Fixing engine friction torque

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I'm guessing new data is needed before the cars will load with the lastest git? Time to revisit putting the data on github? - Sourceforge's SVN hosting is still down

Yeah, svn has been down for more than a week now.

One concern has been about the amount of data if I remember correctly.

StuntRally ( https://github.com/stuntrally/stuntrally ) has got its data on github. But it will probably be much smaller due to better mesh/texture sharing, have to checkout how large it is.