IDI behavioral question?

[larson]

So I ran my front tank out of fuel today and got the ever so popular 2 second nitrous kick but no worries swapped to the back tank and ran with it.
My question is why does it take off like that when the fuel pickup sucks air? I would assume that it would fall on its face immediately with no acceleration feel.

 

[icanfixall]

Thje governor goes into a full advance condition or something like that. As the pressure drops off is when you get so much more advance.. I would wait for Mel to respond because he or Russ will know what happens to make this hp incrase feeling. I too have felt it but for only a few seconds. Then all hell breaks loose when you have no fuel for power.

 

[mblaney]

I bet part of the reason is compress air in the high pressure side. The injector opens (pops) at say 1800 and closes at 1400 (I have seen this on my fancy pressure gauge) and you will get a very measured amount of fuel. With air inclusion, when the injector pops the expanding bubbles results in an uncontrolled amount of fuel (and air) resulting in surging.

That's what I figure anyway.

The governor is centrifugal (all mechanical) so I can't figure how that would cause it but what do I know!

Edit: I also bet that any air coming out of the injector with fuel will result in better atomization.