I have two exactly the same legacy engines, but they run at slightly different speeds. If I start them next to each other, they are a yard apart after a few minutes. Will this be a problem if lashed together?
Fab, The easiest way to find out is to set them up in the same consist, lashed up. Once done, manually uncouple them and leave a 2 inch space. Start them up, push speed control and they should maintain that 2 inch distance.
The more important question is why are they running at different speeds when running independently. How are you setting the speeds of each engine? Are you using the digital Miles per Hour or are you using the "Speed" button? The digital MPH is not accurate. The speed control button works better.
My Legacy engines are pretty good about maintaining the same speed, but I have heard this complaint from others. I am not a "techie" and if the problem continues, I would private message MartyE.
Just to confirm, you ARE using the train link function to create your MU train consist for speed experiments right? If not, it's not a true MU. The Legacy software actually does compensate for the slower or lower geared unit. I found this out when I MU'd a switcher and a Berk (they had WILDLY different gear ratios).