[Fot] SU carbs- Fixed needle vs Spring loaded

[George Harmuth]

Racing season is over for me and I'm getting my winter projects lined up.
One is rebuilding/ replacing my carbs, SU H2s, for the Spitfire. I've
collected several sets and I was wondering which type are better for
racing, the fixed needle type or the spring needle? From a theoretical
point of view, I can see pluses and minuses for each type. This year I ran
both types too, but not having identical needles in each, I couldn't do a
real comparison.
I suspect the answer is fixed, but any thoughts?

thanks
mike

63 Spitfire

G. Michael Harmuth