I've had two CRTs and I think I can help you out-
Carbon shock towers
Cut the radio tray down
Carbon batt tray supports unless you have RCM tray
ditch the mud guards
PLASTIC SPUR GEAR!!! rotating mass is soooo important
LPR wheels and tires
Run 4s for racing, 5s for bashing. Depending on your heats, you shouldn't need more than a 5000mah 4s1p for racing and whatever you want for bashing.
Titanium turnbuckles and screws (already mentioned)
aftermarket bodies and wings are also usually lighter
Then go practice and get better at setup. Play with shock oils and upgrade to big bores. By the way, here's one of my CRTs. It was built by nl12 but I upgrade and changed a few things to make it lighter and faster...and this was with the Tomahawk aluminum arms and a to of other aluminum upgrades: