8 replies to this topic

[Guess-Works.com]

Building a Dyno... ?

Been reading all about the different types of dynos and how they work, with it all boiling down to the ability of measuring the torque produced.

In it's simplest form this would be by the attachment of a device to the crankshaft (flywheel) which when suitable braking force is applied prevents the acceleration of an engine under full throttle.

[Brawlyrox]

it makes me go like this :saywhat:

but u can buy some that plug into a car lighter socket and measures everything off g-force... 0-60, bhp etc etc u can buy them off ebay, not sure if they measure torque tho.

[Madmax]

yeah i know what you mean brawlyrox, but i'd prefer to have it dyno'd. i dont trust those little devices to give me exact figures

[Woody]

those little devices are more accurate than a rolling road dyno (if you beleve the manufacturer and the independant testing done on the instruction sheet !)
but you do need to put your car onto a weighbridge to let it work out BHP .

[Woody]

This guy knows a lot about dynos:
www.diy-nitrous.fsnet.co.uk/index.htm

[Guess-Works.com]

ah.. was reading his other site earlier today..... http://www.dynamometer.fsnet.co.uk/

Also doing some research into telma's ( EM retarders used on trucks )

My thinking is... create a subframe with a telma strapped to the side which is connected directly to the flywheel, then using the EM braking effect of the telma the current required to hold the engine at full throttle will be proportional ( in some way ) to the torque of the engine.

Probably another of the mad capped ideas which will come to nothing, but.... nothing ventured, nothing gained.

Edited by GuessWorks, 15 March 2005 - 08:21 PM.

[Dan]

Do you mean you want to hold the engine still with the dyno and fight against it?

[Guess-Works.com]

Not still, but at a steady rpm, on full throttle.. I like going up a hill

[Dan]

Aaahh good. That makes a lot more sense.

Don't you want to allow the rpm to rise at a steady rate under full load so that you can generate a plot of torque over speed?

I think this sounds like it would work if you had a sensitive enough recording ammeter on the dyno and knew how to do the maths.

You would need to be able to control the temperature of the dyno as obviously this will affect the current drawn by it.

You'd need a big old train or tractor radiator with a fan to connect the engine to.

And you'd probably want to build a test cell (or at least you would the second time you ran it!), engine dyno's are SO LOUD!