Hey Tony Gray, This is a little off the subject but the the BTCC racers used to use viscous diffs in the FF racers. This is a liquid filled diff that worked a alot like a torque converter in an automatic transmission, the more torque put on the diff the tighter it got, it was a exotic & expensive set-up and helped end the series the way we knew it and give us what we have now WTCC(I think this the new name), boring, under powered stock type racer with off the shelf limited slip diffs among other things.