason and made the computer unusable. After two days of unsuccessful attempts to solve it, it started to work properly, again for no apparent reason.
I can't see the picture of the phonic whell. I upload it again
Thanks! Very nice installation and great write up!
You are right about the angle of the load cell. It does not need to be 90 degrees to the rotation, because we calibrate it. The load will be higher at an angle as you correctly mention, but this is not a problem if the load cell is dimensioned to include that effect. The load cell will also put a horizontal load on the chassis and brake, but the flex should be minimal and not impact the readings in any noticeable way.