Originally posted by redsand
which would be good to run on a small tight and technical track ?
On small to med tracks, the RR12 is the king, but in med to big tracks, nothing is better than a NS12.
You can adjust a little depending which exhaust will use, but answering to your question, your engine is the RR12 (3 or 5 ports - seems that the 5 ports is unavailable at this time).