XRAY - Model racing cars

Hello everyone,,
I used Martin's setup from the WC with the following changes:
1) Purple front spring instead of red
2) 0.5 caster clip behind the upper arms, instead of 1.5
3) front shocks on the lowest hole (1) on the front tower
4) since I used RB tires, which they have rims with 0 offset, I used the front 0 offset hexagons and the +0.75 in the rear. I think that I have now approximately the same offset with Martin who used the Xray rims, which have offset. Am I correct?
Overall, the car was good and I was chasing the 3rd place when I ran out of fuel. I think though that it needs some fine tuning.
What I experienced is that the car was very twitchy at the high speed turns. To be more specific, I had to be really careful with the steering, because I had too much when I was in high speed parts of the track. While on the slow parts of the track I needed more steering and the car did not react fast to the steering input and I was loosing time waiting for the car to turn in.
At the same time, if it is possible to gain a little more steering while on throttle center and out of a corner will be great.

I would also like to mention that I opened one more hole in the front shocks and the high speed problem became worst. I also put the red front springs and the turn in became worst.

I would appreciate your suggestions.