News

As some of you will be aware, Peter Lynn is developing a buggy to make an attempt on the world buggy speed record at NABX in March 2010

During the week Peter built a buggy tire force dynamometer.

Here is a bit of what he had to say about it.

"Basically, the side force generated is set by adjusting the angle of the test tire relative to the direction axis.

The side force this generates is then measured by a load cell and the drag cost of generating this side force is measured by a separate load cell.

The measurements seem to be sufficiently independent for useful conclusions and accuracy should be enough to differentiate bearing drag.

The test wheel is weighted (currently 30kgms, but whatever is of interest), and we can control for speed, surface, and tire pressure.  We'll also record ambient temp. 

When we get to high speeds and small differences I'll also shield the wheel to eliminate aero drag effects.

The version in the attached photo is iteration 3, it has various flexibilities which I'll reduce in iteration 4 - and the right hand trailer wheel axle mount was bent up on account of poor design and Pete's enthusiastic fast driving over pot holes- but it seems fundamentally sound in principle and practise.

I don't yet have a load cell for the drag axis, but the results are already quite interesting. - like that we can wear tires out really quickly!"

 

Peter Lynn, December 2009