My mind is wandering - port vs throttle body EFI

[My427stang]

I am with RJP.  You cannot compare FAST and electronic fuel injection because the fuel is under pressure from a pump.  That is not in a carb.

The same reduction in atmospheric pressure is acting on the fuel in the bowl and the air pushing into the carb.  Now that being said, performance and mixture does change with mechanical injection and diesels (nat aspirated mechanical injection) as well as jet engines.  In those cases we have to account for pressure/density altitude, but that is because the fuel is not acted upon in it's sealed system

[andyf]

Aren't there any serious bracket guys on this forum? Those guys break out the jets whenever the DA changes by a few hundred feet of elevation.......

[My427stang]

Aren't there any serious bracket guys on this forum? Those guys break out the jets whenever the DA changes by a few hundred feet of elevation.......

Like I had said prior, I know people say they should do that, and we chased our tail,  but the 10 sec car we play with (440 inch Rat), the owner used to change jets more often than his underwear, and when we started logging with a wideband, the A/F changed when the jets changed, not when we changed tracks or weather.

I think a significant change in ambient temp could drive a jet change, but we haven't even seen that much with a warm engine

[Drew Pojedinec]

Aren't there any serious bracket guys on this forum? Those guys break out the jets whenever the DA changes by a few hundred feet of elevation.......

The "serious bracket guys" I work with leave the carb alone and add ballast
This is south georgia and a sack of corn is cheaper than bowl gaskets and jets......  (plus what Ross so astutely noted regarding a/f ratio)