tyre pressure is what helps
drop it to 20psi in the rears
and dont get your boost controller to trim around gear judge like the avc-r to give you traction
imho if you cant get traction get better rubber, wider rubber, better diff, better suspension etc
you could def do better with 2.3 60ft
with a f**ked diff in my car i was able to get 13.7 @ 105 on my first time at heathcote
also with 0 to 100 4.88s and 4.9s