Q&A Forum
Hi
I am just setting up an engine dyno cell using a Stuska absorber and planning to use yourdyno for load control and data acquisition.
I contacted Stuska and sent them a pic of the absorber enquiring about the hp rating, they came back with a range of 650 to 850 depending on the year of manufacture. I have acquired a couple of pumps that should supply enough water to run the brake at around 750 hp if the brake is capable of it.
The first issue I have is load cell size, I tune a variety of engines from around 50 bhp upwards but would like to be able to use the dyno to its max potential if the opportunity arises.
The torque arm on the dyno has 2 positions for the load cell to mount one at around 160 mm c to c and the other at around 325mm c to c. I used the calculator to work out the load cell size which comes out at about 300kg on the longer mounting position.
my main concern is that when I am tuning the smaller engines that the resolution of a large load cell will not be good enough for the small engines, I wondered if anybody has experience in this and if there was any merit in moving the load cell from position to position depending on the expected power of the engine?
The other question is regarding a load control valve, I want to use the stepper motor output to control the load, is there a suitable valve commercially available at a sensible cost ?
I would be grateful for any advice on these issues
regards
Steve
Hi,
Indeed you can use the two positions for powerful and less powerful engines. You need to recalibrate, or you can save the two configurations and restore the one you need.
In general, the load cells are very linear and noise is easy to filter out. But any small amount of drift or inaccuracy in calibration etc will cause a larger error percentwise error on smaller engines, so you are right to be thinking about this.
For the load valve, there is the Land & Sea option, which is over priced in my opinion ($1100 or so), but it is plug and play with YourDyno and includes a stepper and stepper controller. The only other alternative I know about is this one: https://valvesolutions.com/product/v-port-control-ball-valve-series-e/. You need to remove the motor controller and add a (much faster) stepper. I have not seen this in action, but from the specs it looks good.
Hi swmotorsport ( steve) welcome to the forum , what stuska water brake is it ? Why not use the valve that is on it already adaptor a steppermotor to it??
Hi
I think they said its an early version of the xs111 brake.
I bought it from a college for next to nothing but it had been stripped out and put in storage a few years before and none of the pipework, pumps or valves were there so i am having to build all that up myself.
Also the electronics and pc that were with it were ancient so not even wort trying to get working, i figured that updating it with modern data logging and load control would be the best way forward
Hi Steve , that sucks that the valve was lost.
Have a look at Andrew's thread " Scratch built water brake " and post(s) Yourdyno" using a "Land and Sea" valve.
https://swarfman64.blogspot.com/2019/08/thor-washing-machine.html?m=1
Thanks for that info it was very interesting,
I have a lathe and milling machine so I think I should be able to make a similar valve and it definitely wont cost $1100 !
I used a globe valve and fitted a stepper motor to the stem. Verify similar to the original Stuska manual control globe valves which have been converted to electronic control in a similar manner as mine in the past. DEPAC Dave sold a setup that would convert to electronic control back in the day.
I used a globe valve and fitted a stepper motor to the stem. Verify similar to the original Stuska manual control globe valves which have been converted to electronic control in a similar manner as mine in the past. DEPAC Dave sold a setup that would convert to electronic control back in the day.
Hi James Meyers, owner of Depac dyno control systems Dave Manzolini passed away in 2018 https://www.legacy.com/obituaries/berkshire/obituary.aspx?n=david-b-manzolini&pid=191697811
The depac dyno control system considered to be the best in automotive industry.
Care to share dimensional measurement of the valve you used on the stuska water brake? Also what model stuska was it.
How did you global valve conversion characteristically behaved on you dyno?
Hi Swmotorsport, Doesn't matter whether its spherical or cylindrical body shaped ? Don't know!?
Now you have some machining to do and workout the best size and shape of the V-port 15, 20, 30 ..... 45 degrees aperature opening.
23 Mar 2019 — Here are two examples of water brake valves. Notice the very small water passage for low valve openings. See this link on setting up YourDyno https://yourdyno.com/YourDynoHelp/water-brakes/
Characterized and V-Ball Valves Provide Improved Flow Control
simulationHub
Performance Evaluation of Ball Valve for different V-port Angles
Intermediate angle V-Port valves, such as a 30° or 45° balls, produce a modified equal percentage inherent flow characteristic. Slotted balls or V-shaped holes with small angles result in a ball valve with a linear characteristic curve. Figure 6 shows how the flow characteristic varies with characterized ball valves with different wedge angles.
I figure the important part is the linearity of the valve i.e.: 100% open = 100% flow - 50% open = 50% flow etc.
@swmotorsport in my case we use a fire extinguishing system valve, it is linear with a stepper motor and it works excellent
@admin, I am interested to see this design as well
@nsmve that sounds interesting i have ordered a stepper motor and driver but i would be interested in the details of the valve you have used, did you drive it directly from the stepper or did it need to be geared up/down for best results ?
Regards
Steve
@admin