johnm
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- Joined
- Feb 26, 2008
- Messages
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Yes. I once did back to back testing on a dyno with tapered inlet tracts some of which had small upsets in the tube. If anything it improved performance. Possibly because the disturbed airflow improved mixing???There was a mention on a forum some years ago, that a BSA single performed better with a step in the inlet tract. However better performance can be achieved by quite minor adjustments. Personally I would not have the step, but if the port is reshaped to remove it, there might be no easy way back to standard. A tapered manifold might be better.
Anyway steps of 2 mm certainly did not hurt.