Set your turning circle to be somewhere between 3 and 5 feet. With 2x pink apply 50% width additive on the front and set the turning circle to five feet. If you need a bit more steering reduce the circle a bit. Too much additive will make the car oversteer whatever you do to the rate, as will too soft a front tyre. Your current combination is fine for Ardent. Ignore the amount of dual rate people use, as that number depends on all sorts of things to do the Txs and steering geometry differences. Use the diameter of the turning circle as your guide, not a rate number.
Make sure your car turns even diameter circles left and right on full lock - there's a description of that on your RCTech thread.
With respects to Kayce, the 12th differential is the key to good handling. 12th diffs need to be glass smooth and have no slip whatsoever. If the diff is in the least bit tight, the car will tend to understeer in and oversteer out of the turn. 12th cars have to rotate in the turn, and the diff is the key to that. Ignore all you've learnt from TC on setting diffs to give you a bit of drag or limited slip - the 12th diff must be completely free in rotation yet have no slip at all. HTH
