[Trish]

People will maybe disagree with me but Theres a couple of things that come into play.

If you went out with a loose front diff you would find the car more twitchy at the front and have more steering into the corner but coming out the front wouldn't give you as much forward drive out. It would generaly be slightly harder to drive opposed to a tigher diff your car will feel safer but slower round the corners but you will feel you can push it more.
There is a balance between the tightness but that is somthing you will find when you play with it. So you need to find the happy medium.

As for the Rear if you want more rear end grip, have it slighlty looser, but if you want the car to turn in more, you could run a tighten it so to make it break traction. If you kept tightening it would end up with a drift king.

I have always been told to have a tigher front diff but somtimes depending on the track you dont always need it that way round.

Eighth boys play with oils, a heavy oil for more forward drive and lighter oil for a more active diff, this will maybe make the car more nimble suited to the track.

The biggest mistakes I've made on my round one qually is having a loose front diff and then thinking I have to much turn in so there's' me putting a heavy spring on and laying the shocks down on the wishbone and all it was, was my diff being too loose lol.

At the end of the day you can use it as a tuning aid, I'm sure there will be a fair few who will disagree with what I've said so don't take that as gospel!

Just make sure that they have a smooth action to begin with and that they don't slip to much, but I'm sure top racers at the meeting will be able to show you how to check them properly.

Trish