I'm having a bit of trouble deciding on pistons for my LS/VTEC build, and was wondering why the calculators at Honda B-Series Compression Calculator by ZealAutowerks and Compression Calculator - Honda, Acura Tech Website, tutorials, tuning and HOW-TO's. Drag racing, street racing, road racing - C-speedracing.com are so different in their calculations for the same builds. I was hoping to get about 11.0 compression before shaving the head and block (just to make them flat) and was wondering what piston I would need. The block is a B18A with a 81.5mm bore (will be after boring,) and a B16A head. I was hoping one of the "type R" pistons would get me that 11 compression cause of their skirt coating, but we'll see.