Hi Ross -
Yeah, the car has Yokohama A048Rs which are actually quite grippy initially but don't handle the power too well once properly hot although it always launches well with 3.54 diff / LSD. The car weighs about 950kg with a near 50/50 split so I don't think its a weight issue.
One thing I'm keen to look at now is the suspension geometry as I'm convinced there is time to be had in getting the car more balanced and neutral in response to inputs. I've not driven it in anger yet but pushing on there is definately a tendancy for the car to very quickly become a handful to keep on the track, as you say requiring a lot of steering input.
There is a lot of negative camber on the right front, more so than the left which I am trying to understand as to why it has been previously setup that way. Now the brakes are sorted, a session to get suspension right will prove worthwhile I'm sure.
If anyone has any experience of Griff suspension settings, do please let me know.