Thats dam good 530hp how much fule? If ya dont mind me askin..We have made 530hp with a D66, key really is all in the tuning. I have had guys go from a D66 to a standard H2 and really like the D66 better. They said it spooled quicker and cooled better, modify the H2 then its a different story. Standard H2 is a 62mm inducer compared to the 66mm on a D66 so obviouslythe D66 flows more air.