foxsl

iTrader: (1)

With a fpr regulator like the holley efi in the picture, if naturally aspirated and you only need 58 psi of constant pressure EXACTLY like the vette filter/regulator units provide, do you expose the vaccum port portion to the atmosphere or do you plug it?

Tanus

plug it if you want constant 58psi all time. Id hook to manifold vac port, it lowers the pressure at idle/cruise giving better mpg

foxsl

iTrader: (1)

Oh ok and the reduction in pressure at idle/cruise won't alter the tune if everything was tuned for 58 psi?
The reason I ask is that I'm going from a 190 pump to a larger size and I keep reading that a 255+ pump will over power the vette regulator/filter, raising the pressure and altering the afr.

KENS80V

iTrader: (16)

You are getting some bad info.

Leave the vacuum fitting on the regulator open. Read this (page 3, item #15) http://aeromotiveinc.com/wp-content/...9/12/13101.pdf

Only hook the vacuum to your regulator if your tune is vacuum referenced. Meaning adjustments have been made for this.

foxsl

iTrader: (1)

Thanks for clarifying, open to the atmosphere she goes.

imma_stocker

iTrader: (19)

Yes open to atmosphere is the way to go.

The tune should manage target AFR at idle and partial throttle.