[Eljaro]

CalMetal

I used F7 tubes and modified them with a very thin sleeve (0.5mm wall thickness) with 4 holes to partially or totally cover up the bottom holes to see what happened. So I kept doing mods to the sleeve and the emulsion tube until what I had as a result looked exactly like the F14 tube..
But my F7 tube is not a perfect F14 , because the 8 middle holes drilled at an angle are not 100% covered. There is a gap between the sleeve and the smaller diamater part of the tube where these holes end inside the well.
I also had to drill the 4 aditional holes at the top, where the F7 tube has only 4 but the F14 has 8 holes.
With this arrangement I was able to get rid of the bog and the lean condition, according to the OS2 sensor and the gage. Then I went about to reduce the main jet to the point where on full load at 6000 rpm the AFR would stay stable and not go up..
After that the car ran fantastic, I would say perfect. Plugs are tan now, whereas before they were black as a coal mine and no main jet would correct that because smaller jets would lean out at WOT and that is a no-no.
I have ordered a set of F14 tubes and once I have them I will try them out. If I am too rich at the transition I can drill some holes where the F7 has the angled ones and correct for that.