ok getting close to starting up my nephews 496 procharged engine
blow thru carb setup.
his fuel regulator has a 1 to 1 boost reference port (allready hooked up)
where should he set his base fuel pressure?
Main thing is to have 5-7psi more fuel psi than boost psi at same time SC is making that boost. Reason is they they oppose each other since bowl vents are pressurized too. Thus reason for boost referenced regulator.
Idle and low power situtions don't need much psi, however I wouldn't have it under 3-4psi.
Be aware that electric fuel psi gauges aren't very accurate.
That said, with the bowl vents being over the throttle blades (restriction) my opinion is to have the boost reference to regulator in same area as the vents. Ie: lower part of the hat or anywhere in the box if using sealed enclosure.If you put the reference port in the intake manifold, then you'll have to deal with different psi/vacuum then the bowl vents see.
Again, it's all about having your normal 5-7psi more fuel psi than air psi your bowls are pressurized at. Just like a non SC carb.
Edit: For those with fuel injectors placed in intake runners of manifold (ie:after t-body and it's blades) then you'd want reference point in intake manifold as the injectors fuel psi will be opposing the psi's in the intake manifold, not those over the t-body and blades.
Thanks CFM, we moved it from the manifold to the hat.
I realized first time on the water we were dealing with
the vacuum at idle changing the regulator. we had the base at 7
and as soon as the throttle blades the pressure would jump to 10.
we are trying it out Friday after work to see if it makes a difference.
yes a mechanical gauge