Do you mean compared to the ISF?
Found this online:
You’ll find the same cast-aluminum block that’s now doing business in the IS-F, but everything else about this DOHC 5.0-liter V-8 engine has been revised. Lightweight titanium valves are again matched with strong, forged connecting rods, but there are new cylinder heads that still incorporate variable valve timing on both the intake and exhaust cams. The polished crankshaft is smaller in diameter to reduce friction, while the pistons reduce friction as well. Naturally the intake manifold and exhaust headers are new, and the exhaust barks with a sharper, louder note. This engine spins faster than before to deliver 471bhp.
I also know it has a better ECU map.