View Single Post
Old 05-15-2019, 11:18 PM
babywag's Avatar
babywag babywag is online now
out of order
Join Date: Jun 08, 2005
Location: Land of froot loops and cukcoo-nuts, CA
Posts: 9,450
ported vacuum is zero @ idle.
manifold vacuum or ported vacuum are identical off/above idle.

with no load having xx* of vacuum advance is not a big deal especially idle or lower rpm.
under heavy load having xx* of vacuum advance can be a big deal aka detonation.
I suggest you plug in a vacuum gauge and watch it.
It is very easy to hit lower vacuum even at part throttle.
You will not have 16* vacuum advance for long using the skinny pedal, even lightly.
Any decrease in vacuum = decrease in vacuum advance.

having vacuum advance in place @ idle tends to give a snappier throttle response vs. having it on ported where cracking the throttle results in a big change in timing.

folks have been arguing about this stuff for decades.
'88 GW (aka Babywag) and '90 GW (aka JUNKbucket) both fuel injected
1994 Caprice wagon
Reply With Quote