Considering the tight track and the fact there's enough bite:
- Get rid of the +11, run the stock alu chassis instead - the small corners require a short chassis for agility
- Start out using 50g of weight at the front end (under servo, above servo, brass bulkhead, etc). With more weight up front, the amount of front axle load is higher, so the increase and decrease in wheel load from acceleration and deceleration should have less impact.
- Use mid to long wheelbase shimming on the rear arms - this is purely to reduce the rear motor overhang. That, or run mid-motor on medium to short rear arm/wheelbase shimming.
- Remove some rear droop (so when the wheels just touch the ground, the chassis is nearly level) - this will make the rear end looser both on and off-power.
- Put the rear shocks more upright on the tower - it will make the rear end lean in less.
- Use 3 degrees anti-squat - It helps to keep tighter lines on-power (by preventing the rear end from building up as much rear axle load).