What pistons are people using in their YZ-2's?

[J77MYF]

Has anyone tried non standard pistons in their YZ-2?

If so what are people using??

On smooth tracks it's fine but I raced mine last weekend on a bumpy astro track and it was noticeably bobbing a lot and breaking traction. I watched some other branded cars (this makes me feel ill to say it but KF's) which seemed really smooth and they soaked up the bumps far better.