Shock oil ?
 

I bought new shock pistons for my bmax-2 . 1.6x2 flat for front and 1.7x2 flat for rear. Which weight shock oils would be a good starting point for a indoor carpet , tight track ? I'm using losi oils.

Try 40-45 front and 30 rear to start with and go from there.

I use that piston set-up, and run as light as 35 front, 30 rear with a Associated Red spring up front and an Associated White on the rear. Put the rear rear shocks on the middle hole on the arm though to help it stand back up out of corners - works great!

If you experience a too much chassis roll with this lighter oil, move your link positions out on the shock towers to help keep the car roll less :)

I run this same set-up on a very bumpy astroturf track, yet when I go and race indoors it's still great on carpet/slippy flooring.