Just did my first trackday (altough I go to the 'Ring' for 7 years now) on an airfield.
What I noticed was the enormous amount of understeer that biuld up in the slower corners.
What can I do to prevent this ?

Creepy

 

Change your line, driving style, check tyre pressures etc. Could be anything I found mine was caused by over-heating the front tyre due to low pressures and me being a loon I pumped the tyres up to 40 psi and it was a big improvement but I don't drive a scoob.

Paul

 

Increased tyre pressure is one of the way to prevent this.

When a tyre is low pressure, the tyre walls move a lot and generate heat which reduces the tyres preformance. So a higher pressure is recommended (i use 40psi front & 38psi rear)

Also, i would recommend an adjustable strut brace, as this will stop the front chassis from moving as much under heavy load and keep the car more balanced.

One more step is to do the same as i did and run on slick tyres which are even better (obviously). These are designed to take the punishment of a track, without the degradation that you get with normal road tyres on a track after 7-10 laps! you can pick up used / scrubbed slick (or intermediates) second hand very cheaply.

sly

 

or just go in a tad slower, balance the throttle for the mid bend and then gently push some throttle on as you pass the apex. Try not to yank the lock on either, wind it on gently, knocking it off again if it understeers. You could even try a bit of left foot brake, I've tried it but it didn't seem to have much of an effect!

I think the problem with airfields is that as they're so open, even more so than on a track, you lose the feel of speed so you're probably just going too fast for the bend!