MAHA LPS 13 project. Many questions
I am Jeroen from the Netherlands and own a workshop that has his specialty in VAG cars. I came across a MAHA LPS 13 Dyno and made an offer and I was the new owner. It is an old analoge Dyno but it have a TELMA CC 160 brake in it and it is nearly used. The paint on the rollers is still there. The bearings are okay and everything on the Dyno is still original. I asked MAHA Netherlands what it would cost to make it digital and they came with a price above 20k euros. So I went to google and soon I found this site and system from Jostein. That made me very happy 😊 I Don't have any experience with a Dyno but I did read a lot about it and now it is no high rocket science for me. I did much reading on this site but I have a lot of questions about the Electronics of te LPS 13. So maybe someone can help me out to find out what kind of eddy current control is originally used. Maybe I can use a piece of the original power supply. Otherwise I think I will buy the sportdevices power-supply. I think I need to replace the RPM sensors. They look to have a very fast signal. (much and smal teeth) I was wondering of the horsepower can be upgraded with software only or do I need a bigger brake? I read that some people measured over 500 horsepower with a TELMA CC 160. Original on the Dyno is 250 horsepower the maximum.
Sorry for my bad English. Google translate is my best friend at the moment 🤣 🤣
I will try to post a few photos of the Dyno on this topic.
Welcome to the forum!
The Telma CC160 can hold 1600 Nm, so for example at 3000 RPM that is 670HP. However the max torque is not constant over the RPM range and the torque capacity falls when it gets hot, so it will be less in practice for at least for long steady state runs. For power runs (sweep the RPM) you have the effect of the Moment of Inertia that helps absorb HP, so that will give higher HP capacity than steady state. So the capacity should be much more than 250HP. I expect it can do 500hp without problems in a power run. Anyone who has a Maha LPS13 can chip in?
For the power supply, they are all roughly the same design but differently made for the different dynos, I don't know this one in particular. But if it works you can try to find an analog signal, typically 0-5V (sometimes 0-10V) that goes to the thyristor/rectifier controller board.
Otherwise SportDevices is an easier path, it works great. Let me know if you are on a budget, there are lower cost alternatives if you are a bit adventurous.
Yes, you need a new RPM sensor. The Maha uses an VR sensor which is not compatible with YourDyno. You also need a new trigger wheel, check the wiki on that.
Thank you for your input. I saw on the powersupply of the brake that there is a SEMIKRON SKB33/08. than it has two wires to the main board. And there ar 2 smal transformators of 18 volts. If someone knows where I can find the wirediagram I think I maybe can find the 5 or 10 volt analog input signal. But the problem is the whole system works on one singel board and there is for example also the low voltage FAN switch from the remote. Also i see some electronics for the analog needles (gauges) on the front of the machine. I will try to make some pictures of it.
That Semikron device is the controlled rectifier. You can try to follow the 2 control signals (the white wires I think) to see where they go. But there does not seem to be a nice small stand-alone power controller there... you get a lot of other "stuff" with it. Probably you could reuse the bridge and buy a controller like the Semikron SKPC 200, I believe it can control that bridge (check the specs).
I' ve been busy with the Dyno last week and made a hole in the floor and gave the Dyno some grease and a fresh paint job. I 'm very enthusiastic about your product. But I have a few questions.
* The loadcell on the MAHA Dyno is not a S type but more a "block". I attached a picture of it. What would be the distance of the measuring point relative to the centre of the brake. Or do I have to change it to a S type. But if so where is the best point to instal it.
* Is it possible to put a company logo in JPG, PDF or other format in the print of the dynograph?
* I am looking for a nice solution to strap down a car as easy and fast as possible and is even with the floor so you don't brake your neck on it when you walk around the dyno if there is no car on it.
* I don't really understand how the load of the cpu of the PC gets more when you have more runs on the screen. I found some information about that on the website but don't understand that. 😊
* What is the average size of the file from one run?
Your Maha is looking good!
For your questions:
- No problem with a bar type sensor. The distance to the sensor is not important, what is important is the distance to the (center of gravity of the) load when you calibrate. But that load cell looks a bit old and taped up, a new one is really not much money, so I would maybe go for that. Even if it works it may not be very linear
- Yes, you can add your company's logo to the printout. Just go to Print page setup
- On the CPU load. If you have very many curves in the same graph then the cursor is lagging a bit with a slow PC. You can move the mouse around and it will find the closest curve and the closest point on that curve and show this. Other than that, if you load up with many sensors (through plugins) then it is quite a lot of calculations every second, so you may need a faster PC. For example you can log and display 8 thermocouples, 5+3 analog sensors plus a whole lot of OBD2 data in addition to controlling 2 brakes and calculating HP/Torque... The PC for our rolling road similar to yours is really low cost though, and it is fine.
- One csv file with a few runs is typically a couple of MB only
Looking forward to seeing your system in action!