minimum engine vacuum needed for EFI

[richiedd]

Hi
have a 70 Firebird with a 30 over 455. The car produces 5 - 7" of vacuum at idle. Butler is telling me that that is too low for EFI systems to self tune and that I will need an expert with a lap top to get it to run properly. Can anybody comment on this...what is the lowest engine vacuum anyone has run on a street system that was able to self tune? What brand system was that?

Thanks for any help/suggestions.

[Hammered]

My EFI 462 ci Pontiac pulls about 10" at idle and is very streetable. The car idles fine at 700 rpm and while I'm not an expert, I did tune it myself versus relying on the self-tuning. 5-7" at idle sounds very low, but 10ish is definitely not a problem. Finally, I think self tuning is over rated, but it shouldn't be a problem at higher rpms. Also know that it doesn't set your afr or timing, only your ve, so you'll need to do some tuning anyways.

[richiedd]

Thanks for the feedback. Did a bit more reading and found the link to the Comp site where the definite opinion is that my vac is a bit on the low side and will need some manual intervention.