Hi,

Do you have some more info about the dyno you want to make? Do you have any parts already or you start from scratch?

I would do it again, I have many pieces of my old dyno has small diameter rollers

Hi, is it an inertia dyno? Yes, they look quite small, which will limit the horsepower you can run on them. 

With smaller rotors you have less contact patch, meaning the tire will slip easier. You get around this by tying your car down very hard, which will deform the tire, which leads to increased losses. Losses = heat, so you need to keep the run times lower. 

But it is ok as long as your horsepower is not too high. What is the diameter of the rotor and what is the horsepower you plan to test? 

With this size or roll you can easily test 350Hp before you get a spin. The max speed is a problem. Keep the limit at 220km / h

How did they make the load of your dyno? Is there a flywheel present?