Speedex Heads

[Tom Coates]

Some of you might be interested in some flowrate measurements I did a while back. These are all on a tuned block with 1.125 in inlet valves, and compares 37 Head with Ricardo and 9E at increasing valve lift. This was measured at a vacuum of 24inH2O and is corrrected for temperature and atmospheric pressure.

Interesting, this seems to confirm the view that there is a trade-off between compression and gas flow, although the ricardo head appears to flow better than the 9E for the same CC volume. Out of interest, was the rest of the inlet tract modified? There aren’t many people willing to share this type of information for A7’s.