That 'searching' sensation as grip moves from side to side and power understeer in the wet where it jumps a metre off the apex.
Also, suddenly finding a load of grip when it is going very, very wrong can bite. A smash of a friend of mine last summer was 99% down to the diff - he lost the back, it bit on oppo with foot down to correct and it caught grip speared him into the barrier. A normal FWD wouldn't have done what it did.
....Err? Are you talking about an ATB Quaife diff? I suppose if you were driving so that things were "going very very wrong" in the first place then it's not going to save you, but I've found it's been a great help whenever it has (gently but firmly) come into action.
Lose control of a quattro equipped car and it's invariably a biggie.
Yes, a Quaife ATB.
He was crashing anyway, the diff just made for an unusual surprise. He was doing a right hander, lost the back and then as it snapped and got grip it punted him 90 degrees over to the left bonnet first into the barrier. The natural path would have been to keep sliding and send it sideways in, hopefully with a bit more speed scrubbed off.
Anyone can get it wrong though, I've seen a car put on its roof at less than 20mph.
As for the cons I mentioned, fair enough nobody with any sense goes hooning in the rain on the roads - so it jumping into a hedge half way around a corner is highly unlikely, but a wet track day and a diff'd car won't be as progressive as a non.
I'm not running them down, I want a Quaife myself, but you have to make people aware of some of the quirks too, it's not all joy. I wouldn't send my missus out on a rainy day in a diff'd car without showing her what it'll do if you provoke it first. She's a good driver, but having something 'new' happen that might frighten her wouldn't be right.
