datsun40146 Posted December 19, 2008 Share Posted December 19, 2008 This was taken from vwvortex.com and I thought it was neat application of mathematics even if it has some error involved. quote" http://www.metacafe.com/watch/...a_car/ I just don’t know...anyone tried it? " Quote Link to comment Share on other sites More sharing options...
blue72 Posted December 19, 2008 Share Posted December 19, 2008 10% margin of error is a great job? Doesn't even take into account temperature or any other variables. Quote Link to comment Share on other sites More sharing options...
Afshin Posted December 19, 2008 Share Posted December 19, 2008 Cool idea! Temperature should not make at difference as it effects psi linearly and is accounted for in the calculation. The main variables that I can think of are tire side wall stiffness, distribution of pressure through out the carcass and measurement error in taking the actual foot print for each tire. Based on these we can expect it not be very accurate for total weight. However most variables are fairly constant between all four tires, so this method could potentially be very useful in figuring out corner weight percentage, notably for those with coilover set ups. I will have to try it. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted December 19, 2008 Share Posted December 19, 2008 Cool idea!The main variables that I can think of are tire side wall stiffness, distribution of pressure through out the carcass and measurement error in taking the actual foot print for each tire. Sidewall stiffness directly affects the footprint size, so I can't see that playing a huge role. Distribution of pressure in the tire is going to be a non-factor. The biggest issue as far as accuracy goes that I see, is that by using 2 straight edges you are assuming the contact patch is flat sided. There will be error induced there, as well as if you don't have those straight edges parallel when you make your measurement you will be inducing error. Very cool video none the less! Quote Link to comment Share on other sites More sharing options...
Afshin Posted December 19, 2008 Share Posted December 19, 2008 It's because side wall stiffness affects the tire patch size, independent of weight and psi, that it would cause some inaccuracies. Since we can't measure the stiffness, we can't account for it. Just picture a run flat tire that will maintain a decent contact patch at 10 psi to a rated H tire at the same psi, it would significantly affect the weight estimate. I do agree that careful squaring of the cardboard to ensure accurate foot print measurement is likely the most important variable. Quote Link to comment Share on other sites More sharing options...
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