Originally posted by Top Gun 777
AAC is better, but irequired certain conditions and different desing then conventional.
Too much to write, just try to look this forum-there is an answer (exclusive nitro zone).
I'm curious... If AAC was better, why did the Kyosho team used the ABC Sirio in the last Pre-Worlds in Brazil?

Would be interested to know as well as the a lot of feedback seems to indicate that the AAC sleeve Sirios are good race engines but unfortunately does not last long.