Guys, I've always used cams with relatively tight lobe separation values in my hot rods, and been very happy with the performance in every case. It's my personal choice, so let's not get off track and argue about it.

Now, I am just learning about EFI as it relates to hot rod engines. One thing that constantly comes up is "You can't run tight LSA's with EFI." I need help with that. Now please, I fully understand what tight LSA's do to idle quality and engine vacuum.

But here's my main, big, question. Why can't we do away with the IAC, and maybe even closed loop idle if necessary, and just tune the EFI for a suitable idle just the same as we would a carburetor, and be able to run a lopey cam with a tight LSA?? Why, exactly, is it said you can't use a tight LSA with EFI?? What, precisely, prevents it?? If is only the luxury of IAC control, or closed loop idle, I would gladly do without those things. I don't care for computer controlled idle speed on a hot rod anyway!

I will re-phrase the question. I can easily tune a carb to work just fine with a, say, 108 lobe sep cam. What would I have to do to accomplish the same with EFI??

Thanks!!
Vettepilot