Mech-Tech in Escondido has a Dyno. They are right next door to my work. PM me if you're doing this and I might join you as well. They have done Dyno days for BMW's before.
He asked for San Diego, not San Dimas...that's like 3 hours from here. Also, Group 5 does not have a Dyno, but they might be able to recommend you a place.