Try .5 Shims on top of the C-hub. Also Try Ride TC Pro Match Springs, RED, RED(same as hpi silver, silver). 6.4 Rear Block and change oil to 350, 400, or 450. I think the Yokomo guys running thick oil like 550 may be running larger holes such as 1.2mm. Hayato has told me that 1.0 piston holes with 350 or 450 feels like 500 or 550 with a 1.2 piston holes. He is using 1.2 holes I believe. You can also try lowering your inner camber link to 1mm all around.
Also, I don't know what shock hole you are at in the rear, but sometimes #4 in the rear and #3 in the front feels good. More steering and it feels more direct for me. I see some drivers using #2, #2 with soft setups. I have not tried that yet.
tried a few more stuff to get rid of understeer. next to the body mounted a few mm forward there was only one thing that helped really .... the correct additive. suddenly there was tons of steering and the car acutally flipped in some corners on asphalt because of too much grip. now the car is pretty much perfect.....the driver now has to catch up
