Q&A Forum
Hey guys, I have some questions about Inertia dyno for one axle only with 4 drums, two per tire.
Does anyone know/has some schematics of what material and how to build the drums. What is the good size for the drums like diameter and also what bearings should be used?
I have some ideas about using a big steel pipe for the drums with laser cut sides and steel rod inside for the bearings (of course they will be balanced afterwards) but not sure if they will be with good weight for the purpose.
Any info will be highly appreciated.
Regards, Erik!
Hi have you read the yourdyno interia dyno section and the links Jostien has provide ? If not here is a link to the page
https://yourdyno.com/inertia-dynos/
Yeah, I've read all that info. But I need more detailed information like I said at the top - more specific sizes of rollers etc. More technical info from DIY guys 🙂
Erik
Ok great, What are you planning to test ? Vehicles 2wd or 4wd ? Motorcycles? What would be the maximum horsepower you plan to test?
Have you seen the range dynojet interia dynos they make
I want to test 2wd vehicles, maximum hp not quite sure but close to 500-600whp. I have seen the dynojet inertia dynos but I think it will be easier to find materials for 4 rollers (two per tire)
Erik
500-600whp, good luck with a interia dyno.
Theres a calucator that tells you what size and weight roller youll need to support what power.
A quick google youll probably find a couple calucators.
Will search for such calculators, thank you!
Hope you have access to large lathe , mill and a balancer and you're ready for some heavy duty fabrication.
Yes, I have access to such machinery (a local company can do all of these stuff). Thank you for the link about the calculator, this calculator calculates the mass of the flywheel which is connected to the drums/rollers?
Erik
With this rollers (outside diameter 608mm, inside diameter 32mm) I can test up to 300hp in 3rd speed (tested 535d with 340hp in 3rd speed from 2550 to 4400rpm in 6seconds), 300-400hp in the 4th speed, 5th speed not tested until now.
If you want to use 2 rollers like me you must pay attention to car ground clearance. I can not test cars with sport suspension lowest than 9cm.
some info here http://dtec.net.au/Inertia%20Dyno%20Design%20Guide.htm
Imo it's all too hard basket using a interia chassis dyno ( roller road dynonameter) for vehicle purposes due to the sizes , specially building one from scratch. Maybe ok for motorcycle a interia dyno thats all.
For simplicity, compactness and a wider scope of useage a electric retarder brake chassis or hub dynamometer would be a better option. There are plenty secondhand chassis dyno units floating around.
I might be biased! LOL
Thanks for the info @powertuning thats are some nice drums there.
@Mach_1 can you share with me those second hand dynos preferably located in Europe? 🙂
Erik
What country are you in ? Try the dyno manufactures and sellers in your area as they take in old dyno for trade_ins.