This is a very interesting thread. I realise that in this instance it is probably too difficult to justify a change in the rear roll centre height, however I wanted to propose REDUCING the rear roll centre height rather than increasing it.
Several things happen when you adjust the roll centre...
I realize that this post is very old, however I found the following SAE paper most useful when I need some Magic formula data on a measured tyre for a range of normal loads.
d'ENTREMONT,K.L., 'The Behavior of Tyre-Force Model Parameters Under Extreme Operating Conditions,' SAE Paper 970558...
