The roller tappet just rolls on up and over rather than slide. This is a friction reduction freeing up HP in itself.
The roller cam can open up the valves way much quicker, higher and longer than anything else. Those three things add much more power vs. all other style of cams spec per spec.
You can get a solid cam to perform just about dead nearly as well as a solid roller if you order the right lobes to be ground on it and up the anti on the rocker ratio. But in the end, the solid roller wins.
If your in the street, a stout solid cam with 1.6 rockers can have you hauling *** on fire style. There would be no problem creating 550-600 horses with the right parts of course.
For me, stepping up out of that would be a race grind solid roller.
