Questions about converting a dynodynamics dyno
Here you go...
This works flawlessly with the inductive clamp.
I also made a lead to use in place of the inductive clamp that can be connected to a coil or injector, but the clamp works so well I haven't used it other than for testing when I made it...
@bendd I have fitted a new 3 wire sensor to the DD bracket, and it is reading the notches. Do you recall the number of notches in the roller? I was unable to find when searching, and figured I'd ask before counting them one by one 🙂 Thanks!
Yeah, it's 96 pulses/revolution. I didn't count them, I extracted that number from the original DD config file so I didn't make an error 🙂
If it helps, use 2.8 kg*m^2 as a starting point for the roller inertia and 43cm for the torque arm.
Assuming yours is the same machine as mine of course 🙂
2. The speed sensor Jostien sells works well with the notches in the DD rollers
I have to correct what I wrote earlier as it was bad advice for anyone converting a Dyno Dynamics DD450 style machine.
The 96 notches in the roller end produce a frequency that is too high at the upper RPM range for the supplied speed sensor and YourDyno box to read correctly.
The max rated roller speed is 5000rpm, so this produces a 8000Hz signal. In other posts on the forum Jostein has recommended a max of 5000Hz.
It worked great up to about 3250 or 3500 (just over 5000Hz - as J advised!) roller RPM but I realised with higher geared cars I was having trouble beyond this roller speed.
I have since fitted 10 magnets (12 would have been a better number) to the shaft and it has transformed the way my dyno works!
Don't underestimate the importance of accurate and noise free dyno speed measurement.
The dyno's primary function is to control the rotational speed of the brake and it cannot do this if the speed measurement is poor!