I love my engine. It used to sound like a screaming banshee but now, it's more of a deep F1 sound. Revs like a motorcycle and pulls like a V8. The only thing I possibly would change is running a higher compression. I'd love to figure out some sort of variable intake runner by way of varying the trumpet length.
I suppose variable length trumpets could be achieved by having two different openings... one on the side down low--like an exhaust cut out--the other at the top. It could be designed as mechanically or electronically actuated.