Excessive oversteer

[CTE]

I have an S1 which is quite well set up but having just done a trackday in it I can confirm that once the back end starts to go, there is not a great deal that can be done about it. Now the conditions in the morning were damp and I am running some pretty basic road tyres, bought more for cheapness and long life. In my mind though I think this helps expose a characteristic at slightly slower speeds.
This car has 700lb in springs at the rear and I think 425lb in at the front. The rear also has assistor springs to help the bump stop. In the dry the car is certainly more forgiving and predictable, although I still managed one spin!! Ha
I used to have a standard road spec S2 and it seemed far less twitchy in this respect.
Is this characteristic typical for an S1?

[CTE]

Ah apologies, just checked and the rears are 600lb in with 250lb in assistors for the bump stops...the guy who set the car up said that fitting slightly softer front springs would induce some understeer...guess the only way to get to the bottom of it is to try various springs and settings?

[CTE]

Yes I agree having read something elsewhere...I think some fine tuning is required with spring rates and toe in...at the moment there is very little rear toe in.