I'm also racing Blackwood in XRG and I have got my times to about 1:38 - 1:40. I'm also using same setup as you are but I modified it a little bit. I'll tell what I'm doing and then maybe somebody can help us both.
You are locking brakes in t1. In my modified setup my brake force is smaller, about 730. This way I don't have to worry about wheels locking. I also changed diff to vicious LSD with 20 torque. I feel it's better.
When your brakes don't lock any more, I think you will feel better braking. In t1 I start braking a little bit earlier than you and I keep standing on brake pedal until I'm slow enough to turn.
I recently watched a Top Gear episode where Jackie Stewart was teaching James May to drive fast and I remember this piece of advice: "you never press the gas pedal until you know that you never have to take it off." I can't really explain it any better.